Type aliases

src/builtins.ts

@@ -54,6 +54,10 @@ export function initialize(program: Program): void {
   addFunction(program, "assert");
 
   // conversions and limits
+  let i32Func: FunctionPrototype,
+      u32Func: FunctionPrototype,
+      i64Func: FunctionPrototype,
+      u64Func: FunctionPrototype;
   addFunction(program, "i8").members = new Map([
     [ "MIN_VALUE", new Global(program, "i8.MIN_VALUE", null, Type.i8).withConstantIntegerValue(-128, -1) ],
     [ "MAX_VALUE", new Global(program, "i8.MAX_VALUE", null, Type.i8).withConstantIntegerValue(127, 0) ]
@@ -62,11 +66,11 @@ export function initialize(program: Program): void {
     [ "MIN_VALUE", new Global(program, "i16.MIN_VALUE", null, Type.i16).withConstantIntegerValue(-32768, -1) ],
     [ "MAX_VALUE", new Global(program, "i16.MAX_VALUE", null, Type.i16).withConstantIntegerValue(32767, 0) ]
   ]);
-  addFunction(program, "i32").members = new Map([
+  (i32Func = addFunction(program, "i32")).members = new Map([
     [ "MIN_VALUE", new Global(program, "i32.MIN_VALUE", null, Type.i32).withConstantIntegerValue(-2147483648, -1) ],
     [ "MAX_VALUE", new Global(program, "i32.MAX_VALUE", null, Type.i32).withConstantIntegerValue(2147483647, 0) ]
   ]);
-  addFunction(program, "i64").members = new Map([
+  (i64Func = addFunction(program, "i64")).members = new Map([
     [ "MIN_VALUE", new Global(program, "i64.MIN_VALUE", null, Type.i64).withConstantIntegerValue(0, -2147483648) ],
     [ "MAX_VALUE", new Global(program, "i64.MAX_VALUE", null, Type.i64).withConstantIntegerValue(-1, 2147483647) ]
   ]);
@@ -78,11 +82,11 @@ export function initialize(program: Program): void {
     [ "MIN_VALUE", new Global(program, "u16.MIN_VALUE", null, Type.u16).withConstantIntegerValue(0, 0) ],
     [ "MAX_VALUE", new Global(program, "u16.MAX_VALUE", null, Type.u16).withConstantIntegerValue(65535, 0) ]
   ]);
-  addFunction(program, "u32").members = new Map([
+  (u32Func = addFunction(program, "u32")).members = new Map([
     [ "MIN_VALUE", new Global(program, "u32.MIN_VALUE", null, Type.u32).withConstantIntegerValue(0, 0) ],
     [ "MAX_VALUE", new Global(program, "u32.MAX_VALUE", null, Type.u32).withConstantIntegerValue(-1, 0) ]
   ]);
-  addFunction(program, "u64").members = new Map([
+  (u64Func = addFunction(program, "u64")).members = new Map([
     [ "MIN_VALUE", new Global(program, "u64.MIN_VALUE", null, Type.u64).withConstantIntegerValue(0, 0) ],
     [ "MAX_VALUE", new Global(program, "u64.MAX_VALUE", null, Type.i64).withConstantIntegerValue(-1, -1) ]
   ]);
@@ -99,12 +103,12 @@ export function initialize(program: Program): void {
     [ "MAX_SAFE_INTEGER", new Global(program, "f64.MAX_SAFE_INTEGER", null, Type.f64).withConstantFloatValue(9007199254740991) ]
   ]);
   if (program.target == Target.WASM64) {
-    program.elements.set("isize", <Element>program.elements.get("i64"));
+    program.elements.set("isize", i64Func);
-    program.elements.set("usize", <Element>program.elements.get("u64"));
+    program.elements.set("usize", u64Func);
     addConstant(program, "HEAP_BASE", Type.usize64);
   } else {
-    program.elements.set("isize", <Element>program.elements.get("i32"));
+    program.elements.set("isize", i32Func);
-    program.elements.set("usize", <Element>program.elements.get("u32"));
+    program.elements.set("usize", u32Func);
     addConstant(program, "HEAP_BASE", Type.usize32);
   }
 }

src/compiler.ts

@@ -769,12 +769,18 @@ export class Compiler extends DiagnosticEmitter {
       case NodeKind.TRY:
         return this.compileTryStatement(<TryStatement>statement);
 
+      case NodeKind.TYPEDECLARATION:
+        if (this.currentFunction == this.startFunction)
+          return this.module.createNop();
+        break; // must be top-level; function bodies are not initialized
+
       case NodeKind.VARIABLE:
         return this.compileVariableStatement(<VariableStatement>statement);
 
       case NodeKind.WHILE:
         return this.compileWhileStatement(<WhileStatement>statement);
     }
+    this.error(DiagnosticCode.Operation_not_supported, statement.range);
     throw new Error("unexpected statement kind");
   }
 

src/program.ts

@@ -76,6 +76,8 @@ export class Program extends DiagnosticEmitter {
   elements: Map<string,Element> = new Map();
   /** Types by internal name. */
   types: Map<string,Type> = noTypesYet;
+  /** Declared type aliases. */
+  typeAliases: Map<string,TypeNode> = new Map();
   /** Exports of individual files by internal name. Not global exports. */
   exports: Map<string,Element> = new Map();
 
@@ -663,12 +665,11 @@ export class Program extends DiagnosticEmitter {
   private initializeType(declaration: TypeDeclaration, namespace: Element | null = null): void {
     // type aliases are program globals
     const name: string = declaration.name.name;
-    if (this.types.has(name)) {
+    if (this.types.has(name) || this.typeAliases.has(name)) {
       this.error(DiagnosticCode.Duplicate_identifier_0, declaration.name.range, name);
       return;
     }
-    // TODO: queue, then resolve
+    this.typeAliases.set(name, declaration.alias);
-    throw new Error("not implemented");
   }
 
   private initializeVariables(statement: VariableStatement, namespace: Element | null = null): void {
@@ -741,6 +742,11 @@ export class Program extends DiagnosticEmitter {
     if (type = <Type | null>this.types.get(globalName))
       return type;
 
+    // check type alias
+    let alias: TypeNode | null = <TypeNode | null>this.typeAliases.get(globalName);
+    if (alias && (type = this.resolveType(alias, null, reportNotFound)))
+      return type;
+
     if (reportNotFound)
       this.error(DiagnosticCode.Cannot_find_name_0, node.identifier.range, globalName);
 

tests/compiler/typealias.optimized.wast

@@ -0,0 +1,14 @@
+(module
+ (type $ii (func (param i32) (result i32)))
+ (type $v (func))
+ (memory $0 1)
+ (export "alias" (func $typealias/alias))
+ (export "memory" (memory $0))
+ (start $start)
+ (func $typealias/alias (; 0 ;) (type $ii) (param $0 i32) (result i32)
+  (get_local $0)
+ )
+ (func $start (; 1 ;) (type $v)
+  (nop)
+ )
+)

tests/compiler/typealias.ts

@@ -0,0 +1,5 @@
+type alias = i32;
+
+export function alias(a: alias): alias {
+  return a;
+}

tests/compiler/typealias.wast

@@ -0,0 +1,67 @@
+(module
+ (type $ii (func (param i32) (result i32)))
+ (type $v (func))
+ (global $HEAP_BASE i32 (i32.const 4))
+ (memory $0 1)
+ (export "alias" (func $typealias/alias))
+ (export "memory" (memory $0))
+ (start $start)
+ (func $typealias/alias (; 0 ;) (type $ii) (param $0 i32) (result i32)
+  (return
+   (get_local $0)
+  )
+ )
+ (func $start (; 1 ;) (type $v)
+  (nop)
+ )
+)
+(;
+[program.elements]
+  NaN
+  Infinity
+  isNaN
+  isFinite
+  clz
+  ctz
+  popcnt
+  rotl
+  rotr
+  abs
+  max
+  min
+  ceil
+  floor
+  copysign
+  nearest
+  reinterpret
+  sqrt
+  trunc
+  load
+  store
+  sizeof
+  select
+  unreachable
+  current_memory
+  grow_memory
+  parseInt
+  parseFloat
+  changetype
+  assert
+  i8
+  i16
+  i32
+  i64
+  u8
+  u16
+  u32
+  u64
+  bool
+  f32
+  f64
+  isize
+  usize
+  HEAP_BASE
+  typealias/alias
+[program.exports]
+  typealias/alias
+;)