Support a bit more interface syntax when parsing, see #160

src/diagnosticMessages.generated.ts

@@ -76,6 +76,7 @@ export enum DiagnosticCode {
   Unterminated_Unicode_escape_sequence = 1199,
   Decorators_are_not_valid_here = 1206,
   _abstract_modifier_can_only_appear_on_a_class_method_or_property_declaration = 1242,
+  Method_0_cannot_have_an_implementation_because_it_is_marked_abstract = 1245,
   A_class_may_only_extend_another_class = 1311,
   A_parameter_property_cannot_be_declared_using_a_rest_parameter = 1317,
   Duplicate_identifier_0 = 2300,
@@ -188,6 +189,7 @@ export function diagnosticCodeToString(code: DiagnosticCode): string {
     case 1199: return "Unterminated Unicode escape sequence.";
     case 1206: return "Decorators are not valid here.";
     case 1242: return "'abstract' modifier can only appear on a class, method, or property declaration.";
+    case 1245: return "Method '{0}' cannot have an implementation because it is marked abstract.";
     case 1311: return "A class may only extend another class.";
     case 1317: return "A parameter property cannot be declared using a rest parameter.";
     case 2300: return "Duplicate identifier '{0}'.";

src/diagnosticMessages.json

@@ -69,6 +69,7 @@
   "Unterminated Unicode escape sequence.": 1199,
   "Decorators are not valid here.": 1206,
   "'abstract' modifier can only appear on a class, method, or property declaration.": 1242,
+  "Method '{0}' cannot have an implementation because it is marked abstract.": 1245,
   "A class may only extend another class.": 1311,
   "A parameter property cannot be declared using a rest parameter.": 1317,
 

src/parser.ts

@@ -82,7 +82,8 @@ import {
 
   mangleInternalPath,
   nodeIsCallable,
-  nodeIsGenericCallable
+  nodeIsGenericCallable,
+  InterfaceDeclaration
 } from "./ast";
 
 const builtinsFile = LIBRARY_PREFIX + "builtins.ts";
@@ -1556,21 +1557,50 @@ export class Parser extends DiagnosticEmitter {
     //   Identifier ...
 
     var startPos = tn.pos;
+    var isInterface = parent.kind == NodeKind.INTERFACEDECLARATION;
 
     var decorators = new Array<DecoratorNode>();
     while (tn.skip(Token.AT)) {
       let decorator = this.parseDecorator(tn);
       if (!decorator) break;
+      if (isInterface) {
+        this.error(
+          DiagnosticCode.Decorators_are_not_valid_here,
+          decorator.range
+        );
+      }
       decorators.push(<DecoratorNode>decorator);
     }
 
-    var flags = parent.flags & CommonFlags.AMBIENT; // inherit
+    // inherit ambient status
+    var flags = parent.flags & CommonFlags.AMBIENT;
+
+    // implemented methods are virtual
+    if (isInterface) flags |= CommonFlags.VIRTUAL;
 
     if (tn.skip(Token.PUBLIC)) {
+      if (isInterface) {
+        this.error(
+          DiagnosticCode._0_modifier_cannot_be_used_here,
+          tn.range(), "public"
+        );
+      }
       flags |= CommonFlags.PUBLIC;
     } else if (tn.skip(Token.PRIVATE)) {
+      if (isInterface) {
+        this.error(
+          DiagnosticCode._0_modifier_cannot_be_used_here,
+          tn.range(), "private"
+        );
+      }
       flags |= CommonFlags.PRIVATE;
     } else if (tn.skip(Token.PROTECTED)) {
+      if (isInterface) {
+        this.error(
+          DiagnosticCode._0_modifier_cannot_be_used_here,
+          tn.range(), "protected"
+        );
+      }
       flags |= CommonFlags.PROTECTED;
     }
 
@@ -1579,16 +1609,27 @@ export class Parser extends DiagnosticEmitter {
     var abstractStart: i32 = 0;
     var abstractEnd: i32 = 0;
     if (tn.skip(Token.STATIC)) {
+      if (isInterface) {
+        this.error(
+          DiagnosticCode._0_modifier_cannot_be_used_here,
+          tn.range(), "static"
+        );
+      }
       flags |= CommonFlags.STATIC;
       staticStart = tn.tokenPos;
       staticEnd = tn.pos;
     } else {
+      flags |= CommonFlags.INSTANCE;
       if (tn.skip(Token.ABSTRACT)) {
-        flags |= (CommonFlags.ABSTRACT | CommonFlags.INSTANCE);
+        if (isInterface) {
+          this.error(
+            DiagnosticCode._0_modifier_cannot_be_used_here,
+            tn.range(), "abstract"
+          );
+        }
+        flags |= CommonFlags.ABSTRACT;
         abstractStart = tn.tokenPos;
         abstractEnd = tn.pos;
-      } else {
-        flags |= CommonFlags.INSTANCE;
       }
       if (parent.flags & CommonFlags.GENERIC) {
         flags |= CommonFlags.GENERIC_CONTEXT;
@@ -1612,6 +1653,7 @@ export class Parser extends DiagnosticEmitter {
     var isSetter = false;
     var setStart: i32 = 0;
     var setEnd: i32 = 0;
+    if (!isInterface) {
       if (tn.skip(Token.GET)) {
         if (tn.peek(true, IdentifierHandling.PREFER) == Token.IDENTIFIER && !tn.nextTokenOnNewLine) {
           flags |= CommonFlags.GET;
@@ -1664,6 +1706,7 @@ export class Parser extends DiagnosticEmitter {
           ); // recoverable
         }
       }
+    }
 
     if (!isConstructor && !tn.skipIdentifier()) {
       this.error(
@@ -1787,10 +1830,15 @@ export class Parser extends DiagnosticEmitter {
             DiagnosticCode.An_implementation_cannot_be_declared_in_ambient_contexts,
             tn.range()
           ); // recoverable
+        } else if (flags & CommonFlags.ABSTRACT) {
+          this.error(
+            DiagnosticCode.Method_0_cannot_have_an_implementation_because_it_is_marked_abstract,
+            tn.range(), name.text
+          ); // recoverable
         }
         body = this.parseBlockStatement(tn, false);
         if (!body) return null;
-      } else if (!(flags & CommonFlags.AMBIENT)) {
+      } else if (!(flags & CommonFlags.AMBIENT) && !isInterface) {
         this.error(
           DiagnosticCode.Function_implementation_is_missing_or_not_immediately_following_the_declaration,
           tn.range()

src/program.ts

@@ -775,6 +775,12 @@ export class Program extends DiagnosticEmitter {
 
       // remember classes that implement interfaces
       } else if (numImplementsTypes) {
+        for (let i = 0; i < numImplementsTypes; ++i) {
+          this.warning( // TODO
+            DiagnosticCode.Operation_not_supported,
+            implementsTypes[i].range
+          );
+        }
         queuedImplements.push(prototype);
       }
     }
@@ -2094,32 +2100,27 @@ export class Program extends DiagnosticEmitter {
     var element: Element | null;
 
     if (context) {
-      let parent: Element | null;
 
       switch (context.kind) {
-        case ElementKind.FUNCTION: { // search locals
+        case ElementKind.FUNCTION: { // search locals, use prototype
           element = (<Function>context).flow.getScopedLocal(name);
           if (element) {
             this.resolvedThisExpression = null;
             this.resolvedElementExpression = null;
             return element;
           }
-          parent = (<Function>context).prototype.parent;
+          context = (<Function>context).prototype.parent;
           break;
         }
-        case ElementKind.CLASS: {
+        case ElementKind.CLASS: { // use prototype
-          parent = (<Class>context).prototype.parent;
+          context = (<Class>context).prototype.parent;
-          break;
-        }
-        default: {
-          parent = context;
           break;
         }
       }
 
-      // search parent
+      // search context
-      while (parent) {
+      while (context) {
-        let members = parent.members;
+        let members = context.members;
         if (members) {
           if (element = members.get(name)) {
             this.resolvedThisExpression = null;
@@ -2127,7 +2128,7 @@ export class Program extends DiagnosticEmitter {
             return element;
           }
         }
-        parent = parent.parent;
+        context = context.parent;
       }
     }
 

tests/parser/interface.ts

@@ -0,0 +1,5 @@
+interface Foo {
+  bar(): void;
+  baz: i32;
+  readonly baz2: f64;
+}

tests/parser/interface.ts.fixture.ts

@@ -0,0 +1,5 @@
+interface Foo {
+  bar(): void;
+  baz: i32;
+  readonly baz2: f64;
+}