[RFC] Merge Grammar chapter into Language chapter

I think it would be more clear if we merged the grammar chapter into the language chapter of the spec, introducing grammar as we explain parts of the language. This ensures that we're describing how the language works as we introduce it while at the same time being careful not to rely on concepts before their introduced. Some things were being described twice in subtley different ways.

The main drawback is that there is more normative text and examples between the grammar rules, so this also adds another appendix section containing only grammar rules as an informative aid.

Author: leebyron

Appendix B -- Grammar Summary.md

@@ -0,0 +1,173 @@
+# B. Appendix: Grammar Summary
+
+SourceCharacter :: "Any Unicode code point"
+
+
+## Ignored Tokens
+
+Ignored ::
+  - WhiteSpace
+  - LineTerminator
+  - Comment
+  - Comma
+
+WhiteSpace ::
+  - "Horizontal Tab (U+0009)"
+  - "Vertical Tab (U+000B)"
+  - "Form Feed (U+000C)"
+  - "Space (U+0020)"
+  - "No-break Space (U+00A0)"
+
+LineTerminator ::
+  - "New Line (U+000A)"
+  - "Carriage Return (U+000D)"
+  - "Line Separator (U+2028)"
+  - "Paragraph Separator (U+2029)"
+
+Comment ::
+  - `#` CommentChar*
+
+CommentChar :: SourceCharacter but not LineTerminator
+
+Comma :: ,
+
+
+## Lexical Tokens
+
+Token ::
+  - Punctuator
+  - Name
+  - IntValue
+  - FloatValue
+  - StringValue
+
+Punctuator :: one of ! $ ( ) ... : = @ [ ] { | }
+
+Name :: /[_A-Za-z][_0-9A-Za-z]*/
+
+IntValue :: IntegerPart
+
+IntegerPart ::
+  - NegativeSign? 0
+  - NegativeSign? NonZeroDigit Digit*
+
+NegativeSign :: -
+
+Digit :: one of 0 1 2 3 4 5 6 7 8 9
+
+NonZeroDigit :: Digit but not `0`
+
+FloatValue ::
+  - IntegerPart FractionalPart
+  - IntegerPart ExponentPart
+  - IntegerPart FractionalPart ExponentPart
+
+FractionalPart :: . Digit+
+
+ExponentPart :: ExponentIndicator Sign? Digit+
+
+ExponentIndicator :: one of `e` `E`
+
+Sign :: one of + -
+
+StringValue ::
+  - `""`
+  - `"` StringCharacter+ `"`
+
+StringCharacter ::
+  - SourceCharacter but not `"` or \ or LineTerminator
+  - \ EscapedUnicode
+  - \ EscapedCharacter
+
+EscapedUnicode :: u /[0-9A-Fa-f]{4}/
+
+EscapedCharacter :: one of `"` \ `/` b f n r t
+
+
+## Query Document
+
+Document : Definition+
+
+Definition :
+  - OperationDefinition
+  - FragmentDefinition
+
+OperationDefinition :
+  - SelectionSet
+  - OperationType Name VariableDefinitions? Directives? SelectionSet
+
+OperationType : one of query mutation
+
+SelectionSet : { Selection+ }
+
+Selection :
+  - Field
+  - FragmentSpread
+  - InlineFragment
+
+Field : Alias? Name Arguments? Directives? SelectionSet?
+
+Alias : Name :
+
+Arguments : ( Argument+ )
+
+Argument : Name : Value
+
+FragmentSpread : ... FragmentName Directives?
+
+InlineFragment : ... on TypeCondition Directives? SelectionSet
+
+FragmentDefinition : fragment FragmentName on TypeCondition Directives? SelectionSet
+
+FragmentName : Name but not `on`
+
+TypeCondition : NamedType
+
+Value[Const] :
+  - [~Const] Variable
+  - IntValue
+  - FloatValue
+  - StringValue
+  - BooleanValue
+  - EnumValue
+  - ArrayValue[?Const]
+  - ObjectValue[?Const]
+
+BooleanValue : one of `true` `false`
+
+EnumValue : Name but not `true`, `false` or `null`
+
+ArrayValue[Const] :
+  - [ ]
+  - [ Value[?Const]+ ]
+
+ObjectValue[Const] :
+  - { }
+  - { ObjectField[?Const]+ }
+
+ObjectField[Const] : Name : Value[?Const]
+
+VariableDefinitions : ( VariableDefinition+ )
+
+VariableDefinition : Variable : Type DefaultValue?
+
+Variable : $ Name
+
+DefaultValue : = Value[Const]
+
+Type :
+  - NamedType
+  - ListType
+  - NonNullType
+
+NamedType : Name
+
+ListType : [ Type ]
+
+NonNullType :
+  - NamedType !
+  - ListType !
+
+Directives : Directive+
+
+Directive : @ Name Arguments?

GraphQL.md

@@ -54,6 +54,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 # [Response](Section 7 -- Response.md)
 
-# [Grammar](Section 8 -- Grammar.md)
-
 # [Appendix: Notation Conventions](Appendix A -- Notation Conventions.md)
+
+# [Appendix: Grammar Summary](Appendix B -- Grammar Summary.md)