Switch signature help over to using display parts. This allows for classified sig help on the editor side.

src/harness/fourslash.ts

@@ -820,7 +820,14 @@ module FourSlash {
             this.taoInvalidReason = 'verifyCurrentSignatureHelpIs NYI';
 
             var help = this.getActiveSignatureHelpItem();
-            assert.equal(help.prefix + help.parameters.map(p => p.display).join(help.separator) + help.suffix, expected);
+            assert.equal(
+                this.partsToString(help.prefixDisplayParts) + 
+                help.parameters.map(p => this.partsToString(p.displayParts)).join(this.partsToString(help.separatorDisplayParts)) + 
+                this.partsToString(help.suffixDisplayParts), expected);
+        }
+
+        private partsToString(parts: ts.SymbolDisplayPart[]): string {
+            return parts.map(p => p.text).join("");
         }
 
         public verifyCurrentParameterIsVariable(isVariable: boolean) {
@@ -844,7 +851,7 @@ module FourSlash {
 
             var activeSignature = this.getActiveSignatureHelpItem();
             var activeParameter = this.getActiveParameter();
-            assert.equal(activeParameter.display, parameter);
+            assert.equal(this.partsToString(activeParameter.displayParts), parameter);
         }
 
         public verifyCurrentParameterHelpDocComment(docComment: string) {

src/services/services.ts

@@ -856,8 +856,8 @@ module ts {
 
     export class SignatureHelpParameter {
         constructor(public name: string,
-                    public documentation: string,
-                    public display: string,
+                    public documentation: SymbolDisplayPart[],
+                    public displayParts: SymbolDisplayPart[],
                     public isOptional: boolean) {
         }
     }
@@ -871,11 +871,11 @@ module ts {
      */
     export class SignatureHelpItem {
         constructor(public isVariadic: boolean,
-                    public prefix: string,
-                    public suffix: string,
-                    public separator: string,
+                    public prefixDisplayParts: SymbolDisplayPart[],
+                    public suffixDisplayParts: SymbolDisplayPart[],
+                    public separatorDisplayParts: SymbolDisplayPart[],
                     public parameters: SignatureHelpParameter[],
-                    public documentation: string) {
+                    public documentation: SymbolDisplayPart[]) {
         }
     }
 
@@ -1630,6 +1630,11 @@ module ts {
         });
     }
 
+    export function getSymbolDocumentationDisplayParts(symbol: Symbol): SymbolDisplayPart[] {
+        var documentation = symbol.getDocumentationComment();
+        return documentation === "" ? [] : [new SymbolDisplayPart(documentation, SymbolDisplayPartKind.text, /*symbol:*/ null)];
+    }
+
     export function createLanguageService(host: LanguageServiceHost, documentRegistry: DocumentRegistry): LanguageService {
         var syntaxTreeCache: SyntaxTreeCache = new SyntaxTreeCache(host);
         var formattingRulesProvider: TypeScript.Services.Formatting.RulesProvider;
@@ -2376,8 +2381,7 @@ module ts {
                 return undefined;
             }
 
-            var documentation = symbol.getDocumentationComment();
-            var documentationParts = documentation === "" ? [] : [new SymbolDisplayPart(documentation, SymbolDisplayPartKind.text, /*symbol:*/ null)];
+            var documentationParts = getSymbolDocumentationDisplayParts(symbol);
 
             // Having all this logic here is pretty unclean.  Consider moving to the roslyn model
             // where all symbol display logic is encapsulated into visitors and options.
@@ -3731,9 +3735,9 @@ module ts {
 
             // Reset writer back to undefined to make sure that we produce an error message if CompilerHost.writeFile method is called when we are not in getEmitOutput
             writer = undefined;
-            return emitOutput;
-        }
-
+            return emitOutput;
+        }
+
         // Signature help
         /**
          * This is a semantic operation.

src/services/signatureHelp.ts

@@ -252,29 +252,66 @@ module ts.SignatureHelp {
             var items = map(candidates, candidateSignature => {
                 var parameters = candidateSignature.parameters;
                 var parameterHelpItems = parameters.length === 0 ? emptyArray : map(parameters, p => {
-                    var display = p.name;
+                    var displayParts: SymbolDisplayPart[] = [];
+
                     if (candidateSignature.hasRestParameter && parameters[parameters.length - 1] === p) {
-                        display = "..." + display;
+                        displayParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.DotDotDotToken), SymbolDisplayPartKind.punctuation, undefined));
                     }
+
+                    displayParts.push(new SymbolDisplayPart(p.name, SymbolDisplayPartKind.parameterName, p));
+
                     var isOptional = !!(p.valueDeclaration.flags & NodeFlags.QuestionMark);
                     if (isOptional) {
-                        display += "?";
+                        displayParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.QuestionToken), SymbolDisplayPartKind.punctuation, undefined));
                     }
-                    display += ": " + typeInfoResolver.typeToString(typeInfoResolver.getTypeOfSymbol(p), argumentListOrTypeArgumentList);
-                    return new SignatureHelpParameter(p.name, "", display, isOptional);
+
+                    displayParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.ColonToken), SymbolDisplayPartKind.punctuation, undefined));
+                    displayParts.push(new SymbolDisplayPart(" ", SymbolDisplayPartKind.space, undefined));
+
+                    var typeParts = typeInfoResolver.typeToDisplayParts(typeInfoResolver.getTypeOfSymbol(p), argumentListOrTypeArgumentList);
+                    displayParts.push.apply(displayParts, typeParts);
+
+                    return new SignatureHelpParameter(p.name, getSymbolDocumentationDisplayParts(p), displayParts, isOptional);
                 });
+
                 var callTargetNode = (<CallExpression>argumentListOrTypeArgumentList.parent).func;
                 var callTargetSymbol = typeInfoResolver.getSymbolInfo(callTargetNode);
-                var signatureName = callTargetSymbol ? typeInfoResolver.symbolToString(callTargetSymbol, /*enclosingDeclaration*/ undefined, /*meaning*/ undefined) : "";
-                var prefix = signatureName;
+
+                var prefixParts = callTargetSymbol ? typeInfoResolver.symbolToDisplayParts(callTargetSymbol, /*enclosingDeclaration*/ undefined, /*meaning*/ undefined) : [];
+
+                var separatorParts = [
+                    new SymbolDisplayPart(tokenToString(SyntaxKind.CommaToken), SymbolDisplayPartKind.punctuation, undefined),
+                    new SymbolDisplayPart(" ", SymbolDisplayPartKind.space, undefined)
+                ];
+
                 // TODO(jfreeman): Constraints?
                 if (candidateSignature.typeParameters && candidateSignature.typeParameters.length) {
-                    prefix += "<" + map(candidateSignature.typeParameters, tp => tp.symbol.name).join(", ") + ">";
+                    prefixParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.LessThanToken), SymbolDisplayPartKind.punctuation, undefined));
+
+                    for (var i = 0, n = candidateSignature.typeParameters.length; i < n; i++) {
+                        if (i) {
+                            prefixParts.push.apply(prefixParts, separatorParts);
+                        }
+
+                        var tp = candidateSignature.typeParameters[i].symbol;
+                        prefixParts.push(new SymbolDisplayPart(tp.name, SymbolDisplayPartKind.typeParameterName, tp));
+                    }
+
+                    prefixParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.GreaterThanToken), SymbolDisplayPartKind.punctuation, undefined));
                 }
-                prefix += "(";
-                var suffix = "): " + typeInfoResolver.typeToString(candidateSignature.getReturnType(), argumentListOrTypeArgumentList);
-                return new SignatureHelpItem(candidateSignature.hasRestParameter, prefix, suffix, ", ", parameterHelpItems, "");
+
+                prefixParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.OpenParenToken), SymbolDisplayPartKind.punctuation, undefined));
+
+                var suffixParts = [new SymbolDisplayPart(tokenToString(SyntaxKind.CloseParenToken), SymbolDisplayPartKind.punctuation, undefined)];
+                suffixParts.push(new SymbolDisplayPart(tokenToString(SyntaxKind.ColonToken), SymbolDisplayPartKind.punctuation, undefined));
+                suffixParts.push(new SymbolDisplayPart(" ", SymbolDisplayPartKind.space, undefined));
+
+                var typeParts = typeInfoResolver.typeToDisplayParts(candidateSignature.getReturnType(), argumentListOrTypeArgumentList);
+                suffixParts.push.apply(suffixParts, typeParts);
+                
+                return new SignatureHelpItem(candidateSignature.hasRestParameter, prefixParts, suffixParts, separatorParts, parameterHelpItems, null);
             });
+
             var selectedItemIndex = candidates.indexOf(bestSignature);
             if (selectedItemIndex < 0) {
                 selectedItemIndex = 0;
@@ -339,11 +376,11 @@ module ts.SignatureHelp {
         // by 2 to exclude commas. Use bit shifting in order to take the floor of the division.
         var argumentIndex = indexOfNodeContainingPosition < 0 ? argumentCount - 1 : indexOfNodeContainingPosition >> 1;
         return new SignatureHelpState(argumentIndex, argumentCount);
-    }
-
-    function getChildListThatStartsWithOpenerToken(parent: Node, openerToken: Node, sourceFile: SourceFile): Node {
+    }
+
+    function getChildListThatStartsWithOpenerToken(parent: Node, openerToken: Node, sourceFile: SourceFile): Node {
         var children = parent.getChildren(sourceFile);
         var indexOfOpenerToken = children.indexOf(openerToken);
-        return children[indexOfOpenerToken + 1];
+        return children[indexOfOpenerToken + 1];
     }
 }

tests/cases/fourslash/signatureHelpSuperConstructorOverload.ts

@@ -17,6 +17,7 @@
 ////    }
 ////}
 
+debugger;
 goTo.marker('superOverload1');
 verify.signatureHelpCountIs(2);
 verify.currentSignatureHelpIs("SuperOverloadlBase(): SuperOverloadlBase");