* = list of 0 or more
+ = list of 1 or more
? = optional, 0 or 1

Basic Definitions

  SourceCharacter :: /[\u0009\u000A\u000D\u0020-\uFFFF]/
  UnicodeBOM :: Byte Order Mark (U+FEFF) (unicode chars may appear in StringValue and Comment portions)
  WhiteSpace :: Horizontal Tab (U+0009) or Space (U+0020)
  LineTerminator :: New Line (U+000A) or Carriage Return (U+000D)New Line (U+000A) or Carriage Return (U+000D)New Line (U+000A)
  Comment :: #CommentChar*
  CommentChar :: SourceCharacter but not LineTerminator
  Comma :: ,
  Token :: Punctuator or Name or IntValue or FloatValue or StringValue (lexical token)
  Ignored :: UnicodeBOM or WhiteSpace or LineTerminator or Comment or Comma (ignored tokens, may appear in any quantity before or after any lexical token)
  Punctuator :: ! $ ( ) ... : = @ [ ] { | }
  Name :: /[_A-Za-z][_0-9A-Za-z]*/ (case sensitive, limited to ASCII)

Documents

  Document :: Definition+
  Definition :: OperationDefinition or FragmentDefinition (If a document contains only one operation, that operation may be unnamed or represented in the shorthand form, which omits both the query keyword and operation name. Otherwise, if a GraphQL query document contains multiple operations, each operation must be named. When submitting a query document with multiple operations to a GraphQL service, the name of the desired operation to be executed must also be provided.)

Operations

  There are two kinds of operations, queries (read only) and mutations (write followed by read)

  OperationDefinition :: OperationType Name? VariableDefinitions? Directives? SelectionSet
                         OR just SelectionSet for shorthand, but only if document contains just one definition
  OperationType :: `query` or `mutation`.

Selection Sets

  SelectionSet :: { Selection+ }
  Selection :: Field or FragementSpread or InlineFragment
  Field :: Alias? Name Arguments? Directives? SelectionSet?
  Alias :: Name :

Arguments

  Arguments are unordered.

  Arguments :: ( Argument+ )
  Argument :: Name : Value

Fragments

  FragmentSpread :: `...` FragmentName Directives?
  FragmentDefinition :: `fragment` FragmentName TypeCondition Directives? SelectionSet
  FragmentName :: Name but not `on`
  TypeCondition :: `on` NamedType
  InlineFragment :: `...` TypeCondition? Directives? SelectionSet

Input Values

  Value :: Variable or IntValue or FloatValue or StringValue or BooleanValue or EnumValue or ListValue or ObjectValue
  TODO something about constant values

  IntValue:: IntegerPart
  IntegerPart :: NegativeSign? `0`
                 OR NegativeSign? NonZeroDigit Digit*
  NegativeSign :: -
  Digit :: one of 0-9
  NonZeroDigit:: Digit but not 0

  FloatValue :: IntegerPart FractionalPart
                OR IntegerPart ExponentPart
                OR IntegerPart FractionalPart ExponentPart
  FractionalPart :: `.` Digit+
  ExponentPart :: ExponentIndicator S