1205 lines
44 KiB
Python
1205 lines
44 KiB
Python
from functools import partial
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from typing import Callable, Dict, List, Optional, TypeVar, Union, cast
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from ..error import GraphQLError, GraphQLSyntaxError
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from .ast import (
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ArgumentNode,
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BooleanValueNode,
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ConstArgumentNode,
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ConstDirectiveNode,
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ConstValueNode,
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DefinitionNode,
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DirectiveDefinitionNode,
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DirectiveNode,
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DocumentNode,
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EnumTypeDefinitionNode,
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EnumTypeExtensionNode,
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EnumValueDefinitionNode,
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EnumValueNode,
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FieldDefinitionNode,
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FieldNode,
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FloatValueNode,
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FragmentDefinitionNode,
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FragmentSpreadNode,
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InlineFragmentNode,
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InputObjectTypeDefinitionNode,
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InputObjectTypeExtensionNode,
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InputValueDefinitionNode,
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InterfaceTypeDefinitionNode,
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InterfaceTypeExtensionNode,
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IntValueNode,
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ListTypeNode,
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ListValueNode,
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Location,
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NamedTypeNode,
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NameNode,
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NonNullTypeNode,
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NullValueNode,
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ObjectFieldNode,
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ObjectTypeDefinitionNode,
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ObjectTypeExtensionNode,
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ObjectValueNode,
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OperationDefinitionNode,
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OperationType,
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OperationTypeDefinitionNode,
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ScalarTypeDefinitionNode,
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ScalarTypeExtensionNode,
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SchemaDefinitionNode,
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SchemaExtensionNode,
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SelectionNode,
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SelectionSetNode,
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StringValueNode,
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Token,
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TypeNode,
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TypeSystemExtensionNode,
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UnionTypeDefinitionNode,
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UnionTypeExtensionNode,
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ValueNode,
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VariableDefinitionNode,
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VariableNode,
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)
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from .directive_locations import DirectiveLocation
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from .lexer import Lexer, is_punctuator_token_kind
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from .source import Source, is_source
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from .token_kind import TokenKind
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__all__ = ["parse", "parse_type", "parse_value", "parse_const_value"]
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T = TypeVar("T")
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SourceType = Union[Source, str]
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def parse(
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source: SourceType,
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no_location: bool = False,
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max_tokens: Optional[int] = None,
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allow_legacy_fragment_variables: bool = False,
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) -> DocumentNode:
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"""Given a GraphQL source, parse it into a Document.
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Throws GraphQLError if a syntax error is encountered.
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By default, the parser creates AST nodes that know the location in the source that
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they correspond to. Setting the ``no_location`` parameter to False disables that
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behavior for performance or testing.
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Parser CPU and memory usage is linear to the number of tokens in a document,
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however in extreme cases it becomes quadratic due to memory exhaustion.
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Parsing happens before validation, so even invalid queries can burn lots of
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CPU time and memory. To prevent this, you can set a maximum number of tokens
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allowed within a document using the ``max_tokens`` parameter.
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Legacy feature (will be removed in v3.3):
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If ``allow_legacy_fragment_variables`` is set to ``True``, the parser will
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understand and parse variable definitions contained in a fragment definition.
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They'll be represented in the
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:attr:`~graphql.language.FragmentDefinitionNode.variable_definitions` field
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of the :class:`~graphql.language.FragmentDefinitionNode`.
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The syntax is identical to normal, query-defined variables. For example::
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fragment A($var: Boolean = false) on T {
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...
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}
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"""
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parser = Parser(
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source,
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no_location=no_location,
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max_tokens=max_tokens,
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allow_legacy_fragment_variables=allow_legacy_fragment_variables,
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)
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return parser.parse_document()
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def parse_value(
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source: SourceType,
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no_location: bool = False,
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max_tokens: Optional[int] = None,
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allow_legacy_fragment_variables: bool = False,
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) -> ValueNode:
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"""Parse the AST for a given string containing a GraphQL value.
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Throws GraphQLError if a syntax error is encountered.
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This is useful within tools that operate upon GraphQL Values directly and in
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isolation of complete GraphQL documents.
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Consider providing the results to the utility function:
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:func:`~graphql.utilities.value_from_ast`.
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"""
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parser = Parser(
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source,
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no_location=no_location,
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max_tokens=max_tokens,
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allow_legacy_fragment_variables=allow_legacy_fragment_variables,
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)
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parser.expect_token(TokenKind.SOF)
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value = parser.parse_value_literal(False)
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parser.expect_token(TokenKind.EOF)
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return value
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def parse_const_value(
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source: SourceType,
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no_location: bool = False,
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max_tokens: Optional[int] = None,
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allow_legacy_fragment_variables: bool = False,
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) -> ConstValueNode:
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"""Parse the AST for a given string containing a GraphQL constant value.
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Similar to parse_value, but raises a arse error if it encounters a variable.
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The return type will be a constant value.
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"""
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parser = Parser(
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source,
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no_location=no_location,
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max_tokens=max_tokens,
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allow_legacy_fragment_variables=allow_legacy_fragment_variables,
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)
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parser.expect_token(TokenKind.SOF)
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value = parser.parse_const_value_literal()
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parser.expect_token(TokenKind.EOF)
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return value
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def parse_type(
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source: SourceType,
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no_location: bool = False,
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max_tokens: Optional[int] = None,
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allow_legacy_fragment_variables: bool = False,
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) -> TypeNode:
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"""Parse the AST for a given string containing a GraphQL Type.
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Throws GraphQLError if a syntax error is encountered.
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This is useful within tools that operate upon GraphQL Types directly and
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in isolation of complete GraphQL documents.
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Consider providing the results to the utility function:
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:func:`~graphql.utilities.value_from_ast`.
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"""
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parser = Parser(
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source,
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no_location=no_location,
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max_tokens=max_tokens,
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allow_legacy_fragment_variables=allow_legacy_fragment_variables,
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)
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parser.expect_token(TokenKind.SOF)
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type_ = parser.parse_type_reference()
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parser.expect_token(TokenKind.EOF)
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return type_
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class Parser:
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"""GraphQL AST parser.
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This class is exported only to assist people in implementing their own parsers
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without duplicating too much code and should be used only as last resort for cases
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such as experimental syntax or if certain features couldn't be contributed upstream.
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It's still part of the internal API and is versioned, so any changes to it are never
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considered breaking changes. If you still need to support multiple versions of the
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library, please use the `__version_info__` variable for version detection.
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"""
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_lexer: Lexer
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_no_location: bool
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_max_tokens: Optional[int]
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_allow_legacy_fragment_variables: bool
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_token_counter: int
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def __init__(
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self,
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source: SourceType,
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no_location: bool = False,
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max_tokens: Optional[int] = None,
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allow_legacy_fragment_variables: bool = False,
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):
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source = (
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cast(Source, source) if is_source(source) else Source(cast(str, source))
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)
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self._lexer = Lexer(source)
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self._no_location = no_location
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self._max_tokens = max_tokens
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self._allow_legacy_fragment_variables = allow_legacy_fragment_variables
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self._token_counter = 0
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def parse_name(self) -> NameNode:
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"""Convert a name lex token into a name parse node."""
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token = self.expect_token(TokenKind.NAME)
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return NameNode(value=token.value, loc=self.loc(token))
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# Implement the parsing rules in the Document section.
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def parse_document(self) -> DocumentNode:
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"""Document: Definition+"""
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start = self._lexer.token
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return DocumentNode(
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definitions=self.many(TokenKind.SOF, self.parse_definition, TokenKind.EOF),
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loc=self.loc(start),
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)
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_parse_type_system_definition_method_names: Dict[str, str] = {
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"schema": "schema_definition",
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"scalar": "scalar_type_definition",
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"type": "object_type_definition",
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"interface": "interface_type_definition",
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"union": "union_type_definition",
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"enum": "enum_type_definition",
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"input": "input_object_type_definition",
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"directive": "directive_definition",
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}
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_parse_other_definition_method_names: Dict[str, str] = {
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**dict.fromkeys(("query", "mutation", "subscription"), "operation_definition"),
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"fragment": "fragment_definition",
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"extend": "type_system_extension",
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}
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def parse_definition(self) -> DefinitionNode:
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"""Definition: ExecutableDefinition or TypeSystemDefinition/Extension
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ExecutableDefinition: OperationDefinition or FragmentDefinition
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TypeSystemDefinition: SchemaDefinition, TypeDefinition or DirectiveDefinition
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TypeDefinition: ScalarTypeDefinition, ObjectTypeDefinition,
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InterfaceTypeDefinition, UnionTypeDefinition,
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EnumTypeDefinition or InputObjectTypeDefinition
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"""
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if self.peek(TokenKind.BRACE_L):
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return self.parse_operation_definition()
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# Many definitions begin with a description and require a lookahead.
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has_description = self.peek_description()
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keyword_token = (
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self._lexer.lookahead() if has_description else self._lexer.token
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)
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if keyword_token.kind is TokenKind.NAME:
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token_name = cast(str, keyword_token.value)
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method_name = self._parse_type_system_definition_method_names.get(
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token_name
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)
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if method_name:
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return getattr(self, f"parse_{method_name}")()
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if has_description:
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raise GraphQLSyntaxError(
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self._lexer.source,
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self._lexer.token.start,
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"Unexpected description,"
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" descriptions are supported only on type definitions.",
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)
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method_name = self._parse_other_definition_method_names.get(token_name)
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if method_name:
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return getattr(self, f"parse_{method_name}")()
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raise self.unexpected(keyword_token)
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# Implement the parsing rules in the Operations section.
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def parse_operation_definition(self) -> OperationDefinitionNode:
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"""OperationDefinition"""
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start = self._lexer.token
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if self.peek(TokenKind.BRACE_L):
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return OperationDefinitionNode(
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operation=OperationType.QUERY,
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name=None,
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variable_definitions=[],
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directives=[],
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selection_set=self.parse_selection_set(),
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loc=self.loc(start),
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)
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operation = self.parse_operation_type()
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name = self.parse_name() if self.peek(TokenKind.NAME) else None
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return OperationDefinitionNode(
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operation=operation,
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name=name,
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variable_definitions=self.parse_variable_definitions(),
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directives=self.parse_directives(False),
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selection_set=self.parse_selection_set(),
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loc=self.loc(start),
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)
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def parse_operation_type(self) -> OperationType:
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"""OperationType: one of query mutation subscription"""
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operation_token = self.expect_token(TokenKind.NAME)
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try:
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return OperationType(operation_token.value)
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except ValueError:
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raise self.unexpected(operation_token)
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def parse_variable_definitions(self) -> List[VariableDefinitionNode]:
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"""VariableDefinitions: (VariableDefinition+)"""
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return self.optional_many(
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TokenKind.PAREN_L, self.parse_variable_definition, TokenKind.PAREN_R
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)
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def parse_variable_definition(self) -> VariableDefinitionNode:
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"""VariableDefinition: Variable: Type DefaultValue? Directives[Const]?"""
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start = self._lexer.token
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return VariableDefinitionNode(
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variable=self.parse_variable(),
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type=self.expect_token(TokenKind.COLON) and self.parse_type_reference(),
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default_value=(
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self.parse_const_value_literal()
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if self.expect_optional_token(TokenKind.EQUALS)
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else None
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),
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directives=self.parse_const_directives(),
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loc=self.loc(start),
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)
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def parse_variable(self) -> VariableNode:
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"""Variable: $Name"""
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start = self._lexer.token
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self.expect_token(TokenKind.DOLLAR)
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return VariableNode(name=self.parse_name(), loc=self.loc(start))
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def parse_selection_set(self) -> SelectionSetNode:
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"""SelectionSet: {Selection+}"""
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start = self._lexer.token
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return SelectionSetNode(
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selections=self.many(
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TokenKind.BRACE_L, self.parse_selection, TokenKind.BRACE_R
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),
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loc=self.loc(start),
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)
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def parse_selection(self) -> SelectionNode:
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"""Selection: Field or FragmentSpread or InlineFragment"""
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return (
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self.parse_fragment if self.peek(TokenKind.SPREAD) else self.parse_field
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)()
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def parse_field(self) -> FieldNode:
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"""Field: Alias? Name Arguments? Directives? SelectionSet?"""
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start = self._lexer.token
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name_or_alias = self.parse_name()
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if self.expect_optional_token(TokenKind.COLON):
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alias: Optional[NameNode] = name_or_alias
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name = self.parse_name()
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else:
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alias = None
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name = name_or_alias
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return FieldNode(
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alias=alias,
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name=name,
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arguments=self.parse_arguments(False),
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directives=self.parse_directives(False),
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selection_set=(
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self.parse_selection_set() if self.peek(TokenKind.BRACE_L) else None
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),
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loc=self.loc(start),
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)
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def parse_arguments(self, is_const: bool) -> List[ArgumentNode]:
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"""Arguments[Const]: (Argument[?Const]+)"""
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item = self.parse_const_argument if is_const else self.parse_argument
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return self.optional_many(
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TokenKind.PAREN_L, cast(Callable[[], ArgumentNode], item), TokenKind.PAREN_R
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)
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def parse_argument(self, is_const: bool = False) -> ArgumentNode:
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"""Argument[Const]: Name : Value[?Const]"""
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start = self._lexer.token
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name = self.parse_name()
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self.expect_token(TokenKind.COLON)
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return ArgumentNode(
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name=name, value=self.parse_value_literal(is_const), loc=self.loc(start)
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)
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def parse_const_argument(self) -> ConstArgumentNode:
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"""Argument[Const]: Name : Value[Const]"""
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return cast(ConstArgumentNode, self.parse_argument(True))
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# Implement the parsing rules in the Fragments section.
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def parse_fragment(self) -> Union[FragmentSpreadNode, InlineFragmentNode]:
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"""Corresponds to both FragmentSpread and InlineFragment in the spec.
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FragmentSpread: ... FragmentName Directives?
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InlineFragment: ... TypeCondition? Directives? SelectionSet
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"""
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start = self._lexer.token
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self.expect_token(TokenKind.SPREAD)
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has_type_condition = self.expect_optional_keyword("on")
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if not has_type_condition and self.peek(TokenKind.NAME):
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return FragmentSpreadNode(
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name=self.parse_fragment_name(),
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directives=self.parse_directives(False),
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loc=self.loc(start),
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)
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return InlineFragmentNode(
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type_condition=self.parse_named_type() if has_type_condition else None,
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directives=self.parse_directives(False),
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selection_set=self.parse_selection_set(),
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loc=self.loc(start),
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)
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def parse_fragment_definition(self) -> FragmentDefinitionNode:
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"""FragmentDefinition"""
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start = self._lexer.token
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self.expect_keyword("fragment")
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# Legacy support for defining variables within fragments changes
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# the grammar of FragmentDefinition
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if self._allow_legacy_fragment_variables:
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return FragmentDefinitionNode(
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name=self.parse_fragment_name(),
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variable_definitions=self.parse_variable_definitions(),
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type_condition=self.parse_type_condition(),
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directives=self.parse_directives(False),
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selection_set=self.parse_selection_set(),
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loc=self.loc(start),
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)
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return FragmentDefinitionNode(
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name=self.parse_fragment_name(),
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type_condition=self.parse_type_condition(),
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directives=self.parse_directives(False),
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selection_set=self.parse_selection_set(),
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loc=self.loc(start),
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)
|
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def parse_fragment_name(self) -> NameNode:
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"""FragmentName: Name but not ``on``"""
|
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if self._lexer.token.value == "on":
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raise self.unexpected()
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return self.parse_name()
|
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|
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def parse_type_condition(self) -> NamedTypeNode:
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"""TypeCondition: NamedType"""
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self.expect_keyword("on")
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return self.parse_named_type()
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|
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# Implement the parsing rules in the Values section.
|
|
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_parse_value_literal_method_names: Dict[TokenKind, str] = {
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TokenKind.BRACKET_L: "list",
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TokenKind.BRACE_L: "object",
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TokenKind.INT: "int",
|
|
TokenKind.FLOAT: "float",
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TokenKind.STRING: "string_literal",
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TokenKind.BLOCK_STRING: "string_literal",
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TokenKind.NAME: "named_values",
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TokenKind.DOLLAR: "variable_value",
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}
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def parse_value_literal(self, is_const: bool) -> ValueNode:
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method_name = self._parse_value_literal_method_names.get(self._lexer.token.kind)
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if method_name: # pragma: no cover
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return getattr(self, f"parse_{method_name}")(is_const)
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raise self.unexpected() # pragma: no cover
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|
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def parse_string_literal(self, _is_const: bool = False) -> StringValueNode:
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token = self._lexer.token
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self.advance_lexer()
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return StringValueNode(
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value=token.value,
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block=token.kind == TokenKind.BLOCK_STRING,
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loc=self.loc(token),
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)
|
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def parse_list(self, is_const: bool) -> ListValueNode:
|
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"""ListValue[Const]"""
|
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start = self._lexer.token
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item = partial(self.parse_value_literal, is_const)
|
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# noinspection PyTypeChecker
|
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return ListValueNode(
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values=self.any(TokenKind.BRACKET_L, item, TokenKind.BRACKET_R),
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loc=self.loc(start),
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)
|
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|
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def parse_object_field(self, is_const: bool) -> ObjectFieldNode:
|
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start = self._lexer.token
|
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name = self.parse_name()
|
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self.expect_token(TokenKind.COLON)
|
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|
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return ObjectFieldNode(
|
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name=name, value=self.parse_value_literal(is_const), loc=self.loc(start)
|
|
)
|
|
|
|
def parse_object(self, is_const: bool) -> ObjectValueNode:
|
|
"""ObjectValue[Const]"""
|
|
start = self._lexer.token
|
|
item = partial(self.parse_object_field, is_const)
|
|
return ObjectValueNode(
|
|
fields=self.any(TokenKind.BRACE_L, item, TokenKind.BRACE_R),
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_int(self, _is_const: bool = False) -> IntValueNode:
|
|
token = self._lexer.token
|
|
self.advance_lexer()
|
|
return IntValueNode(value=token.value, loc=self.loc(token))
|
|
|
|
def parse_float(self, _is_const: bool = False) -> FloatValueNode:
|
|
token = self._lexer.token
|
|
self.advance_lexer()
|
|
return FloatValueNode(value=token.value, loc=self.loc(token))
|
|
|
|
def parse_named_values(self, _is_const: bool = False) -> ValueNode:
|
|
token = self._lexer.token
|
|
value = token.value
|
|
self.advance_lexer()
|
|
if value == "true":
|
|
return BooleanValueNode(value=True, loc=self.loc(token))
|
|
if value == "false":
|
|
return BooleanValueNode(value=False, loc=self.loc(token))
|
|
if value == "null":
|
|
return NullValueNode(loc=self.loc(token))
|
|
return EnumValueNode(value=value, loc=self.loc(token))
|
|
|
|
def parse_variable_value(self, is_const: bool) -> VariableNode:
|
|
if is_const:
|
|
variable_token = self.expect_token(TokenKind.DOLLAR)
|
|
token = self._lexer.token
|
|
if token.kind is TokenKind.NAME:
|
|
var_name = token.value
|
|
raise GraphQLSyntaxError(
|
|
self._lexer.source,
|
|
variable_token.start,
|
|
f"Unexpected variable '${var_name}' in constant value.",
|
|
)
|
|
raise self.unexpected(variable_token)
|
|
return self.parse_variable()
|
|
|
|
def parse_const_value_literal(self) -> ConstValueNode:
|
|
return cast(ConstValueNode, self.parse_value_literal(True))
|
|
|
|
# Implement the parsing rules in the Directives section.
|
|
|
|
def parse_directives(self, is_const: bool) -> List[DirectiveNode]:
|
|
"""Directives[Const]: Directive[?Const]+"""
|
|
directives: List[DirectiveNode] = []
|
|
append = directives.append
|
|
while self.peek(TokenKind.AT):
|
|
append(self.parse_directive(is_const))
|
|
return directives
|
|
|
|
def parse_const_directives(self) -> List[ConstDirectiveNode]:
|
|
return cast(List[ConstDirectiveNode], self.parse_directives(True))
|
|
|
|
def parse_directive(self, is_const: bool) -> DirectiveNode:
|
|
"""Directive[Const]: @ Name Arguments[?Const]?"""
|
|
start = self._lexer.token
|
|
self.expect_token(TokenKind.AT)
|
|
return DirectiveNode(
|
|
name=self.parse_name(),
|
|
arguments=self.parse_arguments(is_const),
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
# Implement the parsing rules in the Types section.
|
|
|
|
def parse_type_reference(self) -> TypeNode:
|
|
"""Type: NamedType or ListType or NonNullType"""
|
|
start = self._lexer.token
|
|
type_: TypeNode
|
|
if self.expect_optional_token(TokenKind.BRACKET_L):
|
|
inner_type = self.parse_type_reference()
|
|
self.expect_token(TokenKind.BRACKET_R)
|
|
type_ = ListTypeNode(type=inner_type, loc=self.loc(start))
|
|
else:
|
|
type_ = self.parse_named_type()
|
|
if self.expect_optional_token(TokenKind.BANG):
|
|
return NonNullTypeNode(type=type_, loc=self.loc(start))
|
|
return type_
|
|
|
|
def parse_named_type(self) -> NamedTypeNode:
|
|
"""NamedType: Name"""
|
|
start = self._lexer.token
|
|
return NamedTypeNode(name=self.parse_name(), loc=self.loc(start))
|
|
|
|
# Implement the parsing rules in the Type Definition section.
|
|
|
|
_parse_type_extension_method_names: Dict[str, str] = {
|
|
"schema": "schema_extension",
|
|
"scalar": "scalar_type_extension",
|
|
"type": "object_type_extension",
|
|
"interface": "interface_type_extension",
|
|
"union": "union_type_extension",
|
|
"enum": "enum_type_extension",
|
|
"input": "input_object_type_extension",
|
|
}
|
|
|
|
def parse_type_system_extension(self) -> TypeSystemExtensionNode:
|
|
"""TypeSystemExtension"""
|
|
keyword_token = self._lexer.lookahead()
|
|
if keyword_token.kind == TokenKind.NAME:
|
|
method_name = self._parse_type_extension_method_names.get(
|
|
cast(str, keyword_token.value)
|
|
)
|
|
if method_name: # pragma: no cover
|
|
return getattr(self, f"parse_{method_name}")()
|
|
raise self.unexpected(keyword_token)
|
|
|
|
def peek_description(self) -> bool:
|
|
return self.peek(TokenKind.STRING) or self.peek(TokenKind.BLOCK_STRING)
|
|
|
|
def parse_description(self) -> Optional[StringValueNode]:
|
|
"""Description: StringValue"""
|
|
if self.peek_description():
|
|
return self.parse_string_literal()
|
|
return None
|
|
|
|
def parse_schema_definition(self) -> SchemaDefinitionNode:
|
|
"""SchemaDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("schema")
|
|
directives = self.parse_const_directives()
|
|
operation_types = self.many(
|
|
TokenKind.BRACE_L, self.parse_operation_type_definition, TokenKind.BRACE_R
|
|
)
|
|
return SchemaDefinitionNode(
|
|
description=description,
|
|
directives=directives,
|
|
operation_types=operation_types,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_operation_type_definition(self) -> OperationTypeDefinitionNode:
|
|
"""OperationTypeDefinition: OperationType : NamedType"""
|
|
start = self._lexer.token
|
|
operation = self.parse_operation_type()
|
|
self.expect_token(TokenKind.COLON)
|
|
type_ = self.parse_named_type()
|
|
return OperationTypeDefinitionNode(
|
|
operation=operation, type=type_, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_scalar_type_definition(self) -> ScalarTypeDefinitionNode:
|
|
"""ScalarTypeDefinition: Description? scalar Name Directives[Const]?"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("scalar")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
return ScalarTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
directives=directives,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_object_type_definition(self) -> ObjectTypeDefinitionNode:
|
|
"""ObjectTypeDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("type")
|
|
name = self.parse_name()
|
|
interfaces = self.parse_implements_interfaces()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_fields_definition()
|
|
return ObjectTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
interfaces=interfaces,
|
|
directives=directives,
|
|
fields=fields,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_implements_interfaces(self) -> List[NamedTypeNode]:
|
|
"""ImplementsInterfaces"""
|
|
return (
|
|
self.delimited_many(TokenKind.AMP, self.parse_named_type)
|
|
if self.expect_optional_keyword("implements")
|
|
else []
|
|
)
|
|
|
|
def parse_fields_definition(self) -> List[FieldDefinitionNode]:
|
|
"""FieldsDefinition: {FieldDefinition+}"""
|
|
return self.optional_many(
|
|
TokenKind.BRACE_L, self.parse_field_definition, TokenKind.BRACE_R
|
|
)
|
|
|
|
def parse_field_definition(self) -> FieldDefinitionNode:
|
|
"""FieldDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
name = self.parse_name()
|
|
args = self.parse_argument_defs()
|
|
self.expect_token(TokenKind.COLON)
|
|
type_ = self.parse_type_reference()
|
|
directives = self.parse_const_directives()
|
|
return FieldDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
arguments=args,
|
|
type=type_,
|
|
directives=directives,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_argument_defs(self) -> List[InputValueDefinitionNode]:
|
|
"""ArgumentsDefinition: (InputValueDefinition+)"""
|
|
return self.optional_many(
|
|
TokenKind.PAREN_L, self.parse_input_value_def, TokenKind.PAREN_R
|
|
)
|
|
|
|
def parse_input_value_def(self) -> InputValueDefinitionNode:
|
|
"""InputValueDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
name = self.parse_name()
|
|
self.expect_token(TokenKind.COLON)
|
|
type_ = self.parse_type_reference()
|
|
default_value = (
|
|
self.parse_const_value_literal()
|
|
if self.expect_optional_token(TokenKind.EQUALS)
|
|
else None
|
|
)
|
|
directives = self.parse_const_directives()
|
|
return InputValueDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
type=type_,
|
|
default_value=default_value,
|
|
directives=directives,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_interface_type_definition(self) -> InterfaceTypeDefinitionNode:
|
|
"""InterfaceTypeDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("interface")
|
|
name = self.parse_name()
|
|
interfaces = self.parse_implements_interfaces()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_fields_definition()
|
|
return InterfaceTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
interfaces=interfaces,
|
|
directives=directives,
|
|
fields=fields,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_union_type_definition(self) -> UnionTypeDefinitionNode:
|
|
"""UnionTypeDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("union")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
types = self.parse_union_member_types()
|
|
return UnionTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
directives=directives,
|
|
types=types,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_union_member_types(self) -> List[NamedTypeNode]:
|
|
"""UnionMemberTypes"""
|
|
return (
|
|
self.delimited_many(TokenKind.PIPE, self.parse_named_type)
|
|
if self.expect_optional_token(TokenKind.EQUALS)
|
|
else []
|
|
)
|
|
|
|
def parse_enum_type_definition(self) -> EnumTypeDefinitionNode:
|
|
"""UnionTypeDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("enum")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
values = self.parse_enum_values_definition()
|
|
return EnumTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
directives=directives,
|
|
values=values,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_enum_values_definition(self) -> List[EnumValueDefinitionNode]:
|
|
"""EnumValuesDefinition: {EnumValueDefinition+}"""
|
|
return self.optional_many(
|
|
TokenKind.BRACE_L, self.parse_enum_value_definition, TokenKind.BRACE_R
|
|
)
|
|
|
|
def parse_enum_value_definition(self) -> EnumValueDefinitionNode:
|
|
"""EnumValueDefinition: Description? EnumValue Directives[Const]?"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
name = self.parse_enum_value_name()
|
|
directives = self.parse_const_directives()
|
|
return EnumValueDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
directives=directives,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_enum_value_name(self) -> NameNode:
|
|
"""EnumValue: Name but not ``true``, ``false`` or ``null``"""
|
|
if self._lexer.token.value in ("true", "false", "null"):
|
|
raise GraphQLSyntaxError(
|
|
self._lexer.source,
|
|
self._lexer.token.start,
|
|
f"{get_token_desc(self._lexer.token)} is reserved"
|
|
" and cannot be used for an enum value.",
|
|
)
|
|
return self.parse_name()
|
|
|
|
def parse_input_object_type_definition(self) -> InputObjectTypeDefinitionNode:
|
|
"""InputObjectTypeDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("input")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_input_fields_definition()
|
|
return InputObjectTypeDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
directives=directives,
|
|
fields=fields,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_input_fields_definition(self) -> List[InputValueDefinitionNode]:
|
|
"""InputFieldsDefinition: {InputValueDefinition+}"""
|
|
return self.optional_many(
|
|
TokenKind.BRACE_L, self.parse_input_value_def, TokenKind.BRACE_R
|
|
)
|
|
|
|
def parse_schema_extension(self) -> SchemaExtensionNode:
|
|
"""SchemaExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("schema")
|
|
directives = self.parse_const_directives()
|
|
operation_types = self.optional_many(
|
|
TokenKind.BRACE_L, self.parse_operation_type_definition, TokenKind.BRACE_R
|
|
)
|
|
if not directives and not operation_types:
|
|
raise self.unexpected()
|
|
return SchemaExtensionNode(
|
|
directives=directives, operation_types=operation_types, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_scalar_type_extension(self) -> ScalarTypeExtensionNode:
|
|
"""ScalarTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("scalar")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
if not directives:
|
|
raise self.unexpected()
|
|
return ScalarTypeExtensionNode(
|
|
name=name, directives=directives, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_object_type_extension(self) -> ObjectTypeExtensionNode:
|
|
"""ObjectTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("type")
|
|
name = self.parse_name()
|
|
interfaces = self.parse_implements_interfaces()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_fields_definition()
|
|
if not (interfaces or directives or fields):
|
|
raise self.unexpected()
|
|
return ObjectTypeExtensionNode(
|
|
name=name,
|
|
interfaces=interfaces,
|
|
directives=directives,
|
|
fields=fields,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_interface_type_extension(self) -> InterfaceTypeExtensionNode:
|
|
"""InterfaceTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("interface")
|
|
name = self.parse_name()
|
|
interfaces = self.parse_implements_interfaces()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_fields_definition()
|
|
if not (interfaces or directives or fields):
|
|
raise self.unexpected()
|
|
return InterfaceTypeExtensionNode(
|
|
name=name,
|
|
interfaces=interfaces,
|
|
directives=directives,
|
|
fields=fields,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_union_type_extension(self) -> UnionTypeExtensionNode:
|
|
"""UnionTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("union")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
types = self.parse_union_member_types()
|
|
if not (directives or types):
|
|
raise self.unexpected()
|
|
return UnionTypeExtensionNode(
|
|
name=name, directives=directives, types=types, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_enum_type_extension(self) -> EnumTypeExtensionNode:
|
|
"""EnumTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("enum")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
values = self.parse_enum_values_definition()
|
|
if not (directives or values):
|
|
raise self.unexpected()
|
|
return EnumTypeExtensionNode(
|
|
name=name, directives=directives, values=values, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_input_object_type_extension(self) -> InputObjectTypeExtensionNode:
|
|
"""InputObjectTypeExtension"""
|
|
start = self._lexer.token
|
|
self.expect_keyword("extend")
|
|
self.expect_keyword("input")
|
|
name = self.parse_name()
|
|
directives = self.parse_const_directives()
|
|
fields = self.parse_input_fields_definition()
|
|
if not (directives or fields):
|
|
raise self.unexpected()
|
|
return InputObjectTypeExtensionNode(
|
|
name=name, directives=directives, fields=fields, loc=self.loc(start)
|
|
)
|
|
|
|
def parse_directive_definition(self) -> DirectiveDefinitionNode:
|
|
"""DirectiveDefinition"""
|
|
start = self._lexer.token
|
|
description = self.parse_description()
|
|
self.expect_keyword("directive")
|
|
self.expect_token(TokenKind.AT)
|
|
name = self.parse_name()
|
|
args = self.parse_argument_defs()
|
|
repeatable = self.expect_optional_keyword("repeatable")
|
|
self.expect_keyword("on")
|
|
locations = self.parse_directive_locations()
|
|
return DirectiveDefinitionNode(
|
|
description=description,
|
|
name=name,
|
|
arguments=args,
|
|
repeatable=repeatable,
|
|
locations=locations,
|
|
loc=self.loc(start),
|
|
)
|
|
|
|
def parse_directive_locations(self) -> List[NameNode]:
|
|
"""DirectiveLocations"""
|
|
return self.delimited_many(TokenKind.PIPE, self.parse_directive_location)
|
|
|
|
def parse_directive_location(self) -> NameNode:
|
|
"""DirectiveLocation"""
|
|
start = self._lexer.token
|
|
name = self.parse_name()
|
|
if name.value in DirectiveLocation.__members__:
|
|
return name
|
|
raise self.unexpected(start)
|
|
|
|
# Core parsing utility functions
|
|
|
|
def loc(self, start_token: Token) -> Optional[Location]:
|
|
"""Return a location object.
|
|
|
|
Used to identify the place in the source that created a given parsed object.
|
|
"""
|
|
if not self._no_location:
|
|
end_token = self._lexer.last_token
|
|
source = self._lexer.source
|
|
return Location(start_token, end_token, source)
|
|
return None
|
|
|
|
def peek(self, kind: TokenKind) -> bool:
|
|
"""Determine if the next token is of a given kind"""
|
|
return self._lexer.token.kind == kind
|
|
|
|
def expect_token(self, kind: TokenKind) -> Token:
|
|
"""Expect the next token to be of the given kind.
|
|
|
|
If the next token is of the given kind, return that token after advancing the
|
|
lexer. Otherwise, do not change the parser state and throw an error.
|
|
"""
|
|
token = self._lexer.token
|
|
if token.kind == kind:
|
|
self.advance_lexer()
|
|
return token
|
|
|
|
raise GraphQLSyntaxError(
|
|
self._lexer.source,
|
|
token.start,
|
|
f"Expected {get_token_kind_desc(kind)}, found {get_token_desc(token)}.",
|
|
)
|
|
|
|
def expect_optional_token(self, kind: TokenKind) -> bool:
|
|
"""Expect the next token optionally to be of the given kind.
|
|
|
|
If the next token is of the given kind, return True after advancing the lexer.
|
|
Otherwise, do not change the parser state and return False.
|
|
"""
|
|
token = self._lexer.token
|
|
if token.kind == kind:
|
|
self.advance_lexer()
|
|
return True
|
|
|
|
return False
|
|
|
|
def expect_keyword(self, value: str) -> None:
|
|
"""Expect the next token to be a given keyword.
|
|
|
|
If the next token is a given keyword, advance the lexer.
|
|
Otherwise, do not change the parser state and throw an error.
|
|
"""
|
|
token = self._lexer.token
|
|
if token.kind == TokenKind.NAME and token.value == value:
|
|
self.advance_lexer()
|
|
else:
|
|
raise GraphQLSyntaxError(
|
|
self._lexer.source,
|
|
token.start,
|
|
f"Expected '{value}', found {get_token_desc(token)}.",
|
|
)
|
|
|
|
def expect_optional_keyword(self, value: str) -> bool:
|
|
"""Expect the next token optionally to be a given keyword.
|
|
|
|
If the next token is a given keyword, return True after advancing the lexer.
|
|
Otherwise, do not change the parser state and return False.
|
|
"""
|
|
token = self._lexer.token
|
|
if token.kind == TokenKind.NAME and token.value == value:
|
|
self.advance_lexer()
|
|
return True
|
|
|
|
return False
|
|
|
|
def unexpected(self, at_token: Optional[Token] = None) -> GraphQLError:
|
|
"""Create an error when an unexpected lexed token is encountered."""
|
|
token = at_token or self._lexer.token
|
|
return GraphQLSyntaxError(
|
|
self._lexer.source, token.start, f"Unexpected {get_token_desc(token)}."
|
|
)
|
|
|
|
def any(
|
|
self, open_kind: TokenKind, parse_fn: Callable[[], T], close_kind: TokenKind
|
|
) -> List[T]:
|
|
"""Fetch any matching nodes, possibly none.
|
|
|
|
Returns a possibly empty list of parse nodes, determined by the ``parse_fn``.
|
|
This list begins with a lex token of ``open_kind`` and ends with a lex token of
|
|
``close_kind``. Advances the parser to the next lex token after the closing
|
|
token.
|
|
"""
|
|
self.expect_token(open_kind)
|
|
nodes: List[T] = []
|
|
append = nodes.append
|
|
expect_optional_token = partial(self.expect_optional_token, close_kind)
|
|
while not expect_optional_token():
|
|
append(parse_fn())
|
|
return nodes
|
|
|
|
def optional_many(
|
|
self, open_kind: TokenKind, parse_fn: Callable[[], T], close_kind: TokenKind
|
|
) -> List[T]:
|
|
"""Fetch matching nodes, maybe none.
|
|
|
|
Returns a list of parse nodes, determined by the ``parse_fn``. It can be empty
|
|
only if the open token is missing, otherwise it will always return a non-empty
|
|
list that begins with a lex token of ``open_kind`` and ends with a lex token of
|
|
``close_kind``. Advances the parser to the next lex token after the closing
|
|
token.
|
|
"""
|
|
if self.expect_optional_token(open_kind):
|
|
nodes = [parse_fn()]
|
|
append = nodes.append
|
|
expect_optional_token = partial(self.expect_optional_token, close_kind)
|
|
while not expect_optional_token():
|
|
append(parse_fn())
|
|
return nodes
|
|
return []
|
|
|
|
def many(
|
|
self, open_kind: TokenKind, parse_fn: Callable[[], T], close_kind: TokenKind
|
|
) -> List[T]:
|
|
"""Fetch matching nodes, at least one.
|
|
|
|
Returns a non-empty list of parse nodes, determined by the ``parse_fn``. This
|
|
list begins with a lex token of ``open_kind`` and ends with a lex token of
|
|
``close_kind``. Advances the parser to the next lex token after the closing
|
|
token.
|
|
"""
|
|
self.expect_token(open_kind)
|
|
nodes = [parse_fn()]
|
|
append = nodes.append
|
|
expect_optional_token = partial(self.expect_optional_token, close_kind)
|
|
while not expect_optional_token():
|
|
append(parse_fn())
|
|
return nodes
|
|
|
|
def delimited_many(
|
|
self, delimiter_kind: TokenKind, parse_fn: Callable[[], T]
|
|
) -> List[T]:
|
|
"""Fetch many delimited nodes.
|
|
|
|
Returns a non-empty list of parse nodes, determined by the ``parse_fn``. This
|
|
list may begin with a lex token of ``delimiter_kind`` followed by items
|
|
separated by lex tokens of ``delimiter_kind``. Advances the parser to the next
|
|
lex token after the last item in the list.
|
|
"""
|
|
expect_optional_token = partial(self.expect_optional_token, delimiter_kind)
|
|
expect_optional_token()
|
|
nodes: List[T] = []
|
|
append = nodes.append
|
|
while True:
|
|
append(parse_fn())
|
|
if not expect_optional_token():
|
|
break
|
|
return nodes
|
|
|
|
def advance_lexer(self) -> None:
|
|
max_tokens = self._max_tokens
|
|
token = self._lexer.advance()
|
|
|
|
if max_tokens is not None and token.kind != TokenKind.EOF:
|
|
self._token_counter += 1
|
|
if self._token_counter > max_tokens:
|
|
raise GraphQLSyntaxError(
|
|
self._lexer.source,
|
|
token.start,
|
|
f"Document contains more than {max_tokens} tokens."
|
|
" Parsing aborted.",
|
|
)
|
|
|
|
|
|
def get_token_desc(token: Token) -> str:
|
|
"""Describe a token as a string for debugging."""
|
|
value = token.value
|
|
return get_token_kind_desc(token.kind) + (
|
|
f" '{value}'" if value is not None else ""
|
|
)
|
|
|
|
|
|
def get_token_kind_desc(kind: TokenKind) -> str:
|
|
"""Describe a token kind as a string for debugging."""
|
|
return f"'{kind.value}'" if is_punctuator_token_kind(kind) else kind.value
|