/// <summary>
/// Parses a type reference.
/// <see cref="ITypeNode" />:
/// - NamedType
/// - ListType
/// - NonNullType
/// </summary>
/// <param name="context">The parser context.</param>
private ITypeNode ParseTypeReference(ParserContext context)
{
SyntaxToken start = context.Current;
ITypeNode type;
Location location;
if (context.Skip(TokenKind.LeftBracket))
{
type = ParseTypeReference(context);
context.ExpectRightBracket();
location = context.CreateLocation(start);
type = new ListTypeNode(location, type);
}
else
{
type = ParseNamedType(context);
}
if (context.Skip(TokenKind.Bang))
{
if (type is INullableType nt)
{
return(new NonNullTypeNode
(
context.CreateLocation(start),
nt
));
}
context.Unexpected(context.Current.Previous);
}
return(type);
}
private List <NameNode> ParseDirectiveLocations(ParserContext context)
{
List <NameNode> list = new List <NameNode>();
// skip optional leading pipe.
context.Skip(TokenKind.Pipe);
do
{
list.Add(ParseDirectiveLocation(context));
}while (context.Skip(TokenKind.Pipe));
return(list);
}
public static void SkipWhile(this ParserContext context, TokenKind kind)
{
while (context.Skip(kind))
{
;
}
}
/// <summary>
/// Parses input value definitions.
/// <see cref="InputValueDefinitionNode" />:
/// Description? Name : Type DefaultValue? Directives[isConstant=true]?
/// </summary>
/// <param name="context">The parser context.</param>
private InputValueDefinitionNode ParseInputValueDefinition(
ParserContext context)
{
SyntaxToken start = context.Current;
StringValueNode description = ParseDescription(context);
NameNode name = ParseName(context);
context.ExpectColon();
ITypeNode type = ParseTypeReference(context);
IValueNode defaultValue = null;
if (context.Skip(TokenKind.Equal))
{
defaultValue = ParseConstantValue(context);
}
List <DirectiveNode> directives =
ParseDirectives(context, true);
Location location = context.CreateLocation(start);
return(new InputValueDefinitionNode
(
location,
name,
description,
type,
defaultValue,
directives
));
}
/// <summary>
/// Parses the union member types.
/// <see cref="List{NamedTypeNode}" />:
/// = `|`? NamedType
/// </summary>
/// <param name="context">The parser context.</param>
private List <NamedTypeNode> ParseUnionMemberTypes(
ParserContext context)
{
List <NamedTypeNode> list = new List <NamedTypeNode>();
if (context.Skip(TokenKind.Equal))
{
// skip optional leading pipe
context.Skip(TokenKind.Pipe);
do
{
list.Add(ParseNamedType(context));
}while (context.Skip(TokenKind.Pipe));
}
return(list);
}
/// <summary>
/// Parses implementing interfaces.
/// <see cref="List{NamedTypeNode}" />:
/// implements &? NamedType
/// </summary>
/// <param name="context">The parser context.</param>
private List <NamedTypeNode> ParseImplementsInterfaces(
ParserContext context)
{
List <NamedTypeNode> list = new List <NamedTypeNode>();
if (context.SkipKeyword(Keywords.Implements))
{
// skip optional leading amperdand.
context.Skip(TokenKind.Ampersand);
do
{
list.Add(ParseNamedType(context));
}while (context.Skip(TokenKind.Ampersand));
}
return(list);
}
/// <summary>
/// Parses a variable definition.
/// <see cref="VariableDefinitionNode" />:
/// $variable : Type = DefaultValue?
/// </summary>
/// <param name="context">The parser context.</param>
private VariableDefinitionNode ParseVariableDefinition(ParserContext context)
{
SyntaxToken start = context.Current;
VariableNode variable = ParseVariable(context);
context.ExpectColon();
ITypeNode type = ParseTypeReference(context);
IValueNode defaultValue = context.Skip(TokenKind.Equal)
? ParseValueLiteral(context, true)
: null;
Location location = context.CreateLocation(start);
return(new VariableDefinitionNode
(
location,
variable,
type,
defaultValue
));
}