Add semantic optional type

Author: twof

src/language/ast.ts

@@ -162,6 +162,7 @@ export type ASTNode =
   | ListTypeNode
   | NonNullTypeNode
   | SemanticNonNullTypeNode
+  | SemanticOptionalTypeNode
   | SchemaDefinitionNode
   | OperationTypeDefinitionNode
   | ScalarTypeDefinitionNode
@@ -237,6 +238,7 @@ export const QueryDocumentKeys: {
   ListType: ['type'],
   NonNullType: ['type'],
   SemanticNonNullType: ['type'],
+  SemanticOptionalType: ['type'],
 
   SchemaDefinition: ['description', 'directives', 'operationTypes'],
   OperationTypeDefinition: ['type'],
@@ -526,7 +528,8 @@ export type TypeNode =
   | NamedTypeNode
   | ListTypeNode
   | NonNullTypeNode
-  | SemanticNonNullTypeNode;
+  | SemanticNonNullTypeNode
+  | SemanticOptionalTypeNode;
 
 export interface NamedTypeNode {
   readonly kind: Kind.NAMED_TYPE;
@@ -552,6 +555,12 @@ export interface SemanticNonNullTypeNode {
   readonly type: NamedTypeNode | ListTypeNode;
 }
 
+export interface SemanticOptionalTypeNode {
+  readonly kind: Kind.SEMANTIC_OPTIONAL_TYPE;
+  readonly loc?: Location;
+  readonly type: NamedTypeNode | ListTypeNode;
+}
+
 /** Type System Definition */
 
 export type TypeSystemDefinitionNode =

src/language/kinds.ts

@@ -38,6 +38,7 @@ enum Kind {
   LIST_TYPE = 'ListType',
   NON_NULL_TYPE = 'NonNullType',
   SEMANTIC_NON_NULL_TYPE = 'SemanticNonNullType',
+  SEMANTIC_OPTIONAL_TYPE = 'SemanticOptionalType',
 
   /** Type System Definitions */
   SCHEMA_DEFINITION = 'SchemaDefinition',

src/language/parser.ts

@@ -51,6 +51,7 @@ import type {
   SelectionNode,
   SelectionSetNode,
   SemanticNonNullTypeNode,
+  SemanticOptionalTypeNode,
   StringValueNode,
   Token,
   TypeNode,
@@ -774,7 +775,10 @@ export class Parser {
           type,
         });
       } else if (this.expectOptionalToken(TokenKind.QUESTION_MARK)) {
-        return type;
+        return this.node<SemanticOptionalTypeNode>(start, {
+          kind: Kind.SEMANTIC_OPTIONAL_TYPE,
+          type,
+        });
       } else {
         return this.node<SemanticNonNullTypeNode>(start, {
           kind: Kind.SEMANTIC_NON_NULL_TYPE,

src/language/printer.ts

@@ -6,11 +6,18 @@ import { printString } from './printString';
 import type { ASTReducer } from './visitor';
 import { visit } from './visitor';
 
+/**
+ * Configuration options to control parser behavior
+ */
+export interface PrintOptions {
+  useSemanticNullability?: boolean;
+}
+
 /**
  * Converts an AST into a string, using one set of reasonable
  * formatting rules.
  */
-export function print(ast: ASTNode): string {
+export function print(ast: ASTNode, options: PrintOptions = {}): string {
   return visit(ast, printDocASTReducer);
 }
 
@@ -128,10 +135,13 @@ const printDocASTReducer: ASTReducer<string> = {
 
   // Type
 
-  NamedType: { leave: ({ name }) => name },
+  NamedType: { leave: ({ name }) => 
+    name 
+},
   ListType: { leave: ({ type }) => '[' + type + ']' },
   NonNullType: { leave: ({ type }) => type + '!' },
-  SemanticNonNullType: { leave: ({ type }) => type + '*' },
+  SemanticNonNullType: { leave: ({ type }) => type },
+  SemanticOptionalType: { leave: ({ type }) => type + '?' },
 
   // Type System Definitions