Updating schema parser to more closely match current state of RFC

graphql/graphql-spec#90

Author: leebyron

src/language/ast.js

@@ -77,9 +77,7 @@ export type Document = {
 
 export type Definition = OperationDefinition
                        | FragmentDefinition
-                       | TypeDefinition
-                       | TypeExtensionDefinition
-                       | DirectiveDefinition
+                       | TypeSystemDefinition
 
 export type OperationDefinition = {
   kind: 'OperationDefinition';
@@ -256,15 +254,25 @@ export type NonNullType = {
   type: NamedType | ListType;
 }
 
-// Type Definition
+// Type System Definition
 
-export type TypeDefinition = ObjectTypeDefinition
+export type TypeSystemDefinition = TypeDefinition
+                                 | TypeExtensionDefinition
+                                 | DirectiveDefinition
+
+export type TypeDefinition = ScalarTypeDefinition
+                           | ObjectTypeDefinition
                            | InterfaceTypeDefinition
                            | UnionTypeDefinition
-                           | ScalarTypeDefinition
                            | EnumTypeDefinition
                            | InputObjectTypeDefinition
 
+export type ScalarTypeDefinition = {
+  kind: 'ScalarTypeDefinition';
+  loc?: ?Location;
+  name: Name;
+}
+
 export type ObjectTypeDefinition = {
   kind: 'ObjectTypeDefinition';
   loc?: ?Location;
@@ -303,12 +311,6 @@ export type UnionTypeDefinition = {
   types: Array<NamedType>;
 }
 
-export type ScalarTypeDefinition = {
-  kind: 'ScalarTypeDefinition';
-  loc?: ?Location;
-  name: Name;
-}
-
 export type EnumTypeDefinition = {
   kind: 'EnumTypeDefinition';
   loc?: ?Location;

src/language/kinds.js

@@ -48,14 +48,16 @@ export const NAMED_TYPE = 'NamedType';
 export const LIST_TYPE = 'ListType';
 export const NON_NULL_TYPE = 'NonNullType';
 
+// Type System Definitions
+
 // Type Definitions
 
+export const SCALAR_TYPE_DEFINITION = 'ScalarTypeDefinition';
 export const OBJECT_TYPE_DEFINITION = 'ObjectTypeDefinition';
 export const FIELD_DEFINITION = 'FieldDefinition';
 export const INPUT_VALUE_DEFINITION = 'InputValueDefinition';
 export const INTERFACE_TYPE_DEFINITION = 'InterfaceTypeDefinition';
 export const UNION_TYPE_DEFINITION = 'UnionTypeDefinition';
-export const SCALAR_TYPE_DEFINITION = 'ScalarTypeDefinition';
 export const ENUM_TYPE_DEFINITION = 'EnumTypeDefinition';
 export const ENUM_VALUE_DEFINITION = 'EnumValueDefinition';
 export const INPUT_OBJECT_TYPE_DEFINITION = 'InputObjectTypeDefinition';

src/language/parser.js

@@ -39,13 +39,14 @@ import type {
   Type,
   NamedType,
 
-  TypeDefinition,
+  TypeSystemDefinition,
+
+  ScalarTypeDefinition,
   ObjectTypeDefinition,
   FieldDefinition,
   InputValueDefinition,
   InterfaceTypeDefinition,
   UnionTypeDefinition,
-  ScalarTypeDefinition,
   EnumTypeDefinition,
   EnumValueDefinition,
   InputObjectTypeDefinition,
@@ -85,12 +86,12 @@ import {
   LIST_TYPE,
   NON_NULL_TYPE,
 
+  SCALAR_TYPE_DEFINITION,
   OBJECT_TYPE_DEFINITION,
   FIELD_DEFINITION,
   INPUT_VALUE_DEFINITION,
   INTERFACE_TYPE_DEFINITION,
   UNION_TYPE_DEFINITION,
-  SCALAR_TYPE_DEFINITION,
   ENUM_TYPE_DEFINITION,
   ENUM_VALUE_DEFINITION,
   INPUT_OBJECT_TYPE_DEFINITION,
@@ -185,8 +186,7 @@ function parseDocument(parser: Parser): Document {
  * Definition :
  *   - OperationDefinition
  *   - FragmentDefinition
- *   - TypeDefinition
- *   - TypeExtensionDefinition
+ *   - TypeSystemDefinition
  */
 function parseDefinition(parser: Parser): Definition {
   if (peek(parser, TokenKind.BRACE_L)) {
@@ -202,14 +202,15 @@ function parseDefinition(parser: Parser): Definition {
 
       case 'fragment': return parseFragmentDefinition(parser);
 
+      // Note: the Type System IDL is an experimental non-spec addition.
+      case 'scalar':
       case 'type':
       case 'interface':
       case 'union':
-      case 'scalar':
       case 'enum':
-      case 'input': return parseTypeDefinition(parser);
-      case 'extend': return parseTypeExtensionDefinition(parser);
-      case 'directive': return parseDirectiveDefinition(parser);
+      case 'input':
+      case 'extend':
+      case 'directive': return parseTypeSystemDefinition(parser);
     }
   }
 
@@ -649,34 +650,48 @@ export function parseNamedType(parser: Parser): NamedType {
 // Implements the parsing rules in the Type Definition section.
 
 /**
+ * TypeSystemDefinition :
+ *   - TypeDefinition
+ *   - TypeExtensionDefinition
+ *   - DirectiveDefinition
+ *
  * TypeDefinition :
+ *   - ScalarTypeDefinition
  *   - ObjectTypeDefinition
  *   - InterfaceTypeDefinition
  *   - UnionTypeDefinition
- *   - ScalarTypeDefinition
  *   - EnumTypeDefinition
  *   - InputObjectTypeDefinition
  */
-function parseTypeDefinition(parser: Parser): TypeDefinition {
-  if (!peek(parser, TokenKind.NAME)) {
-    throw unexpected(parser);
-  }
-  switch (parser.token.value) {
-    case 'type':
-      return parseObjectTypeDefinition(parser);
-    case 'interface':
-      return parseInterfaceTypeDefinition(parser);
-    case 'union':
-      return parseUnionTypeDefinition(parser);
-    case 'scalar':
-      return parseScalarTypeDefinition(parser);
-    case 'enum':
-      return parseEnumTypeDefinition(parser);
-    case 'input':
-      return parseInputObjectTypeDefinition(parser);
-    default:
-      throw unexpected(parser);
+function parseTypeSystemDefinition(parser: Parser): TypeSystemDefinition {
+  if (peek(parser, TokenKind.NAME)) {
+    switch (parser.token.value) {
+      case 'scalar': return parseScalarTypeDefinition(parser);
+      case 'type': return parseObjectTypeDefinition(parser);
+      case 'interface': return parseInterfaceTypeDefinition(parser);
+      case 'union': return parseUnionTypeDefinition(parser);
+      case 'enum': return parseEnumTypeDefinition(parser);
+      case 'input': return parseInputObjectTypeDefinition(parser);
+      case 'extend': return parseTypeExtensionDefinition(parser);
+      case 'directive': return parseDirectiveDefinition(parser);
+    }
   }
+
+  throw unexpected(parser);
+}
+
+/**
+ * ScalarTypeDefinition : scalar Name
+ */
+function parseScalarTypeDefinition(parser: Parser): ScalarTypeDefinition {
+  const start = parser.token.start;
+  expectKeyword(parser, 'scalar');
+  const name = parseName(parser);
+  return {
+    kind: SCALAR_TYPE_DEFINITION,
+    name,
+    loc: loc(parser, start),
+  };
 }
 
 /**
@@ -816,20 +831,6 @@ function parseUnionMembers(parser: Parser): Array<NamedType> {
   return members;
 }
 
-/**
- * ScalarTypeDefinition : scalar Name
- */
-function parseScalarTypeDefinition(parser: Parser): ScalarTypeDefinition {
-  const start = parser.token.start;
-  expectKeyword(parser, 'scalar');
-  const name = parseName(parser);
-  return {
-    kind: SCALAR_TYPE_DEFINITION,
-    name,
-    loc: loc(parser, start),
-  };
-}
-
 /**
  * EnumTypeDefinition : enum Name { EnumValueDefinition+ }
  */

src/language/printer.js

@@ -92,7 +92,10 @@ const printDocASTReducer = {
   ListType: ({ type }) => '[' + type + ']',
   NonNullType: ({ type }) => type + '!',
 
-  // Type Definitions
+  // Type System Definitions
+
+  ScalarTypeDefinition: ({ name }) =>
+    `scalar ${name}`,
 
   ObjectTypeDefinition: ({ name, interfaces, fields }) =>
     'type ' + name + ' ' +
@@ -111,9 +114,6 @@ const printDocASTReducer = {
   UnionTypeDefinition: ({ name, types }) =>
     `union ${name} = ${join(types, ' | ')}`,
 
-  ScalarTypeDefinition: ({ name }) =>
-    `scalar ${name}`,
-
   EnumTypeDefinition: ({ name, values }) =>
     `enum ${name} ${block(values)}`,