Merge pull request #1187 from glacambre/singleton_types

Metadata Types: Use a single type instance where it makes sense

compiler/types/AnyType.ts

@@ -1,12 +1,13 @@
 import { Type } from "./Type"
 
 export class AnyType implements Type {
+    static instance = new AnyType()
     kind = "any"
 
     constructor() {}
 
     toConstructor() {
-        return "new AnyType()"
+        return "AnyType.instance"
     }
 
     toString() {

compiler/types/BooleanType.ts

@@ -1,12 +1,13 @@
 import { Type } from "./Type"
 
 export class BooleanType implements Type {
+    static instance = new BooleanType()
     kind = "boolean"
 
     constructor() {}
 
     toConstructor() {
-        return "new BooleanType()"
+        return "BooleanType.instance"
     }
 
     toString() {

compiler/types/NumberType.ts

@@ -1,12 +1,13 @@
 import { Type } from "./Type"
 
 export class NumberType implements Type {
+    static instance = new NumberType()
     kind = "number"
 
     constructor() {}
 
     toConstructor() {
-        return "new NumberType()"
+        return "NumberType.instance"
     }
 
     toString() {

compiler/types/StringType.ts

@@ -1,12 +1,13 @@
 import { Type } from "./Type"
 
 export class StringType implements Type {
+    static instance = new StringType()
     kind = "string"
 
     constructor() {}
 
     toConstructor() {
-        return "new StringType()"
+        return "StringType.instance"
     }
 
     toString() {

compiler/types/VoidType.ts

@@ -1,12 +1,13 @@
 import { Type } from "./Type"
 
 export class VoidType implements Type {
+    static instance = new VoidType()
     kind = "void"
 
     constructor() {}
 
     toConstructor() {
-        return "new VoidType()"
+        return "VoidType.instance"
     }
 
     toString() {