update internal API to allow parameter label to be an offset-range of its the...

update internal API to allow parameter label to be an offset-range of its the signature label, #56337

src/vs/editor/common/modes.ts

@@ -557,7 +557,7 @@ export interface ParameterInformation {
 	 * The label of this signature. Will be shown in
 	 * the UI.
 	 */
-	label: string;
+	label: string | [number, number];
 	/**
 	 * The human-readable doc-comment of this signature. Will be shown
 	 * in the UI but can be omitted.

src/vs/editor/contrib/parameterHints/parameterHints.css

@@ -107,10 +107,6 @@
 	display: block;
 }
 
-.monaco-editor .parameter-hints-widget .signature .parameter {
-	display: inline-block;
-}
-
 .monaco-editor .parameter-hints-widget .signature .parameter.active {
 	font-weight: bold;
 	text-decoration: underline;
@@ -131,4 +127,4 @@
 .monaco-editor.hc-black .parameter-hints-widget .button.next,
 .monaco-editor.vs-dark .parameter-hints-widget .button.next {
 	background-image: url('arrow-down-dark.svg');
-}
\ No newline at end of file
+}

src/vs/editor/contrib/parameterHints/parameterHintsWidget.ts

@@ -432,7 +432,7 @@ export class ParameterHintsWidget implements IContentWidget, IDisposable {
 		this.overloads.textContent = currentOverload;
 
 		if (activeParameter) {
-			const labelToAnnounce = activeParameter.label;
+			const labelToAnnounce = this.getParameterLabel(signature, this.hints.activeParameter);
 			// Select method gets called on every user type while parameter hints are visible.
 			// We do not want to spam the user with same announcements, so we only announce if the current parameter changed.
 
@@ -447,39 +447,41 @@ export class ParameterHintsWidget implements IContentWidget, IDisposable {
 	}
 
 	private renderParameters(parent: HTMLElement, signature: modes.SignatureInformation, currentParameter: number): void {
-		let end = signature.label.length;
-		let idx = 0;
-		let element: HTMLSpanElement;
 
-		for (let i = signature.parameters.length - 1; i >= 0; i--) {
-			const parameter = signature.parameters[i];
-			idx = signature.label.lastIndexOf(parameter.label, end - 1);
+		let [start, end] = this.getParameterLabelOffsets(signature, currentParameter);
 
-			let signatureLabelOffset = 0;
-			let signatureLabelEnd = 0;
+		let beforeSpan = document.createElement('span');
+		beforeSpan.textContent = signature.label.substring(0, start);
 
-			if (idx >= 0) {
-				signatureLabelOffset = idx;
-				signatureLabelEnd = idx + parameter.label.length;
-			}
+		let paramSpan = document.createElement('span');
+		paramSpan.textContent = signature.label.substring(start, end);
+		paramSpan.className = 'parameter active';
 
-			// non parameter part
-			element = document.createElement('span');
-			element.textContent = signature.label.substring(signatureLabelEnd, end);
-			dom.prepend(parent, element);
+		let afterSpan = document.createElement('span');
+		afterSpan.textContent = signature.label.substring(end);
 
-			// parameter part
-			element = document.createElement('span');
-			element.className = `parameter ${i === currentParameter ? 'active' : ''}`;
-			element.textContent = signature.label.substring(signatureLabelOffset, signatureLabelEnd);
-			dom.prepend(parent, element);
+		dom.append(parent, beforeSpan, paramSpan, afterSpan);
+	}
 
-			end = signatureLabelOffset;
+	private getParameterLabel(signature: modes.SignatureInformation, paramIdx: number): string {
+		const param = signature.parameters[paramIdx];
+		if (typeof param.label === 'string') {
+			return param.label;
+		} else {
+			return signature.label.substring(param.label[0], param.label[1]);
+		}
+	}
+
+	private getParameterLabelOffsets(signature: modes.SignatureInformation, paramIdx: number): [number, number] {
+		const param = signature.parameters[paramIdx];
+		if (Array.isArray(param.label)) {
+			return param.label;
+		} else {
+			const idx = signature.label.lastIndexOf(param.label);
+			return idx >= 0
+				? [idx, idx + param.label.length]
+				: [0, 0];
 		}
-		// non parameter part
-		element = document.createElement('span');
-		element.textContent = signature.label.substring(0, end);
-		dom.prepend(parent, element);
 	}
 
 	// private select(position: number): void {

src/vs/monaco.d.ts

@@ -4834,7 +4834,7 @@ declare namespace monaco.languages {
 		 * The label of this signature. Will be shown in
 		 * the UI.
 		 */
-		label: string;
+		label: string | [number, number];
 		/**
 		 * The human-readable doc-comment of this signature. Will be shown
 		 * in the UI but can be omitted.

src/vs/workbench/api/node/extHostTypeConverters.ts

@@ -578,7 +578,7 @@ export namespace ParameterInformation {
 	}
 	export function to(info: modes.ParameterInformation): types.ParameterInformation {
 		return {
-			label: info.label,
+			label: typeof info.label === 'string' ? info.label : '', //todo@joh
 			documentation: htmlContent.isMarkdownString(info.documentation) ? MarkdownString.to(info.documentation) : info.documentation
 		};
 	}