Use :: syntax for enum values

Author: benjie

spec/Appendix B -- Grammar Summary.md

@@ -45,12 +45,15 @@ Token ::
 
 Punctuator ::
 
+- ColonPunctuator
 - DotPunctuator
 - OtherPunctuator
 
+ColonPunctuator :: `:` [lookahead != {`:`}]
+
 DotPunctuator :: `.` [lookahead != {`.`, Digit}]
 
-OtherPunctuator :: one of ! $ & ( ) ... : = @ [ ] { | }
+OtherPunctuator :: one of ! $ & ( ) ... :: = @ [ ] { | }
 
 Name ::
 
@@ -423,17 +426,20 @@ TypeSystemDirectiveLocation : one of
 SchemaCoordinate :
 
 - TypeCoordinate
-- MemberCoordinate
+- FieldCoordinate
 - ArgumentCoordinate
+- ValueCoordinate
 - DirectiveCoordinate
 - DirectiveArgumentCoordinate
 
 TypeCoordinate : Name
 
-MemberCoordinate : Name . Name
+FieldCoordinate : Name . Name
 
 ArgumentCoordinate : Name . Name ( Name : )
 
+ValueCoordinate : Name :: Name
+
 DirectiveCoordinate : @ Name
 
 DirectiveArgumentCoordinate : @ Name ( Name : )

spec/Section 2 -- Language.md

@@ -178,17 +178,23 @@ and is {Ignored}.
 
 Punctuator ::
 
+- ColonPunctuator
 - DotPunctuator
 - OtherPunctuator
 
+ColonPunctuator :: `:` [lookahead != {`:`}]
+
 DotPunctuator :: `.` [lookahead != {`.`, Digit}]
 
-OtherPunctuator :: one of ! $ & ( ) ... : = @ [ ] { | }
+OtherPunctuator :: one of ! $ & ( ) ... :: = @ [ ] { | }
 
 GraphQL documents include punctuation in order to describe structure. GraphQL is
 a data description language and not a programming language, therefore GraphQL
 lacks the punctuation often used to describe mathematical expressions.
 
+The {`:`} punctuator must not be followed by a {`:`}. This ensures that the
+source {"::"} can only be interpreted as a single {`::`} and not two {`:`}.
+
 The {`.`} punctuator must not be followed by a {`.`} or {Digit}. This ensures
 that the source {"..."} can only be interpreted as a single {`...`} and not
 three {`.`}. It also avoids any potential ambiguity with {FloatValue}. As an

spec/Section 3 -- Type System.md

@@ -2174,17 +2174,20 @@ scalar UUID @specifiedBy(url: "https://tools.ietf.org/html/rfc4122")
 SchemaCoordinate :
 
 - TypeCoordinate
-- MemberCoordinate
+- FieldCoordinate
 - ArgumentCoordinate
+- ValueCoordinate
 - DirectiveCoordinate
 - DirectiveArgumentCoordinate
 
 TypeCoordinate : Name
 
-MemberCoordinate : Name . Name
+FieldCoordinate : Name . Name
 
 ArgumentCoordinate : Name . Name ( Name : )
 
+ValueCoordinate : Name :: Name
+
 DirectiveCoordinate : @ Name
 
 DirectiveArgumentCoordinate : @ Name ( Name : )
@@ -2195,6 +2198,16 @@ _schema element_ within a GraphQL Schema.
 :: A _schema element_ can be a named type, a field, an input field, an enum
 value, a field argument, a directive, or a directive argument.
 
+:: The _containing element_ of a _schema element_ is the schema element with one
+fewer {Name} token that syntactically contains it. For example:
+
+- The containing element of an {ArgumentCoordinate} or
+  {DirectiveArgumentCoordinate} is the corresponding {FieldCoordinate} or
+  {DirectiveCoordinate} respectively.
+- The containing element of a {FieldCoordinate} or {ValueCoordinate} is its
+  containing {TypeCoordinate}.
+- {TypeCoordinate} and {DirectiveCoordinate} have no containing element.
+
 A _schema coordinate_ is always unique. Each _schema element_ can be referenced
 by exactly one possible schema coordinate.
 
@@ -2220,31 +2233,27 @@ production.
 To refer to a _schema element_, a _schema coordinate_ must be interpreted in the
 context of a GraphQL {schema}.
 
-If the _schema element_ cannot be found, the resolve function will not yield a
-value (without raising an error). However, an error will be raised if any
-non-leaf nodes within a _schema coordinate_ cannot be found in the {schema}.
+If the _schema element_ cannot be found, and either it has no _containing
+element_ or its _containing element_ exists and is of the expected type, the
+resolve function returns {null}. Otherwise, an error is raised.
 
 TypeCoordinate : Name
 
 1. Let {typeName} be the value of {Name}.
 2. Return the type in the {schema} named {typeName}, or {null} if no such type
    exists.
 
-MemberCoordinate : Name . Name
+FieldCoordinate : Name . Name
 
 1. Let {typeName} be the value of the first {Name}.
 2. Let {type} be the type in the {schema} named {typeName}.
-3. Assert: {type} must exist, and must be an Enum, Input Object, Object or
-   Interface type.
-4. If {type} is an Enum type:
-   1. Let {enumValueName} be the value of the second {Name}.
-   2. Return the enum value of {type} named {enumValueName}, or {null} if no
-      such value exists.
-5. Otherwise, if {type} is an Input Object type:
+3. Assert: {type} must exist, and must be an Input Object, Object or Interface
+   type.
+4. If {type} is an Input Object type:
    1. Let {inputFieldName} be the value of the second {Name}.
    2. Return the input field of {type} named {inputFieldName}, or {null} if no
       such input field exists.
-6. Otherwise:
+5. Otherwise:
    1. Let {fieldName} be the value of the second {Name}.
    2. Return the field of {type} named {fieldName}, or {null} if no such field
       exists.
@@ -2261,6 +2270,15 @@ ArgumentCoordinate : Name . Name ( Name : )
 8. Return the argument of {field} named {fieldArgumentName}, or {null} if no
    such argument exists.
 
+ValueCoordinate : Name :: Name
+
+1. Let {typeName} be the value of the first {Name}.
+2. Let {type} be the type in the {schema} named {typeName}.
+3. Assert: {type} must exist, and must be an Enum type.
+4. Let {enumValueName} be the value of the second {Name}.
+5. Return the enum value of {type} named {enumValueName}, or {null} if no such
+   value exists.
+
 DirectiveCoordinate : @ Name
 
 1. Let {directiveName} be the value of {Name}.
@@ -2283,8 +2301,8 @@ DirectiveArgumentCoordinate : @ Name ( Name : )
 | Named Type         | `Business`                        | `Business` type                                                       |
 | Field              | `Business.name`                   | `name` field on the `Business` type                                   |
 | Input Field        | `SearchCriteria.filter`           | `filter` input field on the `SearchCriteria` input object type        |
-| Enum Value         | `SearchFilter.OPEN_NOW`           | `OPEN_NOW` value of the `SearchFilter` enum                           |
 | Field Argument     | `Query.searchBusiness(criteria:)` | `criteria` argument on the `searchBusiness` field on the `Query` type |
+| Enum Value         | `SearchFilter::OPEN_NOW`          | `OPEN_NOW` value of the `SearchFilter` enum                           |
 | Directive          | `@private`                        | `@private` directive                                                  |
 | Directive Argument | `@private(scope:)`                | `scope` argument on the `@private` directive                          |