import { ApiSignature, ApiType } from '../../components/ApiCode';

Parse, print, and visit GraphQL language source files and AST nodes.

These exports are also available from the root `graphql` package.

For documentation purposes, these exports are grouped into the following categories:

- [AST](/api-v16/language#category-ast)
- [Kinds](/api-v16/language#category-kinds)
- [Lexing](/api-v16/language#category-lexing)
- [Source](/api-v16/language#category-source)
- [Parsing](/api-v16/language#category-parsing)
- [AST Predicates](/api-v16/language#category-ast-predicates)
- [Printing](/api-v16/language#category-printing)
- [Visiting](/api-v16/language#category-visiting)

## Category: AST

<div className="api-category-toc">
  <p>
    <strong>Classes:</strong><br />
    <a href="/api-v16/language#location">Location</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#token">Token</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#astnode">ASTNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#astkindtonode">ASTKindToNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#namenode">NameNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#documentnode">DocumentNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#definitionnode">DefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#executabledefinitionnode">ExecutableDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#operationdefinitionnode">OperationDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#variabledefinitionnode">VariableDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#variablenode">VariableNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#selectionsetnode">SelectionSetNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#selectionnode">SelectionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#fieldnode">FieldNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#argumentnode">ArgumentNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constargumentnode">ConstArgumentNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#fragmentspreadnode">FragmentSpreadNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#inlinefragmentnode">InlineFragmentNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#fragmentdefinitionnode">FragmentDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#valuenode">ValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constvaluenode">ConstValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#intvaluenode">IntValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#floatvaluenode">FloatValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#stringvaluenode">StringValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#booleanvaluenode">BooleanValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#nullvaluenode">NullValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#enumvaluenode">EnumValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#listvaluenode">ListValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constlistvaluenode">ConstListValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#objectvaluenode">ObjectValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constobjectvaluenode">ConstObjectValueNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#objectfieldnode">ObjectFieldNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constobjectfieldnode">ConstObjectFieldNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directivenode">DirectiveNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#constdirectivenode">ConstDirectiveNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typenode">TypeNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#namedtypenode">NamedTypeNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#listtypenode">ListTypeNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#nonnulltypenode">NonNullTypeNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typesystemdefinitionnode">TypeSystemDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#schemadefinitionnode">SchemaDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#operationtypedefinitionnode">OperationTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typedefinitionnode">TypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#scalartypedefinitionnode">ScalarTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#objecttypedefinitionnode">ObjectTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#fielddefinitionnode">FieldDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#inputvaluedefinitionnode">InputValueDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#interfacetypedefinitionnode">InterfaceTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#uniontypedefinitionnode">UnionTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#enumtypedefinitionnode">EnumTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#enumvaluedefinitionnode">EnumValueDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#inputobjecttypedefinitionnode">InputObjectTypeDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directivedefinitionnode">DirectiveDefinitionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typesystemextensionnode">TypeSystemExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#schemaextensionnode">SchemaExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typeextensionnode">TypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#scalartypeextensionnode">ScalarTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#objecttypeextensionnode">ObjectTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#interfacetypeextensionnode">InterfaceTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#uniontypeextensionnode">UnionTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#enumtypeextensionnode">EnumTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#inputobjecttypeextensionnode">InputObjectTypeExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directiveextensionnode">DirectiveExtensionNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#schemacoordinatenode">SchemaCoordinateNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#typecoordinatenode">TypeCoordinateNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#membercoordinatenode">MemberCoordinateNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#argumentcoordinatenode">ArgumentCoordinateNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directivecoordinatenode">DirectiveCoordinateNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directiveargumentcoordinatenode">DirectiveArgumentCoordinateNode</a>
  </p>
</div>

### Classes

#### Location

Contains a range of UTF-8 character offsets and token references that
identify the region of the source from which the AST derived.

<hr className="api-subsection-divider" />

##### Constructor

Creates a Location instance.

**Signature:**

<ApiSignature parts={[["keyword", "new"], " ", ["name", "Location"], "(\n  ", ["parameter", "startToken"], ": ", ["link", "Token", "/api-v16/language#token"], ",\n  ", ["parameter", "endToken"], ": ", ["link", "Token", "/api-v16/language#token"], ",\n  ", ["parameter", "source"], ": ", ["link", "Source", "/api-v16/language#source"], ",\n);"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>startToken</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The start token.</td>
    </tr>
    <tr>
      <td>endToken</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The end token.</td>
    </tr>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>Source document used to derive error locations.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### Members

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>start</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The character offset at which this Node begins.</td>
    </tr>
    <tr>
      <td>end</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The character offset at which this Node ends.</td>
    </tr>
    <tr>
      <td>startToken</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The Token at which this Node begins.</td>
    </tr>
    <tr>
      <td>endToken</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The Token at which this Node ends.</td>
    </tr>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>The Source document the AST represents.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### toJSON()

Returns a JSON representation of this location.

**Signature:**

<ApiSignature parts={[["name", "toJSON"], "(): \u007b\n  ", ["property", "start"], ": ", ["keyword", "number"], ";\n  ", ["property", "end"], ": ", ["keyword", "number"], ";\n\u007d;"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={["\u007b ", ["property", "start"], ": ", ["keyword", "number"], "; ", ["property", "end"], ": ", ["keyword", "number"], " \u007d"]} /></td>
      <td>The JSON-serializable representation.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse } from 'graphql/language';

const document = parse('{ hello }');
const location = document.loc?.toJSON();

location; // => { start: 0, end: 9 }
```

<hr className="api-item-divider" />

#### Token

Represents a range of characters represented by a lexical token
within a Source.

<hr className="api-subsection-divider" />

##### Constructor

Creates a Token instance.

**Signature:**

<ApiSignature parts={[["keyword", "new"], " ", ["name", "Token"], "(\n  ", ["parameter", "kind"], ": ", ["link", "TokenKind", "/api-v16/language#tokenkind"], ",\n  ", ["parameter", "start"], ": ", ["keyword", "number"], ",\n  ", ["parameter", "end"], ": ", ["keyword", "number"], ",\n  ", ["parameter", "line"], ": ", ["keyword", "number"], ",\n  ", ["parameter", "column"], ": ", ["keyword", "number"], ",\n  ", ["parameter", "value"], "?: ", ["keyword", "string"], ",\n);"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "TokenKind", "/api-v16/language#tokenkind"]]} /></td>
      <td>Token kind produced by lexical analysis.</td>
    </tr>
    <tr>
      <td>start</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>Character offset where this token begins.</td>
    </tr>
    <tr>
      <td>end</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>Character offset where this token ends.</td>
    </tr>
    <tr>
      <td>line</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>One-indexed line number where this token begins.</td>
    </tr>
    <tr>
      <td>column</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>One-indexed column number where this token begins.</td>
    </tr>
    <tr>
      <td>value?</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Interpreted value for non-punctuation tokens.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### Members

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "TokenKind", "/api-v16/language#tokenkind"]]} /></td>
      <td>The kind of Token.</td>
    </tr>
    <tr>
      <td>start</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The character offset at which this Node begins.</td>
    </tr>
    <tr>
      <td>end</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The character offset at which this Node ends.</td>
    </tr>
    <tr>
      <td>line</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The 1-indexed line number on which this Token appears.</td>
    </tr>
    <tr>
      <td>column</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The 1-indexed column number at which this Token begins.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>For non-punctuation tokens, represents the interpreted value of the token.<br />
Note: is undefined for punctuation tokens, but typed as string for<br />
convenience in the parser.</td>
    </tr>
    <tr>
      <td>prev</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"], " \u007c ", ["keyword", "null"]]} /></td>
      <td>Tokens exist as nodes in a double-linked-list amongst all tokens<br />
including ignored tokens. &lt;SOF&gt; is always the first node and &lt;EOF&gt;<br />
the last.</td>
    </tr>
    <tr>
      <td>next</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"], " \u007c ", ["keyword", "null"]]} /></td>
      <td>Next token in the token stream, including ignored tokens.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### toJSON()

Returns a JSON representation of this token.

**Signature:**

<ApiSignature parts={[["name", "toJSON"], "(): \u007b\n  ", ["property", "kind"], ": ", ["link", "TokenKind", "/api-v16/language#tokenkind"], ";\n  ", ["property", "value"], "?: ", ["keyword", "string"], ";\n  ", ["property", "line"], ": ", ["keyword", "number"], ";\n  ", ["property", "column"], ": ", ["keyword", "number"], ";\n\u007d;"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={["\u007b\n  ", ["property", "kind"], ": ", ["link", "TokenKind", "/api-v16/language#tokenkind"], ";\n  ", ["property", "value"], "?: ", ["keyword", "string"], ";\n  ", ["property", "line"], ": ", ["keyword", "number"], ";\n  ", ["property", "column"], ": ", ["keyword", "number"], ";\n\u007d"]} /></td>
      <td>The JSON-serializable representation.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Lexer, Source } from 'graphql/language';

const lexer = new Lexer(new Source('{ hello }'));
const token = lexer.advance().toJSON();

token; // => { kind: '{', value: undefined, line: 1, column: 1 }
```

### Types

#### ASTNode

**Type alias.** The list of all possible AST node types.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ASTNode"], " =\n  \u007c ", ["link", "NameNode", "/api-v16/language#namenode"], "\n  \u007c ", ["link", "DocumentNode", "/api-v16/language#documentnode"], "\n  \u007c ", ["link", "OperationDefinitionNode", "/api-v16/language#operationdefinitionnode"], "\n  \u007c ", ["link", "VariableDefinitionNode", "/api-v16/language#variabledefinitionnode"], "\n  \u007c ", ["link", "VariableNode", "/api-v16/language#variablenode"], "\n  \u007c ", ["link", "SelectionSetNode", "/api-v16/language#selectionsetnode"], "\n  \u007c ", ["link", "FieldNode", "/api-v16/language#fieldnode"], "\n  \u007c ", ["link", "ArgumentNode", "/api-v16/language#argumentnode"], "\n  \u007c ", ["link", "FragmentSpreadNode", "/api-v16/language#fragmentspreadnode"], "\n  \u007c ", ["link", "InlineFragmentNode", "/api-v16/language#inlinefragmentnode"], "\n  \u007c ", ["link", "FragmentDefinitionNode", "/api-v16/language#fragmentdefinitionnode"], "\n  \u007c ", ["link", "IntValueNode", "/api-v16/language#intvaluenode"], "\n  \u007c ", ["link", "FloatValueNode", "/api-v16/language#floatvaluenode"], "\n  \u007c ", ["link", "StringValueNode", "/api-v16/language#stringvaluenode"], "\n  \u007c ", ["link", "BooleanValueNode", "/api-v16/language#booleanvaluenode"], "\n  \u007c ", ["link", "NullValueNode", "/api-v16/language#nullvaluenode"], "\n  \u007c ", ["link", "EnumValueNode", "/api-v16/language#enumvaluenode"], "\n  \u007c ", ["link", "ListValueNode", "/api-v16/language#listvaluenode"], "\n  \u007c ", ["link", "ObjectValueNode", "/api-v16/language#objectvaluenode"], "\n  \u007c ", ["link", "ObjectFieldNode", "/api-v16/language#objectfieldnode"], "\n  \u007c ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "\n  \u007c ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "\n  \u007c ", ["link", "ListTypeNode", "/api-v16/language#listtypenode"], "\n  \u007c ", ["link", "NonNullTypeNode", "/api-v16/language#nonnulltypenode"], "\n  \u007c ", ["link", "SchemaDefinitionNode", "/api-v16/language#schemadefinitionnode"], "\n  \u007c ", ["link", "OperationTypeDefinitionNode", "/api-v16/language#operationtypedefinitionnode"], "\n  \u007c ", ["link", "ScalarTypeDefinitionNode", "/api-v16/language#scalartypedefinitionnode"], "\n  \u007c ", ["link", "ObjectTypeDefinitionNode", "/api-v16/language#objecttypedefinitionnode"], "\n  \u007c ", ["link", "FieldDefinitionNode", "/api-v16/language#fielddefinitionnode"], "\n  \u007c ", ["link", "InputValueDefinitionNode", "/api-v16/language#inputvaluedefinitionnode"], "\n  \u007c ", ["link", "InterfaceTypeDefinitionNode", "/api-v16/language#interfacetypedefinitionnode"], "\n  \u007c ", ["link", "UnionTypeDefinitionNode", "/api-v16/language#uniontypedefinitionnode"], "\n  \u007c ", ["link", "EnumTypeDefinitionNode", "/api-v16/language#enumtypedefinitionnode"], "\n  \u007c ", ["link", "EnumValueDefinitionNode", "/api-v16/language#enumvaluedefinitionnode"], "\n  \u007c ", ["link", "InputObjectTypeDefinitionNode", "/api-v16/language#inputobjecttypedefinitionnode"], "\n  \u007c ", ["link", "DirectiveDefinitionNode", "/api-v16/language#directivedefinitionnode"], "\n  \u007c ", ["link", "SchemaExtensionNode", "/api-v16/language#schemaextensionnode"], "\n  \u007c ", ["link", "ScalarTypeExtensionNode", "/api-v16/language#scalartypeextensionnode"], "\n  \u007c ", ["link", "ObjectTypeExtensionNode", "/api-v16/language#objecttypeextensionnode"], "\n  \u007c ", ["link", "InterfaceTypeExtensionNode", "/api-v16/language#interfacetypeextensionnode"], "\n  \u007c ", ["link", "UnionTypeExtensionNode", "/api-v16/language#uniontypeextensionnode"], "\n  \u007c ", ["link", "EnumTypeExtensionNode", "/api-v16/language#enumtypeextensionnode"], "\n  \u007c ", ["link", "InputObjectTypeExtensionNode", "/api-v16/language#inputobjecttypeextensionnode"], "\n  \u007c ", ["link", "DirectiveExtensionNode", "/api-v16/language#directiveextensionnode"], "\n  \u007c ", ["link", "TypeCoordinateNode", "/api-v16/language#typecoordinatenode"], "\n  \u007c ", ["link", "MemberCoordinateNode", "/api-v16/language#membercoordinatenode"], "\n  \u007c ", ["link", "ArgumentCoordinateNode", "/api-v16/language#argumentcoordinatenode"], "\n  \u007c ", ["link", "DirectiveCoordinateNode", "/api-v16/language#directivecoordinatenode"], "\n  \u007c ", ["link", "DirectiveArgumentCoordinateNode", "/api-v16/language#directiveargumentcoordinatenode"], ";"]} />

<hr className="api-item-divider" />

#### ASTKindToNode

**Type alias.** Utility type listing all nodes indexed by their kind.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ASTKindToNode"], " = ", ["type", "mapped object"], ";"]} />

<hr className="api-item-divider" />

#### NameNode

**Interface.** An identifier in a GraphQL document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "NAME", "/api-v16/language#name"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DocumentNode

**Interface.** The root AST node for a parsed GraphQL document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DOCUMENT", "/api-v16/language#document"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>definitions</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DefinitionNode", "/api-v16/language#definitionnode"], "[]"]} /></td>
      <td>Top-level executable and type-system definitions in this document.</td>
    </tr>
    <tr>
      <td>tokenCount?</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The number of lexical tokens parsed for this document, if token counting was enabled.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DefinitionNode

**Type alias.** Any top-level definition that may appear in a GraphQL document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "DefinitionNode"], " =\n  \u007c ", ["link", "ExecutableDefinitionNode", "/api-v16/language#executabledefinitionnode"], "\n  \u007c ", ["link", "TypeSystemDefinitionNode", "/api-v16/language#typesystemdefinitionnode"], "\n  \u007c ", ["link", "TypeSystemExtensionNode", "/api-v16/language#typesystemextensionnode"], ";"]} />

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#### ExecutableDefinitionNode

**Type alias.** Any executable definition that may appear in an operation document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ExecutableDefinitionNode"], " = ", ["link", "OperationDefinitionNode", "/api-v16/language#operationdefinitionnode"], " \u007c ", ["link", "FragmentDefinitionNode", "/api-v16/language#fragmentdefinitionnode"], ";"]} />

<hr className="api-item-divider" />

#### OperationDefinitionNode

**Interface.** A query, mutation, or subscription operation definition.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OPERATION_DEFINITION", "/api-v16/language#operation_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>operation</td>
      <td><ApiType parts={[["link", "OperationTypeNode", "/api-v16/language#operationtypenode"]]} /></td>
      <td>The operation selected for execution.</td>
    </tr>
    <tr>
      <td>name?</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>variableDefinitions?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "VariableDefinitionNode", "/api-v16/language#variabledefinitionnode"], "[]"]} /></td>
      <td>Variable definitions declared by this operation or fragment.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>selectionSet</td>
      <td><ApiType parts={[["link", "SelectionSetNode", "/api-v16/language#selectionsetnode"]]} /></td>
      <td>Selections made by this operation, field, or fragment.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### VariableDefinitionNode

**Interface.** A variable declaration in an operation or legacy fragment definition.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "VARIABLE_DEFINITION", "/api-v16/language#variable_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>variable</td>
      <td><ApiType parts={[["link", "VariableNode", "/api-v16/language#variablenode"]]} /></td>
      <td>The variable being defined or referenced.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
    <tr>
      <td>defaultValue?</td>
      <td><ApiType parts={[["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>Default value used when no explicit value is supplied.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### VariableNode

**Interface.** A variable reference, such as `$id`.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "VARIABLE", "/api-v16/language#variable"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### SelectionSetNode

**Interface.** A set of fields and fragments selected from an object, interface, or union.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "SELECTION_SET", "/api-v16/language#selection_set"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>selections</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "SelectionNode", "/api-v16/language#selectionnode"], "[]"]} /></td>
      <td>Fields and fragments contained in this selection set.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### SelectionNode

**Type alias.** Any selection that may appear inside a selection set.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "SelectionNode"], " =\n  \u007c ", ["link", "FieldNode", "/api-v16/language#fieldnode"], "\n  \u007c ", ["link", "FragmentSpreadNode", "/api-v16/language#fragmentspreadnode"], "\n  \u007c ", ["link", "InlineFragmentNode", "/api-v16/language#inlinefragmentnode"], ";"]} />

<hr className="api-item-divider" />

#### FieldNode

**Interface.** A field selected in an executable GraphQL document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "FIELD", "/api-v16/language#field"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>alias?</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>The response-key alias for this field, if one was supplied.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>arguments?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ArgumentNode", "/api-v16/language#argumentnode"], "[]"]} /></td>
      <td>Arguments supplied to this field, directive, or coordinate.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>selectionSet?</td>
      <td><ApiType parts={[["link", "SelectionSetNode", "/api-v16/language#selectionsetnode"]]} /></td>
      <td>Selections made by this operation, field, or fragment.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### ArgumentNode

**Interface.** An argument supplied to a field or directive.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ARGUMENT", "/api-v16/language#argument"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["link", "ValueNode", "/api-v16/language#valuenode"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### ConstArgumentNode

**Interface.** An argument node whose value is guaranteed to be constant.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ARGUMENT", "/api-v16/language#argument"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### FragmentSpreadNode

**Interface.** A named fragment spread, such as `...userFields`.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "FRAGMENT_SPREAD", "/api-v16/language#fragment_spread"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InlineFragmentNode

**Interface.** An inline fragment spread with an optional type condition.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INLINE_FRAGMENT", "/api-v16/language#inline_fragment"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>typeCondition?</td>
      <td><ApiType parts={[["link", "NamedTypeNode", "/api-v16/language#namedtypenode"]]} /></td>
      <td>The type condition that limits where this fragment applies.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>selectionSet</td>
      <td><ApiType parts={[["link", "SelectionSetNode", "/api-v16/language#selectionsetnode"]]} /></td>
      <td>Selections made by this operation, field, or fragment.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### FragmentDefinitionNode

**Interface.** A reusable fragment definition declared in an executable document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "FRAGMENT_DEFINITION", "/api-v16/language#fragment_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>variableDefinitions?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "VariableDefinitionNode", "/api-v16/language#variabledefinitionnode"], "[]"]} /></td>
      <td>Deprecated variable definitions declared by this legacy fragment<br />
definition. This legacy fragment variable syntax will be removed in v17.<br />
Move variable definitions to operations for spec-compliant documents; if<br />
you need variables or arguments scoped to fragments, v17 has a more<br />
complete experimental fragment-arguments feature.</td>
    </tr>
    <tr>
      <td>typeCondition</td>
      <td><ApiType parts={[["link", "NamedTypeNode", "/api-v16/language#namedtypenode"]]} /></td>
      <td>The type condition that limits where this fragment applies.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "DirectiveNode", "/api-v16/language#directivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>selectionSet</td>
      <td><ApiType parts={[["link", "SelectionSetNode", "/api-v16/language#selectionsetnode"]]} /></td>
      <td>Selections made by this operation, field, or fragment.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### ValueNode

**Type alias.** Any value literal that may appear in an executable GraphQL document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ValueNode"], " =\n  \u007c ", ["link", "VariableNode", "/api-v16/language#variablenode"], "\n  \u007c ", ["link", "IntValueNode", "/api-v16/language#intvaluenode"], "\n  \u007c ", ["link", "FloatValueNode", "/api-v16/language#floatvaluenode"], "\n  \u007c ", ["link", "StringValueNode", "/api-v16/language#stringvaluenode"], "\n  \u007c ", ["link", "BooleanValueNode", "/api-v16/language#booleanvaluenode"], "\n  \u007c ", ["link", "NullValueNode", "/api-v16/language#nullvaluenode"], "\n  \u007c ", ["link", "EnumValueNode", "/api-v16/language#enumvaluenode"], "\n  \u007c ", ["link", "ListValueNode", "/api-v16/language#listvaluenode"], "\n  \u007c ", ["link", "ObjectValueNode", "/api-v16/language#objectvaluenode"], ";"]} />

<hr className="api-item-divider" />

#### ConstValueNode

**Type alias.** Any value literal that is guaranteed not to contain a variable reference.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ConstValueNode"], " =\n  \u007c ", ["link", "IntValueNode", "/api-v16/language#intvaluenode"], "\n  \u007c ", ["link", "FloatValueNode", "/api-v16/language#floatvaluenode"], "\n  \u007c ", ["link", "StringValueNode", "/api-v16/language#stringvaluenode"], "\n  \u007c ", ["link", "BooleanValueNode", "/api-v16/language#booleanvaluenode"], "\n  \u007c ", ["link", "NullValueNode", "/api-v16/language#nullvaluenode"], "\n  \u007c ", ["link", "EnumValueNode", "/api-v16/language#enumvaluenode"], "\n  \u007c ", ["link", "ConstListValueNode", "/api-v16/language#constlistvaluenode"], "\n  \u007c ", ["link", "ConstObjectValueNode", "/api-v16/language#constobjectvaluenode"], ";"]} />

<hr className="api-item-divider" />

#### IntValueNode

**Interface.** An integer value literal.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INT", "/api-v16/language#int"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### FloatValueNode

**Interface.** A floating-point value literal.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "FLOAT", "/api-v16/language#float"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### StringValueNode

**Interface.** A string value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "STRING", "/api-v16/language#string"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
    <tr>
      <td>block?</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>Whether this string was parsed from block string syntax.</td>
    </tr>
  </tbody>
</table>

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#### BooleanValueNode

**Interface.** A boolean value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "BOOLEAN", "/api-v16/language#boolean"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

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#### NullValueNode

**Interface.** A null value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "NULL", "/api-v16/language#null"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
  </tbody>
</table>

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#### EnumValueNode

**Interface.** An enum value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ENUM", "/api-v16/language#enum"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

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#### ListValueNode

**Interface.** A list value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "LIST", "/api-v16/language#list"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>values</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ValueNode", "/api-v16/language#valuenode"], "[]"]} /></td>
      <td>Values contained in this enum, list, or input-object definition.</td>
    </tr>
  </tbody>
</table>

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#### ConstListValueNode

**Interface.** A list value literal whose elements are all constant values.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "LIST", "/api-v16/language#list"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>values</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstValueNode", "/api-v16/language#constvaluenode"], "[]"]} /></td>
      <td>Values contained in this enum, list, or input-object definition.</td>
    </tr>
  </tbody>
</table>

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#### ObjectValueNode

**Interface.** An input object value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT", "/api-v16/language#object"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>fields</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ObjectFieldNode", "/api-v16/language#objectfieldnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

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#### ConstObjectValueNode

**Interface.** An input object value literal whose fields are all constant values.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT", "/api-v16/language#object"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>fields</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstObjectFieldNode", "/api-v16/language#constobjectfieldnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

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#### ObjectFieldNode

**Interface.** A field inside an input object value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT_FIELD", "/api-v16/language#object_field"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["link", "ValueNode", "/api-v16/language#valuenode"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

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#### ConstObjectFieldNode

**Interface.** A field inside a constant input object value literal.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT_FIELD", "/api-v16/language#object_field"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>value</td>
      <td><ApiType parts={[["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>Parsed value represented by this node.</td>
    </tr>
  </tbody>
</table>

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#### DirectiveNode

**Interface.** A directive applied to an executable or type-system location.

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<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE", "/api-v16/language#directive"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>arguments?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ArgumentNode", "/api-v16/language#argumentnode"], "[]"]} /></td>
      <td>Arguments supplied to this field, directive, or coordinate.</td>
    </tr>
  </tbody>
</table>

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#### ConstDirectiveNode

**Interface.** A directive whose arguments are all constant values.

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<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE", "/api-v16/language#directive"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>arguments?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstArgumentNode", "/api-v16/language#constargumentnode"], "[]"]} /></td>
      <td>Arguments supplied to this field, directive, or coordinate.</td>
    </tr>
  </tbody>
</table>

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#### TypeNode

**Type alias.** Any GraphQL type reference AST node.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TypeNode"], " =\n  \u007c ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "\n  \u007c ", ["link", "ListTypeNode", "/api-v16/language#listtypenode"], "\n  \u007c ", ["link", "NonNullTypeNode", "/api-v16/language#nonnulltypenode"], ";"]} />

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#### NamedTypeNode

**Interface.** A named type reference.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "NAMED_TYPE", "/api-v16/language#named_type"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
  </tbody>
</table>

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#### ListTypeNode

**Interface.** A list type reference.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "LIST_TYPE", "/api-v16/language#list_type"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### NonNullTypeNode

**Interface.** A non-null type reference.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "NON_NULL_TYPE", "/api-v16/language#non_null_type"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], " \u007c ", ["link", "ListTypeNode", "/api-v16/language#listtypenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
  </tbody>
</table>

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#### TypeSystemDefinitionNode

**Type alias.** Any type-system definition that may appear in a schema document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TypeSystemDefinitionNode"], " =\n  \u007c ", ["link", "SchemaDefinitionNode", "/api-v16/language#schemadefinitionnode"], "\n  \u007c ", ["link", "TypeDefinitionNode", "/api-v16/language#typedefinitionnode"], "\n  \u007c ", ["link", "DirectiveDefinitionNode", "/api-v16/language#directivedefinitionnode"], ";"]} />

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#### SchemaDefinitionNode

**Interface.** A schema definition in a type-system document.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "SCHEMA_DEFINITION", "/api-v16/language#schema_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>operationTypes</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "OperationTypeDefinitionNode", "/api-v16/language#operationtypedefinitionnode"], "[]"]} /></td>
      <td>Root operation types declared by this schema definition or extension.</td>
    </tr>
  </tbody>
</table>

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#### OperationTypeDefinitionNode

**Interface.** A root operation type declaration inside a schema definition or extension.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OPERATION_TYPE_DEFINITION", "/api-v16/language#operation_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>operation</td>
      <td><ApiType parts={[["link", "OperationTypeNode", "/api-v16/language#operationtypenode"]]} /></td>
      <td>The operation selected for execution.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "NamedTypeNode", "/api-v16/language#namedtypenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### TypeDefinitionNode

**Type alias.** Any named type definition that may appear in a schema document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TypeDefinitionNode"], " =\n  \u007c ", ["link", "ScalarTypeDefinitionNode", "/api-v16/language#scalartypedefinitionnode"], "\n  \u007c ", ["link", "ObjectTypeDefinitionNode", "/api-v16/language#objecttypedefinitionnode"], "\n  \u007c ", ["link", "InterfaceTypeDefinitionNode", "/api-v16/language#interfacetypedefinitionnode"], "\n  \u007c ", ["link", "UnionTypeDefinitionNode", "/api-v16/language#uniontypedefinitionnode"], "\n  \u007c ", ["link", "EnumTypeDefinitionNode", "/api-v16/language#enumtypedefinitionnode"], "\n  \u007c ", ["link", "InputObjectTypeDefinitionNode", "/api-v16/language#inputobjecttypedefinitionnode"], ";"]} />

<hr className="api-item-divider" />

#### ScalarTypeDefinitionNode

**Interface.** A scalar type definition in a type-system document.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "SCALAR_TYPE_DEFINITION", "/api-v16/language#scalar_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

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#### ObjectTypeDefinitionNode

**Interface.** An object type definition in a type-system document.

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<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT_TYPE_DEFINITION", "/api-v16/language#object_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>interfaces?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Interfaces implemented by this object or interface type.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "FieldDefinitionNode", "/api-v16/language#fielddefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### FieldDefinitionNode

**Interface.** A field definition declared by an object or interface type.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "FIELD_DEFINITION", "/api-v16/language#field_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>arguments?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "InputValueDefinitionNode", "/api-v16/language#inputvaluedefinitionnode"], "[]"]} /></td>
      <td>Arguments supplied to this field, directive, or coordinate.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InputValueDefinitionNode

**Interface.** An argument or input-field definition.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INPUT_VALUE_DEFINITION", "/api-v16/language#input_value_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>type</td>
      <td><ApiType parts={[["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>The GraphQL type reference or runtime type for this element.</td>
    </tr>
    <tr>
      <td>defaultValue?</td>
      <td><ApiType parts={[["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>Default value used when no explicit value is supplied.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InterfaceTypeDefinitionNode

**Interface.** An interface type definition in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INTERFACE_TYPE_DEFINITION", "/api-v16/language#interface_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>interfaces?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Interfaces implemented by this object or interface type.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "FieldDefinitionNode", "/api-v16/language#fielddefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### UnionTypeDefinitionNode

**Interface.** A union type definition in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "UNION_TYPE_DEFINITION", "/api-v16/language#union_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>types?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Object types that belong to this union type.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### EnumTypeDefinitionNode

**Interface.** An enum type definition in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ENUM_TYPE_DEFINITION", "/api-v16/language#enum_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>values?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "EnumValueDefinitionNode", "/api-v16/language#enumvaluedefinitionnode"], "[]"]} /></td>
      <td>Values contained in this enum, list, or input-object definition.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### EnumValueDefinitionNode

**Interface.** An enum value definition.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ENUM_VALUE_DEFINITION", "/api-v16/language#enum_value_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InputObjectTypeDefinitionNode

**Interface.** An input object type definition in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INPUT_OBJECT_TYPE_DEFINITION", "/api-v16/language#input_object_type_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "InputValueDefinitionNode", "/api-v16/language#inputvaluedefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DirectiveDefinitionNode

**Interface.** A directive definition in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE_DEFINITION", "/api-v16/language#directive_definition"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>description?</td>
      <td><ApiType parts={[["link", "StringValueNode", "/api-v16/language#stringvaluenode"]]} /></td>
      <td>The optional GraphQL description associated with this definition.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>arguments?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "InputValueDefinitionNode", "/api-v16/language#inputvaluedefinitionnode"], "[]"]} /></td>
      <td>Arguments supplied to this field, directive, or coordinate.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>repeatable</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>Whether this directive may appear more than once at the same location.</td>
    </tr>
    <tr>
      <td>locations</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NameNode", "/api-v16/language#namenode"], "[]"]} /></td>
      <td>Locations where this directive may be applied.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### TypeSystemExtensionNode

**Type alias.** Any type-system extension that may appear in a schema extension document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TypeSystemExtensionNode"], " =\n  \u007c ", ["link", "SchemaExtensionNode", "/api-v16/language#schemaextensionnode"], "\n  \u007c ", ["link", "TypeExtensionNode", "/api-v16/language#typeextensionnode"], "\n  \u007c ", ["link", "DirectiveExtensionNode", "/api-v16/language#directiveextensionnode"], ";"]} />

<hr className="api-item-divider" />

#### SchemaExtensionNode

**Interface.** A schema extension in a type-system document.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "SCHEMA_EXTENSION", "/api-v16/language#schema_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>operationTypes?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "OperationTypeDefinitionNode", "/api-v16/language#operationtypedefinitionnode"], "[]"]} /></td>
      <td>Root operation types declared by this schema definition or extension.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### TypeExtensionNode

**Type alias.** Any named type extension that may appear in a schema extension document.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TypeExtensionNode"], " =\n  \u007c ", ["link", "ScalarTypeExtensionNode", "/api-v16/language#scalartypeextensionnode"], "\n  \u007c ", ["link", "ObjectTypeExtensionNode", "/api-v16/language#objecttypeextensionnode"], "\n  \u007c ", ["link", "InterfaceTypeExtensionNode", "/api-v16/language#interfacetypeextensionnode"], "\n  \u007c ", ["link", "UnionTypeExtensionNode", "/api-v16/language#uniontypeextensionnode"], "\n  \u007c ", ["link", "EnumTypeExtensionNode", "/api-v16/language#enumtypeextensionnode"], "\n  \u007c ", ["link", "InputObjectTypeExtensionNode", "/api-v16/language#inputobjecttypeextensionnode"], ";"]} />

<hr className="api-item-divider" />

#### ScalarTypeExtensionNode

**Interface.** A scalar type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "SCALAR_TYPE_EXTENSION", "/api-v16/language#scalar_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### ObjectTypeExtensionNode

**Interface.** An object type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "OBJECT_TYPE_EXTENSION", "/api-v16/language#object_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>interfaces?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Interfaces implemented by this object or interface type.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "FieldDefinitionNode", "/api-v16/language#fielddefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InterfaceTypeExtensionNode

**Interface.** An interface type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INTERFACE_TYPE_EXTENSION", "/api-v16/language#interface_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>interfaces?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Interfaces implemented by this object or interface type.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "FieldDefinitionNode", "/api-v16/language#fielddefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### UnionTypeExtensionNode

**Interface.** A union type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "UNION_TYPE_EXTENSION", "/api-v16/language#union_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>types?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "NamedTypeNode", "/api-v16/language#namedtypenode"], "[]"]} /></td>
      <td>Object types that belong to this union type.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### EnumTypeExtensionNode

**Interface.** An enum type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ENUM_TYPE_EXTENSION", "/api-v16/language#enum_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>values?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "EnumValueDefinitionNode", "/api-v16/language#enumvaluedefinitionnode"], "[]"]} /></td>
      <td>Values contained in this enum, list, or input-object definition.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### InputObjectTypeExtensionNode

**Interface.** An input object type extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "INPUT_OBJECT_TYPE_EXTENSION", "/api-v16/language#input_object_type_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
    <tr>
      <td>fields?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "InputValueDefinitionNode", "/api-v16/language#inputvaluedefinitionnode"], "[]"]} /></td>
      <td>Fields declared by this object, interface, input object, or literal.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DirectiveExtensionNode

**Interface.** A directive extension.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE_EXTENSION", "/api-v16/language#directive_extension"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>directives?</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ConstDirectiveNode", "/api-v16/language#constdirectivenode"], "[]"]} /></td>
      <td>Directives available in this schema or applied to this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### SchemaCoordinateNode

**Type alias.** Any AST node representing a GraphQL schema coordinate.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "SchemaCoordinateNode"], " =\n  \u007c ", ["link", "TypeCoordinateNode", "/api-v16/language#typecoordinatenode"], "\n  \u007c ", ["link", "MemberCoordinateNode", "/api-v16/language#membercoordinatenode"], "\n  \u007c ", ["link", "ArgumentCoordinateNode", "/api-v16/language#argumentcoordinatenode"], "\n  \u007c ", ["link", "DirectiveCoordinateNode", "/api-v16/language#directivecoordinatenode"], "\n  \u007c ", ["link", "DirectiveArgumentCoordinateNode", "/api-v16/language#directiveargumentcoordinatenode"], ";"]} />

<hr className="api-item-divider" />

#### TypeCoordinateNode

**Interface.** A schema coordinate that refers to a named type.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "TYPE_COORDINATE", "/api-v16/language#type_coordinate"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### MemberCoordinateNode

**Interface.** A schema coordinate that refers to a member of a named type.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "MEMBER_COORDINATE", "/api-v16/language#member_coordinate"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>memberName</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>The member name referenced by this schema coordinate.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### ArgumentCoordinateNode

**Interface.** A schema coordinate that refers to a field or directive argument.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "ARGUMENT_COORDINATE", "/api-v16/language#argument_coordinate"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>fieldName</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>The field name referenced by this schema coordinate.</td>
    </tr>
    <tr>
      <td>argumentName</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>The argument name referenced by this schema coordinate.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DirectiveCoordinateNode

**Interface.** A schema coordinate that refers to a directive.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE_COORDINATE", "/api-v16/language#directive_coordinate"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DirectiveArgumentCoordinateNode

**Interface.** A schema coordinate that refers to a directive argument.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "DIRECTIVE_ARGUMENT_COORDINATE", "/api-v16/language#directive_argument_coordinate"]]} /></td>
      <td>The discriminator identifying the concrete AST or introspection kind.</td>
    </tr>
    <tr>
      <td>loc?</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The source location for this AST node, if location tracking was enabled.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>Name node identifying this AST node.</td>
    </tr>
    <tr>
      <td>argumentName</td>
      <td><ApiType parts={[["link", "NameNode", "/api-v16/language#namenode"]]} /></td>
      <td>The argument name referenced by this schema coordinate.</td>
    </tr>
  </tbody>
</table>

## Category: Kinds

<div className="api-category-toc">
  <p>
    <strong>Enumerations:</strong><br />
    <a href="/api-v16/language#operationtypenode">OperationTypeNode</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#directivelocation">DirectiveLocation</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#kind">Kind</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#directivelocationenum">DirectiveLocationEnum</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#kindenum">KindEnum</a>
  </p>
</div>

### Enumerations

#### OperationTypeNode

**Enumeration.** The operation types supported by GraphQL executable definitions.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Value</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><code>{"QUERY"}</code></td>
      <td><code>{"\"query\""}</code></td>
      <td>A query operation.</td>
    </tr>
    <tr>
      <td><code>{"MUTATION"}</code></td>
      <td><code>{"\"mutation\""}</code></td>
      <td>A mutation operation.</td>
    </tr>
    <tr>
      <td><code>{"SUBSCRIPTION"}</code></td>
      <td><code>{"\"subscription\""}</code></td>
      <td>A subscription operation.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### DirectiveLocation

**Enumeration.** The set of allowed directive location values.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Value</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><code>{"QUERY"}</code></td>
      <td><code>{"\"QUERY\""}</code></td>
      <td>Directive location for query operations.</td>
    </tr>
    <tr>
      <td><code>{"MUTATION"}</code></td>
      <td><code>{"\"MUTATION\""}</code></td>
      <td>Directive location for mutation operations.</td>
    </tr>
    <tr>
      <td><code>{"SUBSCRIPTION"}</code></td>
      <td><code>{"\"SUBSCRIPTION\""}</code></td>
      <td>Directive location for subscription operations.</td>
    </tr>
    <tr>
      <td><code>{"FIELD"}</code></td>
      <td><code>{"\"FIELD\""}</code></td>
      <td>Directive location for field selections.</td>
    </tr>
    <tr>
      <td><code>{"FRAGMENT_DEFINITION"}</code></td>
      <td><code>{"\"FRAGMENT_DEFINITION\""}</code></td>
      <td>Directive location for fragment definitions.</td>
    </tr>
    <tr>
      <td><code>{"FRAGMENT_SPREAD"}</code></td>
      <td><code>{"\"FRAGMENT_SPREAD\""}</code></td>
      <td>Directive location for fragment spreads.</td>
    </tr>
    <tr>
      <td><code>{"INLINE_FRAGMENT"}</code></td>
      <td><code>{"\"INLINE_FRAGMENT\""}</code></td>
      <td>Directive location for inline fragments.</td>
    </tr>
    <tr>
      <td><code>{"VARIABLE_DEFINITION"}</code></td>
      <td><code>{"\"VARIABLE_DEFINITION\""}</code></td>
      <td>Directive location for variable definitions.</td>
    </tr>
    <tr>
      <td><code>{"SCHEMA"}</code></td>
      <td><code>{"\"SCHEMA\""}</code></td>
      <td>Directive location for schema definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"SCALAR"}</code></td>
      <td><code>{"\"SCALAR\""}</code></td>
      <td>Directive location for scalar type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"OBJECT"}</code></td>
      <td><code>{"\"OBJECT\""}</code></td>
      <td>Directive location for object type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"FIELD_DEFINITION"}</code></td>
      <td><code>{"\"FIELD_DEFINITION\""}</code></td>
      <td>Directive location for field definitions.</td>
    </tr>
    <tr>
      <td><code>{"ARGUMENT_DEFINITION"}</code></td>
      <td><code>{"\"ARGUMENT_DEFINITION\""}</code></td>
      <td>Directive location for argument definitions.</td>
    </tr>
    <tr>
      <td><code>{"INTERFACE"}</code></td>
      <td><code>{"\"INTERFACE\""}</code></td>
      <td>Directive location for interface type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"UNION"}</code></td>
      <td><code>{"\"UNION\""}</code></td>
      <td>Directive location for union type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"ENUM"}</code></td>
      <td><code>{"\"ENUM\""}</code></td>
      <td>Directive location for enum type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"ENUM_VALUE"}</code></td>
      <td><code>{"\"ENUM_VALUE\""}</code></td>
      <td>Directive location for enum value definitions.</td>
    </tr>
    <tr>
      <td><code>{"INPUT_OBJECT"}</code></td>
      <td><code>{"\"INPUT_OBJECT\""}</code></td>
      <td>Directive location for input object type definitions and extensions.</td>
    </tr>
    <tr>
      <td><code>{"INPUT_FIELD_DEFINITION"}</code></td>
      <td><code>{"\"INPUT_FIELD_DEFINITION\""}</code></td>
      <td>Directive location for input object field definitions.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE_DEFINITION"}</code></td>
      <td><code>{"\"DIRECTIVE_DEFINITION\""}</code></td>
      <td>Directive location for directive definitions and extensions.</td>
    </tr>
  </tbody>
</table>

<hr className="api-item-divider" />

#### Kind

**Enumeration.** The set of allowed kind values for AST nodes.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Value</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><code>{"NAME"}</code></td>
      <td><code>{"\"Name\""}</code></td>
      <td>AST kind for name nodes.</td>
    </tr>
    <tr>
      <td><code>{"DOCUMENT"}</code></td>
      <td><code>{"\"Document\""}</code></td>
      <td>AST kind for document nodes.</td>
    </tr>
    <tr>
      <td><code>{"OPERATION_DEFINITION"}</code></td>
      <td><code>{"\"OperationDefinition\""}</code></td>
      <td>AST kind for operation definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"VARIABLE_DEFINITION"}</code></td>
      <td><code>{"\"VariableDefinition\""}</code></td>
      <td>AST kind for variable definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"SELECTION_SET"}</code></td>
      <td><code>{"\"SelectionSet\""}</code></td>
      <td>AST kind for selection set nodes.</td>
    </tr>
    <tr>
      <td><code>{"FIELD"}</code></td>
      <td><code>{"\"Field\""}</code></td>
      <td>AST kind for field selection nodes.</td>
    </tr>
    <tr>
      <td><code>{"ARGUMENT"}</code></td>
      <td><code>{"\"Argument\""}</code></td>
      <td>AST kind for argument nodes.</td>
    </tr>
    <tr>
      <td><code>{"FRAGMENT_SPREAD"}</code></td>
      <td><code>{"\"FragmentSpread\""}</code></td>
      <td>AST kind for fragment spread nodes.</td>
    </tr>
    <tr>
      <td><code>{"INLINE_FRAGMENT"}</code></td>
      <td><code>{"\"InlineFragment\""}</code></td>
      <td>AST kind for inline fragment nodes.</td>
    </tr>
    <tr>
      <td><code>{"FRAGMENT_DEFINITION"}</code></td>
      <td><code>{"\"FragmentDefinition\""}</code></td>
      <td>AST kind for fragment definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"VARIABLE"}</code></td>
      <td><code>{"\"Variable\""}</code></td>
      <td>AST kind for variable reference nodes.</td>
    </tr>
    <tr>
      <td><code>{"INT"}</code></td>
      <td><code>{"\"IntValue\""}</code></td>
      <td>AST kind for integer value nodes.</td>
    </tr>
    <tr>
      <td><code>{"FLOAT"}</code></td>
      <td><code>{"\"FloatValue\""}</code></td>
      <td>AST kind for floating-point value nodes.</td>
    </tr>
    <tr>
      <td><code>{"STRING"}</code></td>
      <td><code>{"\"StringValue\""}</code></td>
      <td>AST kind for string value nodes.</td>
    </tr>
    <tr>
      <td><code>{"BOOLEAN"}</code></td>
      <td><code>{"\"BooleanValue\""}</code></td>
      <td>AST kind for boolean value nodes.</td>
    </tr>
    <tr>
      <td><code>{"NULL"}</code></td>
      <td><code>{"\"NullValue\""}</code></td>
      <td>AST kind for null value nodes.</td>
    </tr>
    <tr>
      <td><code>{"ENUM"}</code></td>
      <td><code>{"\"EnumValue\""}</code></td>
      <td>AST kind for enum value nodes.</td>
    </tr>
    <tr>
      <td><code>{"LIST"}</code></td>
      <td><code>{"\"ListValue\""}</code></td>
      <td>AST kind for list value nodes.</td>
    </tr>
    <tr>
      <td><code>{"OBJECT"}</code></td>
      <td><code>{"\"ObjectValue\""}</code></td>
      <td>AST kind for object value nodes.</td>
    </tr>
    <tr>
      <td><code>{"OBJECT_FIELD"}</code></td>
      <td><code>{"\"ObjectField\""}</code></td>
      <td>AST kind for object field nodes.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE"}</code></td>
      <td><code>{"\"Directive\""}</code></td>
      <td>AST kind for directive nodes.</td>
    </tr>
    <tr>
      <td><code>{"NAMED_TYPE"}</code></td>
      <td><code>{"\"NamedType\""}</code></td>
      <td>AST kind for named type reference nodes.</td>
    </tr>
    <tr>
      <td><code>{"LIST_TYPE"}</code></td>
      <td><code>{"\"ListType\""}</code></td>
      <td>AST kind for list type reference nodes.</td>
    </tr>
    <tr>
      <td><code>{"NON_NULL_TYPE"}</code></td>
      <td><code>{"\"NonNullType\""}</code></td>
      <td>AST kind for non-null type reference nodes.</td>
    </tr>
    <tr>
      <td><code>{"SCHEMA_DEFINITION"}</code></td>
      <td><code>{"\"SchemaDefinition\""}</code></td>
      <td>AST kind for schema definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"OPERATION_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"OperationTypeDefinition\""}</code></td>
      <td>AST kind for operation type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"SCALAR_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"ScalarTypeDefinition\""}</code></td>
      <td>AST kind for scalar type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"OBJECT_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"ObjectTypeDefinition\""}</code></td>
      <td>AST kind for object type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"FIELD_DEFINITION"}</code></td>
      <td><code>{"\"FieldDefinition\""}</code></td>
      <td>AST kind for field definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"INPUT_VALUE_DEFINITION"}</code></td>
      <td><code>{"\"InputValueDefinition\""}</code></td>
      <td>AST kind for input value definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"INTERFACE_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"InterfaceTypeDefinition\""}</code></td>
      <td>AST kind for interface type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"UNION_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"UnionTypeDefinition\""}</code></td>
      <td>AST kind for union type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"ENUM_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"EnumTypeDefinition\""}</code></td>
      <td>AST kind for enum type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"ENUM_VALUE_DEFINITION"}</code></td>
      <td><code>{"\"EnumValueDefinition\""}</code></td>
      <td>AST kind for enum value definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"INPUT_OBJECT_TYPE_DEFINITION"}</code></td>
      <td><code>{"\"InputObjectTypeDefinition\""}</code></td>
      <td>AST kind for input object type definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE_DEFINITION"}</code></td>
      <td><code>{"\"DirectiveDefinition\""}</code></td>
      <td>AST kind for directive definition nodes.</td>
    </tr>
    <tr>
      <td><code>{"SCHEMA_EXTENSION"}</code></td>
      <td><code>{"\"SchemaExtension\""}</code></td>
      <td>AST kind for schema extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE_EXTENSION"}</code></td>
      <td><code>{"\"DirectiveExtension\""}</code></td>
      <td>AST kind for directive extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"SCALAR_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"ScalarTypeExtension\""}</code></td>
      <td>AST kind for scalar type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"OBJECT_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"ObjectTypeExtension\""}</code></td>
      <td>AST kind for object type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"INTERFACE_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"InterfaceTypeExtension\""}</code></td>
      <td>AST kind for interface type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"UNION_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"UnionTypeExtension\""}</code></td>
      <td>AST kind for union type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"ENUM_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"EnumTypeExtension\""}</code></td>
      <td>AST kind for enum type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"INPUT_OBJECT_TYPE_EXTENSION"}</code></td>
      <td><code>{"\"InputObjectTypeExtension\""}</code></td>
      <td>AST kind for input object type extension nodes.</td>
    </tr>
    <tr>
      <td><code>{"TYPE_COORDINATE"}</code></td>
      <td><code>{"\"TypeCoordinate\""}</code></td>
      <td>AST kind for type coordinate nodes.</td>
    </tr>
    <tr>
      <td><code>{"MEMBER_COORDINATE"}</code></td>
      <td><code>{"\"MemberCoordinate\""}</code></td>
      <td>AST kind for member coordinate nodes.</td>
    </tr>
    <tr>
      <td><code>{"ARGUMENT_COORDINATE"}</code></td>
      <td><code>{"\"ArgumentCoordinate\""}</code></td>
      <td>AST kind for argument coordinate nodes.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE_COORDINATE"}</code></td>
      <td><code>{"\"DirectiveCoordinate\""}</code></td>
      <td>AST kind for directive coordinate nodes.</td>
    </tr>
    <tr>
      <td><code>{"DIRECTIVE_ARGUMENT_COORDINATE"}</code></td>
      <td><code>{"\"DirectiveArgumentCoordinate\""}</code></td>
      <td>AST kind for directive argument coordinate nodes.</td>
    </tr>
  </tbody>
</table>

### Types

#### DirectiveLocationEnum <span aria-label="Deprecated" className="api-tag" title="Deprecated">Deprecated</span>

**Type alias.** Deprecated legacy alias for the enum type representing directive location
values. This alias will be removed in v17. In v17, [`DirectiveLocation`](/api-v16/language#directivelocation) is
exported as the single public symbol for both the runtime object and the
corresponding TypeScript type.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "DirectiveLocationEnum"], " = ", ["keyword", "typeof"], " ", ["link", "DirectiveLocation", "/api-v16/language#directivelocation"], ";"]} />

<hr className="api-item-divider" />

#### KindEnum <span aria-label="Deprecated" className="api-tag" title="Deprecated">Deprecated</span>

**Type alias.** Deprecated legacy alias for the enum type representing the possible kind
values of AST nodes. This alias will be removed in v17. In v17, [`Kind`](/api-v16/language#kind) is
exported as the single public symbol for both the runtime object and the
corresponding TypeScript type.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "KindEnum"], " = ", ["keyword", "typeof"], " ", ["link", "Kind", "/api-v16/language#kind"], ";"]} />

## Category: Lexing

<div className="api-category-toc">
  <p>
    <strong>Classes:</strong><br />
    <a href="/api-v16/language#lexer">Lexer</a>
  </p>
  <p>
    <strong>Enumerations:</strong><br />
    <a href="/api-v16/language#tokenkind">TokenKind</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#tokenkindenum">TokenKindEnum</a>
  </p>
</div>

### Classes

#### Lexer

Given a Source object, creates a Lexer for that source.
A Lexer is a stateful stream generator in that every time
it is advanced, it returns the next token in the Source. Assuming the
source lexes, the final Token emitted by the lexer will be of kind
EOF, after which the lexer will repeatedly return the same EOF token
whenever called.

<hr className="api-subsection-divider" />

##### Constructor

Creates a Lexer instance.

**Signature:**

<ApiSignature parts={[["keyword", "new"], " ", ["name", "Lexer"], "(", ["parameter", "source"], ": ", ["link", "Source", "/api-v16/language#source"], ");"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>Source document used to derive error locations.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### Members

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>Source document used to derive error locations.</td>
    </tr>
    <tr>
      <td>lastToken</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>Most recent non-ignored token returned by the lexer.</td>
    </tr>
    <tr>
      <td>token</td>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>Current non-ignored token at the lexer cursor.</td>
    </tr>
    <tr>
      <td>line</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The (1-indexed) line containing the current token.</td>
    </tr>
    <tr>
      <td>lineStart</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>Character offset where the current line starts.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### advance()

Advances the token stream to the next non-ignored token.

**Signature:**

<ApiSignature parts={[["name", "advance"], "(): ", ["link", "Token", "/api-v16/language#token"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The next non-ignored token.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Lexer, Source } from 'graphql/language';

const lexer = new Lexer(new Source('{ hello }'));
const token = lexer.advance();

token.kind; // => '{'
lexer.token; // => token
```

<hr className="api-subsection-divider" />

##### lookahead()

Looks ahead and returns the next non-ignored token, but does not change
the state of Lexer.

**Signature:**

<ApiSignature parts={[["name", "lookahead"], "(): ", ["link", "Token", "/api-v16/language#token"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "Token", "/api-v16/language#token"]]} /></td>
      <td>The next non-ignored token without advancing the lexer.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Lexer, Source } from 'graphql/language';

const lexer = new Lexer(new Source('{ hello }'));
const token = lexer.lookahead();

token.kind; // => '{'
lexer.token.kind; // => '<SOF>'
```

### Enumerations

#### TokenKind

**Enumeration.** An exported enum describing the different kinds of tokens that the
lexer emits.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Value</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><code>{"SOF"}</code></td>
      <td><code>{"\"<SOF>\""}</code></td>
      <td>Start-of-file token.</td>
    </tr>
    <tr>
      <td><code>{"EOF"}</code></td>
      <td><code>{"\"<EOF>\""}</code></td>
      <td>End-of-file token.</td>
    </tr>
    <tr>
      <td><code>{"BANG"}</code></td>
      <td><code>{"\"!\""}</code></td>
      <td>The <code>{"!"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"DOLLAR"}</code></td>
      <td><code>{"\"$\""}</code></td>
      <td>The <code>{"$"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"AMP"}</code></td>
      <td><code>{"\"&\""}</code></td>
      <td>The <code>{"&"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"PAREN_L"}</code></td>
      <td><code>{"\"(\""}</code></td>
      <td>The <code>{"("}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"PAREN_R"}</code></td>
      <td><code>{"\")\""}</code></td>
      <td>The <code>{")"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"DOT"}</code></td>
      <td><code>{"\".\""}</code></td>
      <td>The <code>{"."}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"SPREAD"}</code></td>
      <td><code>{"\"...\""}</code></td>
      <td>The <code>{"..."}</code> spread punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"COLON"}</code></td>
      <td><code>{"\":\""}</code></td>
      <td>The <code>{":"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"EQUALS"}</code></td>
      <td><code>{"\"=\""}</code></td>
      <td>The <code>{"="}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"AT"}</code></td>
      <td><code>{"\"@\""}</code></td>
      <td>The <code>{"@"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"BRACKET_L"}</code></td>
      <td><code>{"\"[\""}</code></td>
      <td>The <code>{"["}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"BRACKET_R"}</code></td>
      <td><code>{"\"]\""}</code></td>
      <td>The <code>{"]"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"BRACE_L"}</code></td>
      <td><code>{"\"{\""}</code></td>
      <td>The <code>{"{"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"PIPE"}</code></td>
      <td><code>{"\"\u007c\""}</code></td>
      <td>The <code>{"\u007c"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"BRACE_R"}</code></td>
      <td><code>{"\"}\""}</code></td>
      <td>The <code>{"}"}</code> punctuation token.</td>
    </tr>
    <tr>
      <td><code>{"NAME"}</code></td>
      <td><code>{"\"Name\""}</code></td>
      <td>A GraphQL name token or name AST node.</td>
    </tr>
    <tr>
      <td><code>{"INT"}</code></td>
      <td><code>{"\"Int\""}</code></td>
      <td>An integer value token or AST node.</td>
    </tr>
    <tr>
      <td><code>{"FLOAT"}</code></td>
      <td><code>{"\"Float\""}</code></td>
      <td>A floating-point value token or AST node.</td>
    </tr>
    <tr>
      <td><code>{"STRING"}</code></td>
      <td><code>{"\"String\""}</code></td>
      <td>A string value token or AST node.</td>
    </tr>
    <tr>
      <td><code>{"BLOCK_STRING"}</code></td>
      <td><code>{"\"BlockString\""}</code></td>
      <td>A block string value token.</td>
    </tr>
    <tr>
      <td><code>{"COMMENT"}</code></td>
      <td><code>{"\"Comment\""}</code></td>
      <td>A comment token.</td>
    </tr>
  </tbody>
</table>

### Types

#### TokenKindEnum <span aria-label="Deprecated" className="api-tag" title="Deprecated">Deprecated</span>

**Type alias.** Deprecated legacy alias for the enum type representing token kind values.
This alias will be removed in v17. In v17, [`TokenKind`](/api-v16/language#tokenkind) is exported as the
single public symbol for both the runtime object and the corresponding
TypeScript type.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "TokenKindEnum"], " = ", ["keyword", "typeof"], " ", ["link", "TokenKind", "/api-v16/language#tokenkind"], ";"]} />

## Category: Source

<div className="api-category-toc">
  <p>
    <strong>Classes:</strong><br />
    <a href="/api-v16/language#source">Source</a>
  </p>
  <p>
    <strong>Functions:</strong><br />
    <a href="/api-v16/language#getlocation">getLocation()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#printlocation">printLocation()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#printsourcelocation">printSourceLocation()</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#sourcelocation">SourceLocation</a>
  </p>
</div>

### Classes

#### Source

A representation of source input to GraphQL. The `name` and `locationOffset` parameters are
optional, but they are useful for clients who store GraphQL documents in source files.
For example, if the GraphQL input starts at line 40 in a file named `Foo.graphql`, it might
be useful for `name` to be `"Foo.graphql"` and location to be `{ line: 40, column: 1 }`.
The `line` and `column` properties in `locationOffset` are 1-indexed.

<hr className="api-subsection-divider" />

##### Constructor

Creates a Source instance.

**Signature:**

<ApiSignature parts={[["keyword", "new"], " ", ["name", "Source"], "(\n  ", ["parameter", "body"], ": ", ["keyword", "string"], ",\n  ", ["parameter", "name"], ": ", ["keyword", "string"], " = ", ["literal", "'GraphQL request'"], ",\n  ", ["parameter", "locationOffset"], ": \u007b\n    ", ["property", "line"], ": ", ["keyword", "number"], ";\n    ", ["property", "column"], ": ", ["keyword", "number"], ";\n  \u007d = \u007b line: ", ["literal", "1"], ", column: ", ["literal", "1"], " \u007d,\n);"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Default</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>body</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td></td>
      <td>The GraphQL source text.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td><ApiType parts={[["literal", "'GraphQL request'"]]} /></td>
      <td>Name used in diagnostics for this source.</td>
    </tr>
    <tr>
      <td>locationOffset</td>
      <td><ApiType parts={["\u007b ", ["property", "line"], ": ", ["keyword", "number"], "; ", ["property", "column"], ": ", ["keyword", "number"], " \u007d"]} /></td>
      <td><ApiType parts={["\u007b line: ", ["literal", "1"], ", column: ", ["literal", "1"], " \u007d"]} /></td>
      <td>One-indexed line and column where this source begins.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

##### Members

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>body</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>The GraphQL source text.</td>
    </tr>
    <tr>
      <td>name</td>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>Name used in diagnostics for this source, such as a file path or request name.</td>
    </tr>
    <tr>
      <td>locationOffset</td>
      <td><ApiType parts={["\u007b ", ["property", "line"], ": ", ["keyword", "number"], "; ", ["property", "column"], ": ", ["keyword", "number"], " \u007d"]} /></td>
      <td>One-indexed line and column where this source begins.</td>
    </tr>
  </tbody>
</table>

### Functions

#### getLocation()

Takes a Source and a UTF-8 character offset, and returns the corresponding
line and column as a SourceLocation.

**Signature:**

<ApiSignature parts={[["name", "getLocation"], "(\n  ", ["parameter", "source"], ": ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "position"], ": ", ["keyword", "number"], ",\n): ", ["link", "SourceLocation", "/api-v16/language#sourcelocation"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>The source document that contains the position.</td>
    </tr>
    <tr>
      <td>position</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>The UTF-8 character offset in the source body.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "SourceLocation", "/api-v16/language#sourcelocation"]]} /></td>
      <td>The 1-indexed line and column for the given source position.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Source, getLocation } from 'graphql/language';

const source = new Source('type Query { hello: String }');
const location = getLocation(source, 13);

location; // => { line: 1, column: 14 }
```

<hr className="api-item-divider" />

#### printLocation()

Render a helpful description of the location in the GraphQL Source document.

**Signature:**

<ApiSignature parts={[["name", "printLocation"], "(", ["parameter", "location"], ": ", ["link", "Location", "/api-v16/language#location"], "): ", ["keyword", "string"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>location</td>
      <td><ApiType parts={[["link", "Location", "/api-v16/language#location"]]} /></td>
      <td>The AST location to print.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>A formatted source excerpt with line and column information.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, printLocation } from 'graphql/language';

const document = parse('type Query { hello: String }');
const location = document.definitions[0].loc;

if (location) {
  const printed = printLocation(location);

  printed; // => 'GraphQL request:1:1\n1 | type Query { hello: String }\n  | ^'
}
```

<hr className="api-item-divider" />

#### printSourceLocation()

Render a helpful description of the location in the GraphQL Source document.

**Signature:**

<ApiSignature parts={[["name", "printSourceLocation"], "(\n  ", ["parameter", "source"], ": ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "sourceLocation"], ": ", ["link", "SourceLocation", "/api-v16/language#sourcelocation"], ",\n): ", ["keyword", "string"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>The source document that contains the location.</td>
    </tr>
    <tr>
      <td>sourceLocation</td>
      <td><ApiType parts={[["link", "SourceLocation", "/api-v16/language#sourcelocation"]]} /></td>
      <td>The 1-indexed line and column to print.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>A formatted source excerpt with line and column information.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Source, printSourceLocation } from 'graphql/language';

const source = new Source('type Query { hello: String }');
const printed = printSourceLocation(source, { line: 1, column: 14 });

printed; // => 'GraphQL request:1:14\n1 | type Query { hello: String }\n  |              ^'
```

### Types

#### SourceLocation

**Interface.** Represents a location in a Source.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>line</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>One-indexed line number in the source document.</td>
    </tr>
    <tr>
      <td>column</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>One-indexed column number in the source document.</td>
    </tr>
  </tbody>
</table>

## Category: Parsing

<div className="api-category-toc">
  <p>
    <strong>Functions:</strong><br />
    <a href="/api-v16/language#parse">parse()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#parsevalue">parseValue()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#parseconstvalue">parseConstValue()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#parsetype">parseType()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#parseschemacoordinate">parseSchemaCoordinate()</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#parseoptions">ParseOptions</a>
  </p>
</div>

### Functions

#### parse()

Given a GraphQL source, parses it into a Document.
Throws GraphQLError if a syntax error is encountered.

**Signature:**

<ApiSignature parts={[["name", "parse"], "(\n  ", ["parameter", "source"], ": ", ["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "options"], "?: ", ["link", "ParseOptions", "/api-v16/language#parseoptions"], ",\n): ", ["link", "DocumentNode", "/api-v16/language#documentnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>A GraphQL source string or source object.</td>
    </tr>
    <tr>
      <td>options?</td>
      <td><ApiType parts={[["link", "ParseOptions", "/api-v16/language#parseoptions"]]} /></td>
      <td>Optional parser configuration.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "DocumentNode", "/api-v16/language#documentnode"]]} /></td>
      <td>The parsed GraphQL document AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example 1</div>

```ts
// Parse a GraphQL document with the default parser options.
import { parse } from 'graphql/language';

const document = parse('{ hero { name } }');

document.kind; // => 'Document'
```

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example 2</div>

```ts
// This variant enables parser options and provides an explicit lexer.
import { Lexer, Source, parse } from 'graphql/language';

const document = parse('fragment A($var: Boolean) on Query { field }', {
  allowLegacyFragmentVariables: true,
  maxTokens: 20,
  noLocation: true,
});
const directiveDocument = parse('directive @foo @bar on FIELD', {
  experimentalDirectivesOnDirectiveDefinitions: true,
});
const source = new Source('{ hero }');
const lexerDocument = parse(source, { lexer: new Lexer(source) });

document.definitions[0].kind; // => 'FragmentDefinition'
document.loc; // => undefined
directiveDocument.definitions[0].kind; // => 'DirectiveDefinition'
lexerDocument.definitions[0].kind; // => 'OperationDefinition'
```

<hr className="api-item-divider" />

#### parseValue()

Given a string containing a GraphQL value (ex. `[42]`), parse the AST for
that value.
Throws GraphQLError if a syntax error is encountered.

This is useful within tools that operate upon GraphQL Values directly and
in isolation of complete GraphQL documents.

Consider providing the results to the utility function: valueFromAST().

**Signature:**

<ApiSignature parts={[["name", "parseValue"], "(\n  ", ["parameter", "source"], ": ", ["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "options"], "?: ", ["link", "ParseOptions", "/api-v16/language#parseoptions"], ",\n): ", ["link", "ValueNode", "/api-v16/language#valuenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>A GraphQL source string or source object containing a value.</td>
    </tr>
    <tr>
      <td>options?</td>
      <td><ApiType parts={[["link", "ParseOptions", "/api-v16/language#parseoptions"]]} /></td>
      <td>Optional parser configuration.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "ValueNode", "/api-v16/language#valuenode"]]} /></td>
      <td>The parsed GraphQL value AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseValue } from 'graphql/language';

const value = parseValue('[42]');

value.kind; // => 'ListValue'
```

<hr className="api-item-divider" />

#### parseConstValue()

Similar to parseValue(), but raises a parse error if it encounters a
variable. The return type will be a constant value.

**Signature:**

<ApiSignature parts={[["name", "parseConstValue"], "(\n  ", ["parameter", "source"], ": ", ["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "options"], "?: ", ["link", "ParseOptions", "/api-v16/language#parseoptions"], ",\n): ", ["link", "ConstValueNode", "/api-v16/language#constvaluenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>A GraphQL source string or source object containing a constant value.</td>
    </tr>
    <tr>
      <td>options?</td>
      <td><ApiType parts={[["link", "ParseOptions", "/api-v16/language#parseoptions"]]} /></td>
      <td>Optional parser configuration.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>The parsed GraphQL constant value AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseConstValue } from 'graphql/language';

const value = parseConstValue('{ enabled: true }');

value.kind; // => 'ObjectValue'
parseConstValue('$variable'); // throws an error
```

<hr className="api-item-divider" />

#### parseType()

Given a string containing a GraphQL Type (ex. `[Int!]`), parse the AST for
that type.
Throws GraphQLError if a syntax error is encountered.

This is useful within tools that operate upon GraphQL Types directly and
in isolation of complete GraphQL documents.

Consider providing the results to the utility function: typeFromAST().

**Signature:**

<ApiSignature parts={[["name", "parseType"], "(\n  ", ["parameter", "source"], ": ", ["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"], ",\n  ", ["parameter", "options"], "?: ", ["link", "ParseOptions", "/api-v16/language#parseoptions"], ",\n): ", ["link", "TypeNode", "/api-v16/language#typenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>A GraphQL source string or source object containing a type reference.</td>
    </tr>
    <tr>
      <td>options?</td>
      <td><ApiType parts={[["link", "ParseOptions", "/api-v16/language#parseoptions"]]} /></td>
      <td>Optional parser configuration.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>The parsed GraphQL type AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseType } from 'graphql/language';

const type = parseType('[String!]');

type.kind; // => 'ListType'
```

<hr className="api-item-divider" />

#### parseSchemaCoordinate()

Given a string containing a GraphQL Schema Coordinate (ex. `Type.field`),
parse the AST for that schema coordinate.
Throws GraphQLError if a syntax error is encountered.

Consider providing the results to the utility function:
resolveASTSchemaCoordinate(). Or calling resolveSchemaCoordinate() directly
with an unparsed source.

**Signature:**

<ApiSignature parts={[["name", "parseSchemaCoordinate"], "(\n  ", ["parameter", "source"], ": ", ["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"], ",\n): ", ["link", "SchemaCoordinateNode", "/api-v16/language#schemacoordinatenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>source</td>
      <td><ApiType parts={[["keyword", "string"], " \u007c ", ["link", "Source", "/api-v16/language#source"]]} /></td>
      <td>A GraphQL source string or source object containing a schema coordinate.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "SchemaCoordinateNode", "/api-v16/language#schemacoordinatenode"]]} /></td>
      <td>The parsed GraphQL schema coordinate AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseSchemaCoordinate } from 'graphql/language';

const coordinate = parseSchemaCoordinate('Query.hero');

coordinate.kind; // => 'MemberCoordinate'
```

### Types

#### ParseOptions

**Interface.** Configuration options to control parser behavior

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Members</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>noLocation?</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>By default, the parser creates AST nodes that know the location<br />
in the source that they correspond to. This configuration flag<br />
disables that behavior for performance or testing.</td>
    </tr>
    <tr>
      <td>maxTokens?</td>
      <td><ApiType parts={[["keyword", "number"]]} /></td>
      <td>Parser CPU and memory usage is linear to the number of tokens in a document<br />
however in extreme cases it becomes quadratic due to memory exhaustion.<br />
Parsing happens before validation so even invalid queries can burn lots of<br />
CPU time and memory.<br />
To prevent this you can set a maximum number of tokens allowed within a document.</td>
    </tr>
    <tr>
      <td>allowLegacyFragmentVariables?</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>Deprecated option that allows legacy fragment variable definitions to be<br />
parsed. This legacy fragment variable syntax will be removed in v17. Move<br />
variable definitions to operations for spec-compliant documents; if you<br />
need variables or arguments scoped to fragments, v17 has a more complete<br />
experimental fragment-arguments feature.</td>
    </tr>
    <tr>
      <td>experimentalDirectivesOnDirectiveDefinitions?</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>EXPERIMENTAL:<br />
If enabled, the parser will parse directives on directive definitions.<br />
This syntax is not part of the GraphQL specification and may change.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">allowLegacyFragmentVariables Example</div>

The syntax is identical to normal, query-defined variables.

```graphql
fragment A($var: Boolean = false) on T {
  ...
}
```

<hr className="api-subsection-divider" />

<div className="api-subsection-title">experimentalDirectivesOnDirectiveDefinitions Example</div>

```graphql
directive @foo @bar on FIELD
```

## Category: AST Predicates

<div className="api-category-toc">
  <p>
    <strong>Functions:</strong><br />
    <a href="/api-v16/language#isdefinitionnode">isDefinitionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#isexecutabledefinitionnode">isExecutableDefinitionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#isselectionnode">isSelectionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#isvaluenode">isValueNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#isconstvaluenode">isConstValueNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#istypenode">isTypeNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#istypesystemdefinitionnode">isTypeSystemDefinitionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#istypedefinitionnode">isTypeDefinitionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#istypesystemextensionnode">isTypeSystemExtensionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#istypeextensionnode">isTypeExtensionNode()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#isschemacoordinatenode">isSchemaCoordinateNode()</a>
  </p>
</div>

### Functions

#### isDefinitionNode()

Returns true when the AST node is a definition node.

**Signature:**

<ApiSignature parts={[["name", "isDefinitionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "DefinitionNode", "/api-v16/language#definitionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "DefinitionNode", "/api-v16/language#definitionnode"]]} /></td>
      <td>True when the AST node is a definition node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isDefinitionNode } from 'graphql/language';

const document = parse('{ hello }');

isDefinitionNode(document.definitions[0]); // => true
isDefinitionNode(document); // => false
```

<hr className="api-item-divider" />

#### isExecutableDefinitionNode()

Returns true when the AST node is an executable definition node.

**Signature:**

<ApiSignature parts={[["name", "isExecutableDefinitionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ExecutableDefinitionNode", "/api-v16/language#executabledefinitionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ExecutableDefinitionNode", "/api-v16/language#executabledefinitionnode"]]} /></td>
      <td>True when the AST node is an executable definition node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isExecutableDefinitionNode } from 'graphql/language';

const query = parse('{ hello }');
const schema = parse('type Query { hello: String }');

isExecutableDefinitionNode(query.definitions[0]); // => true
isExecutableDefinitionNode(schema.definitions[0]); // => false
```

<hr className="api-item-divider" />

#### isSelectionNode()

Returns true when the AST node is a selection node.

**Signature:**

<ApiSignature parts={[["name", "isSelectionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "SelectionNode", "/api-v16/language#selectionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "SelectionNode", "/api-v16/language#selectionnode"]]} /></td>
      <td>True when the AST node is a selection node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Kind, isSelectionNode } from 'graphql/language';

const field = { kind: Kind.FIELD, name: { kind: Kind.NAME, value: 'hello' } };
const document = { kind: Kind.DOCUMENT, definitions: [] };

isSelectionNode(field); // => true
isSelectionNode(document); // => false
```

<hr className="api-item-divider" />

#### isValueNode()

Returns true when the AST node is a value node.

**Signature:**

<ApiSignature parts={[["name", "isValueNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ValueNode", "/api-v16/language#valuenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ValueNode", "/api-v16/language#valuenode"]]} /></td>
      <td>True when the AST node is a value node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseType, parseValue, isValueNode } from 'graphql/language';

const value = parseValue('[42]');
const type = parseType('[String!]');

isValueNode(value); // => true
isValueNode(type); // => false
```

<hr className="api-item-divider" />

#### isConstValueNode()

Returns true when the AST node is a constant value node.

**Signature:**

<ApiSignature parts={[["name", "isConstValueNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ConstValueNode", "/api-v16/language#constvaluenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "ConstValueNode", "/api-v16/language#constvaluenode"]]} /></td>
      <td>True when the AST node is a constant value node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseConstValue, parseValue, isConstValueNode } from 'graphql/language';

const value = parseConstValue('[42]');
const variable = parseValue('$id');

isConstValueNode(value); // => true
isConstValueNode(variable); // => false
```

<hr className="api-item-divider" />

#### isTypeNode()

Returns true when the AST node is a type node.

**Signature:**

<ApiSignature parts={[["name", "isTypeNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeNode", "/api-v16/language#typenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeNode", "/api-v16/language#typenode"]]} /></td>
      <td>True when the AST node is a type node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parseType, parseValue, isTypeNode } from 'graphql/language';

const type = parseType('[String!]');
const value = parseValue('[42]');

isTypeNode(type); // => true
isTypeNode(value); // => false
```

<hr className="api-item-divider" />

#### isTypeSystemDefinitionNode()

Returns true when the AST node is a type system definition node.

**Signature:**

<ApiSignature parts={[["name", "isTypeSystemDefinitionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeSystemDefinitionNode", "/api-v16/language#typesystemdefinitionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeSystemDefinitionNode", "/api-v16/language#typesystemdefinitionnode"]]} /></td>
      <td>True when the AST node is a type system definition node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isTypeSystemDefinitionNode } from 'graphql/language';

const schema = parse('type Query { hello: String }');
const query = parse('{ hello }');

isTypeSystemDefinitionNode(schema.definitions[0]); // => true
isTypeSystemDefinitionNode(query.definitions[0]); // => false
```

<hr className="api-item-divider" />

#### isTypeDefinitionNode()

Returns true when the AST node is a type definition node.

**Signature:**

<ApiSignature parts={[["name", "isTypeDefinitionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeDefinitionNode", "/api-v16/language#typedefinitionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeDefinitionNode", "/api-v16/language#typedefinitionnode"]]} /></td>
      <td>True when the AST node is a type definition node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isTypeDefinitionNode } from 'graphql/language';

const typeDefinition = parse('type Query { hello: String }');
const directiveDefinition = parse('directive @cache on FIELD');

isTypeDefinitionNode(typeDefinition.definitions[0]); // => true
isTypeDefinitionNode(directiveDefinition.definitions[0]); // => false
```

<hr className="api-item-divider" />

#### isTypeSystemExtensionNode()

Returns true when the AST node is a type system extension node.

**Signature:**

<ApiSignature parts={[["name", "isTypeSystemExtensionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeSystemExtensionNode", "/api-v16/language#typesystemextensionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeSystemExtensionNode", "/api-v16/language#typesystemextensionnode"]]} /></td>
      <td>True when the AST node is a type system extension node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isTypeSystemExtensionNode } from 'graphql/language';

const extension = parse('extend type Query { hello: String }');
const definition = parse('type Query { hello: String }');

isTypeSystemExtensionNode(extension.definitions[0]); // => true
isTypeSystemExtensionNode(definition.definitions[0]); // => false
```

<hr className="api-item-divider" />

#### isTypeExtensionNode()

Returns true when the AST node is a type extension node.

**Signature:**

<ApiSignature parts={[["name", "isTypeExtensionNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeExtensionNode", "/api-v16/language#typeextensionnode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "TypeExtensionNode", "/api-v16/language#typeextensionnode"]]} /></td>
      <td>True when the AST node is a type extension node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, isTypeExtensionNode } from 'graphql/language';

const extension = parse('extend type Query { hello: String }');
const schemaExtension = parse('extend schema { query: Query }');

isTypeExtensionNode(extension.definitions[0]); // => true
isTypeExtensionNode(schemaExtension.definitions[0]); // => false
```

<hr className="api-item-divider" />

#### isSchemaCoordinateNode()

Returns true when the AST node is a schema coordinate node.

**Signature:**

<ApiSignature parts={[["name", "isSchemaCoordinateNode"], "(\n  ", ["parameter", "node"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], ",\n): ", ["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "SchemaCoordinateNode", "/api-v16/language#schemacoordinatenode"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>node</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The AST node to test.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["parameter", "node"], " ", ["keyword", "is"], " ", ["link", "SchemaCoordinateNode", "/api-v16/language#schemacoordinatenode"]]} /></td>
      <td>True when the AST node is a schema coordinate node.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import {
  parse,
  parseSchemaCoordinate,
  isSchemaCoordinateNode,
} from 'graphql/language';

const coordinate = parseSchemaCoordinate('Query.hero');
const document = parse('{ hero }');

isSchemaCoordinateNode(coordinate); // => true
isSchemaCoordinateNode(document); // => false
```

## Category: Printing

<div className="api-category-toc">
  <p>
    <strong>Functions:</strong><br />
    <a href="/api-v16/language#print">print()</a>
  </p>
</div>

### Functions

#### print()

Converts an AST into a string, using one set of reasonable
formatting rules.

**Signature:**

<ApiSignature parts={[["name", "print"], "(", ["parameter", "ast"], ": ", ["link", "ASTNode", "/api-v16/language#astnode"], "): ", ["keyword", "string"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>ast</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td>The GraphQL AST node to print.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["keyword", "string"]]} /></td>
      <td>A stable string representation of the AST.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, print } from 'graphql';

const ast = parse('{ hero { name } }');
const text = print(ast);

text; // => '{\n  hero {\n    name\n  }\n}'
```

## Category: Visiting

<div className="api-category-toc">
  <p>
    <strong>Functions:</strong><br />
    <a href="/api-v16/language#visitinparallel">visitInParallel()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#getenterleaveforkind">getEnterLeaveForKind()</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#getvisitfn">getVisitFn()</a>
  </p>
  <p>
    <strong>Constants:</strong><br />
    <a href="/api-v16/language#break">BREAK</a>
  </p>
  <p>
    <strong>Types:</strong><br />
    <a href="/api-v16/language#astvisitor">ASTVisitor</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#astvisitfn">ASTVisitFn</a>
    <span aria-hidden="true">&middot;</span>
    <a href="/api-v16/language#astvisitorkeymap">ASTVisitorKeyMap</a>
  </p>
</div>

### Functions

#### visitInParallel()

Creates a new visitor instance which delegates to many visitors to run in
parallel. Each visitor will be visited for each node before moving on.

If a prior visitor edits a node, no following visitors will see that node.

**Signature:**

<ApiSignature parts={[["name", "visitInParallel"], "(\n  ", ["parameter", "visitors"], ": ", ["keyword", "readonly"], " ", ["link", "ASTVisitor", "/api-v16/language#astvisitor"], "[],\n): ", ["link", "ASTVisitor", "/api-v16/language#astvisitor"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>visitors</td>
      <td><ApiType parts={[["keyword", "readonly"], " ", ["link", "ASTVisitor", "/api-v16/language#astvisitor"], "[]"]} /></td>
      <td>The visitors to merge into one parallel visitor.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "ASTVisitor", "/api-v16/language#astvisitor"]]} /></td>
      <td>A visitor that delegates traversal to each provided visitor.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { parse, visit, visitInParallel } from 'graphql/language';

const document = parse('{ hero { name } }');
const events = [];

visit(
  document,
  visitInParallel([
    { Field: (node) => { events.push(`field:${node.name.value}`); } },
    { Name: (node) => { events.push(`name:${node.value}`); } },
  ]),
);

events; // => ['field:hero', 'name:hero', 'field:name', 'name:name']
```

<hr className="api-item-divider" />

#### getEnterLeaveForKind()

Given a visitor instance and a node kind, return EnterLeaveVisitor for that kind.

**Signature:**

<ApiSignature parts={[["name", "getEnterLeaveForKind"], "(\n  ", ["parameter", "visitor"], ": ", ["link", "ASTVisitor", "/api-v16/language#astvisitor"], ",\n  ", ["parameter", "kind"], ": ", ["link", "Kind", "/api-v16/language#kind"], ",\n): \u007b\n  ", ["property", "enter"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n  ", ["property", "leave"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n\u007d;"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>visitor</td>
      <td><ApiType parts={[["link", "ASTVisitor", "/api-v16/language#astvisitor"]]} /></td>
      <td>The visitor object to inspect.</td>
    </tr>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "Kind", "/api-v16/language#kind"]]} /></td>
      <td>The AST node kind to resolve handlers for.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={["\u007b\n  ", ["property", "enter"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n  ", ["property", "leave"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n\u007d"]} /></td>
      <td>The enter and leave handlers that apply for the given node kind.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Kind, getEnterLeaveForKind } from 'graphql/language';

const handlers = getEnterLeaveForKind({ Field: () => {} }, Kind.FIELD);

typeof handlers.enter; // => 'function'
handlers.leave; // => undefined
```

<hr className="api-item-divider" />

#### getVisitFn() <span aria-label="Deprecated" className="api-tag" title="Deprecated">Deprecated</span>

Given a visitor instance, if it is leaving or not, and a node kind, return
the function the visitor runtime should call. This deprecated compatibility
helper delegates to [`getEnterLeaveForKind`](/api-v16/language#getenterleaveforkind); call [`getEnterLeaveForKind`](/api-v16/language#getenterleaveforkind)
directly because getVisitFn will be removed in v17.

**Signature:**

<ApiSignature parts={[["name", "getVisitFn"], "(\n  ", ["parameter", "visitor"], ": ", ["link", "ASTVisitor", "/api-v16/language#astvisitor"], ",\n  ", ["parameter", "kind"], ": ", ["link", "Kind", "/api-v16/language#kind"], ",\n  ", ["parameter", "isLeaving"], ": ", ["keyword", "boolean"], ",\n): ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e \u007c ", ["keyword", "undefined"], ";"]} />

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Arguments</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>visitor</td>
      <td><ApiType parts={[["link", "ASTVisitor", "/api-v16/language#astvisitor"]]} /></td>
      <td>The visitor object to inspect.</td>
    </tr>
    <tr>
      <td>kind</td>
      <td><ApiType parts={[["link", "Kind", "/api-v16/language#kind"]]} /></td>
      <td>The AST node kind to resolve a handler for.</td>
    </tr>
    <tr>
      <td>isLeaving</td>
      <td><ApiType parts={[["keyword", "boolean"]]} /></td>
      <td>Whether to resolve the leave handler instead of the enter handler.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Returns</div>

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td><ApiType parts={[["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e \u007c ", ["keyword", "undefined"]]} /></td>
      <td>The visit function that applies for the given node kind and traversal phase, if one exists.</td>
    </tr>
  </tbody>
</table>

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Example</div>

```ts
import { Kind, getVisitFn } from 'graphql/language';

const enter = getVisitFn({ Field: () => {} }, Kind.FIELD, false);
const leave = getVisitFn({ Field: () => {} }, Kind.FIELD, true);

typeof enter; // => 'function'
leave; // => undefined
```

### Constants

#### BREAK

A value that can be returned from a visitor function to stop traversal.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Type</div>

<ApiType parts={[["keyword", "unknown"]]} />

### Types

#### ASTVisitor

**Type alias.** A visitor defines the callbacks called during AST traversal.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ASTVisitor"], " =\n  \u007c \u007b\n      ", ["property", "enter"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n      ", ["property", "leave"], "?: ", ["link", "ASTVisitFn", "/api-v16/language#astvisitfn"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e;\n    \u007d\n  \u007c \u007b\n      ", ["keyword", "readonly"], " [NodeT ", ["keyword", "in"], " ASTNode ", ["keyword", "as"], " NodeT[", ["literal", "'kind'"], "]]?:\n        \u007c ASTVisitFn\u003cNodeT\u003e\n        \u007c EnterLeaveVisitor\u003cNodeT\u003e;\n    \u007d;"]} />

<hr className="api-item-divider" />

#### ASTVisitFn

**Type alias.** A visitor is composed of visit functions called for each node during traversal.

<hr className="api-subsection-divider" />

<div className="api-subsection-title">Type Parameters</div>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Constraint</th>
      <th>Default</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>TVisitedNode</td>
      <td><ApiType parts={[["link", "ASTNode", "/api-v16/language#astnode"]]} /></td>
      <td></td>
      <td>AST node type handled by this visitor function.</td>
    </tr>
  </tbody>
</table>

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ASTVisitFn"], "\u003c", ["type", "TVisitedNode"], " ", ["keyword", "extends"], " ", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e = (\n  ", ["parameter", "node"], ": ", ["type", "TVisitedNode"], ",\n  ", ["parameter", "key"], ": ", ["keyword", "string"], " \u007c ", ["keyword", "number"], " \u007c ", ["keyword", "undefined"], ",\n  ", ["parameter", "parent"], ":\n    \u007c ", ["link", "ASTNode", "/api-v16/language#astnode"], "\n    \u007c ", ["type", "ReadonlyArray"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e\n    \u007c ", ["keyword", "undefined"], ",\n  ", ["parameter", "path"], ": ", ["type", "ReadonlyArray"], "\u003c", ["keyword", "string"], " \u007c ", ["keyword", "number"], "\u003e,\n  ", ["parameter", "ancestors"], ": ", ["type", "ReadonlyArray"], "\u003c\n    ", ["link", "ASTNode", "/api-v16/language#astnode"], " \u007c ", ["type", "ReadonlyArray"], "\u003c", ["link", "ASTNode", "/api-v16/language#astnode"], "\u003e\n  \u003e,\n) =\u003e ", ["keyword", "any"], ";"]} />

<hr className="api-item-divider" />

#### ASTVisitorKeyMap <span aria-label="Deprecated" className="api-tag" title="Deprecated">Deprecated</span>

**Type alias.** Deprecated visitor key map type retained for compatibility. Inline this
mapped type at use sites because ASTVisitorKeyMap will be removed in v17.

<ApiSignature parts={[["keyword", "type"], " ", ["name", "ASTVisitorKeyMap"], " = ", ["type", "mapped object"], ";"]} />