Binary expression operator overloads for +/==; Check allocation flow in ternary expressions; Cache empty array buffers; Sealed decorator for non-derivable internals

src/compiler.ts

@@ -2672,7 +2672,18 @@ export class Compiler extends DiagnosticEmitter {
             expr = module.createBinary(BinaryOp.EqI32, leftExpr, rightExpr);
             break;
           }
-          case TypeKind.USIZE: // TODO: check operator overload
+          case TypeKind.USIZE: { // check operator overload
+            if (this.currentType.is(TypeFlags.REFERENCE)) {
+              let classInstance = assert(this.currentType.classReference);
+              let operatorName = classInstance.prototype.fnEquals;
+              if (operatorName != null) {
+                expr = this.compileOperatorOverload(classInstance, operatorName, leftExpr, rightExpr);
+                assert(this.currentType == Type.bool);
+                break;
+              }
+            }
+            // fall-through
+          }
           case TypeKind.ISIZE: {
             expr = module.createBinary(
               this.options.isWasm64
@@ -2822,7 +2833,17 @@ export class Compiler extends DiagnosticEmitter {
             expr = module.createBinary(BinaryOp.AddI32, leftExpr, rightExpr);
             break;
           }
-          case TypeKind.USIZE: // TODO: check operator overload
+          case TypeKind.USIZE: { // check operator overload
+            if (this.currentType.is(TypeFlags.REFERENCE)) {
+              let classInstance = assert(this.currentType.classReference);
+              let operatorName = classInstance.prototype.fnConcat;
+              if (operatorName != null) {
+                expr = this.compileOperatorOverload(classInstance, operatorName, leftExpr, rightExpr);
+                break;
+              }
+            }
+            // fall-through
+          }
           case TypeKind.ISIZE: {
             expr = module.createBinary(
               this.options.isWasm64
@@ -3726,6 +3747,20 @@ export class Compiler extends DiagnosticEmitter {
       : expr;
   }
 
+  compileOperatorOverload(
+    classInstance: Class,
+    operatorName: string,
+    leftExpr: ExpressionRef,
+    rightExpr: ExpressionRef
+  ): ExpressionRef {
+    var classPrototype = classInstance.prototype;
+    var operatorPrototype = assert(assert(classPrototype.members).get(operatorName));
+    assert(operatorPrototype.kind == ElementKind.FUNCTION_PROTOTYPE);
+    var operatorInstance = (<FunctionPrototype>operatorPrototype).resolve();
+    if (!operatorInstance) return this.module.createUnreachable();
+    return this.makeCallDirect(operatorInstance, [ leftExpr, rightExpr ]);
+  }
+
   compileAssignment(expression: Expression, valueExpression: Expression, contextualType: Type): ExpressionRef {
     var currentFunction = this.currentFunction;
     var resolved = this.program.resolveExpression(expression, currentFunction); // reports
@@ -4526,7 +4561,6 @@ export class Compiler extends DiagnosticEmitter {
           assert(parent.kind == ElementKind.CLASS);
           let thisType = (<Class>parent).type;
           if (currentFunction.is(CommonFlags.CONSTRUCTOR)) {
-            let nativeSizeType = this.options.nativeSizeType;
             let flow = currentFunction.flow;
             if (!flow.is(FlowFlags.ALLOCATES)) {
               flow.set(FlowFlags.ALLOCATES);
@@ -5152,8 +5186,36 @@ export class Compiler extends DiagnosticEmitter {
         : this.compileExpression(ifElse, contextualType);
     }
 
-    var ifThenExpr = this.compileExpression(ifThen, contextualType);
-    var ifElseExpr = this.compileExpression(ifElse, contextualType);
+    var currentFunction = this.currentFunction;
+    var ifThenExpr: ExpressionRef;
+    var ifElseExpr: ExpressionRef;
+
+    // if part of a constructor, keep track of memory allocations
+    if (currentFunction.is(CommonFlags.CONSTRUCTOR)) {
+      let flow = currentFunction.flow;
+
+      flow = flow.enterBranchOrScope();
+      currentFunction.flow = flow;
+      ifThenExpr = this.compileExpression(ifThen, contextualType);
+      let ifThenAllocates = flow.is(FlowFlags.ALLOCATES);
+      flow = flow.leaveBranchOrScope();
+      currentFunction.flow = flow;
+
+      flow = flow.enterBranchOrScope();
+      currentFunction.flow = flow;
+      ifElseExpr = this.compileExpression(ifElse, contextualType);
+      let ifElseAllocates = flow.is(FlowFlags.ALLOCATES);
+      flow = flow.leaveBranchOrScope();
+      currentFunction.flow = flow;
+
+      if (ifThenAllocates && ifElseAllocates) flow.set(FlowFlags.ALLOCATES);
+
+    // otherwise simplify
+    } else {
+      ifThenExpr = this.compileExpression(ifThen, contextualType);
+      ifElseExpr = this.compileExpression(ifElse, contextualType);
+    }
+
     return this.module.createIf(condExpr, ifThenExpr, ifElseExpr);
   }
 

src/diagnosticMessages.generated.ts

@@ -20,6 +20,7 @@ export enum DiagnosticCode {
   Structs_cannot_implement_interfaces = 208,
   Invalid_regular_expression_flags = 209,
   Implementation_0_must_match_the_signature_1 = 210,
+  Class_0_is_sealed_and_cannot_be_extended = 211,
   Unterminated_string_literal = 1002,
   Identifier_expected = 1003,
   _0_expected = 1005,
@@ -122,6 +123,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 208: return "Structs cannot implement interfaces.";
     case 209: return "Invalid regular expression flags.";
     case 210: return "Implementation '{0}' must match the signature '{1}'.";
+    case 211: return "Class '{0}' is sealed and cannot be extended.";
     case 1002: return "Unterminated string literal.";
     case 1003: return "Identifier expected.";
     case 1005: return "'{0}' expected.";

src/diagnosticMessages.json

@@ -12,6 +12,7 @@
   "Structs cannot implement interfaces.": 208,
   "Invalid regular expression flags.": 209,
   "Implementation '{0}' must match the signature '{1}'.": 210,
+  "Class '{0}' is sealed and cannot be extended.": 211,
 
   "Unterminated string literal.": 1002,
   "Identifier expected.": 1003,

src/parser.ts

@@ -171,6 +171,10 @@ export class Parser extends DiagnosticEmitter {
           flags |= CommonFlags.UNMANAGED;
           continue;
         }
+        if (text == "sealed") {
+          flags |= CommonFlags.SEALED;
+          continue;
+        }
       }
       if (!decorators) decorators = [];
       decorators.push(decorator);

src/program.ts

@@ -2041,34 +2041,36 @@ export enum CommonFlags {
   BUILTIN = 1 << 14,
   /** Is unmanaged. */
   UNMANAGED = 1 << 15,
+  /** Is sealed. */
+  SEALED = 1 << 16,
 
   // Extended modifiers usually derived from basic modifiers or internal decorators
 
   /** Is ambient, that is either declared or nested in a declared element. */
-  AMBIENT = 1 << 16,
+  AMBIENT = 1 << 17,
   /** Is generic. */
-  GENERIC = 1 << 17,
+  GENERIC = 1 << 18,
   /** Is part of a generic context. */
-  GENERIC_CONTEXT = 1 << 18,
+  GENERIC_CONTEXT = 1 << 19,
   /** Is an instance member. */
-  INSTANCE = 1 << 19,
+  INSTANCE = 1 << 20,
   /** Is a constructor. */
-  CONSTRUCTOR = 1 << 20,
+  CONSTRUCTOR = 1 << 21,
   /** Is an arrow function. */
-  ARROW = 1 << 21,
+  ARROW = 1 << 22,
   /** Is a module export. */
-  MODULE_EXPORT = 1 << 22,
+  MODULE_EXPORT = 1 << 23,
   /** Is a module import. */
-  MODULE_IMPORT = 1 << 23,
+  MODULE_IMPORT = 1 << 24,
 
   // Compilation states
 
   /** Is compiled. */
-  COMPILED = 1 << 24,
+  COMPILED = 1 << 25,
   /** Has a constant value and is therefore inlined. */
-  INLINED = 1 << 25,
+  INLINED = 1 << 26,
   /** Is scoped. */
-  SCOPED = 1 << 26
+  SCOPED = 1 << 27
 }
 
 /** Base class of all program elements. */
@@ -2873,6 +2875,13 @@ export class ClassPrototype extends Element {
         );
         return null;
       }
+      if (baseClass.is(CommonFlags.SEALED)) {
+        this.program.error(
+          DiagnosticCode.Class_0_is_sealed_and_cannot_be_extended,
+          declaration.extendsType.range, baseClass.internalName
+        );
+        return null;
+      }
       if (baseClass.prototype.is(CommonFlags.UNMANAGED) != this.is(CommonFlags.UNMANAGED)) {
         this.program.error(
           DiagnosticCode.Structs_cannot_extend_classes_and_vice_versa,