add option to allow for weak match as first match, use that option for outline (experiment) #50724

src/vs/base/common/filters.ts

@@ -454,7 +454,7 @@ const enum Arrow { Top = 0b1, Diag = 0b10, Left = 0b100 }
 
 export type FuzzyScore = [number, number[]];
 
-export function fuzzyScore(pattern: string, word: string, patternMaxWhitespaceIgnore?: number): FuzzyScore {
+export function fuzzyScore(pattern: string, word: string, patternMaxWhitespaceIgnore?: number, firstMatchCanBeWeak?: boolean): FuzzyScore {
 
 	const patternLen = pattern.length > 100 ? 100 : pattern.length;
 	const wordLen = word.length > 100 ? 100 : word.length;
@@ -578,6 +578,7 @@ export function fuzzyScore(pattern: string, word: string, patternMaxWhitespaceIg
 	_matchesCount = 0;
 	_topScore = -100;
 	_patternStartPos = patternStartPos;
+	_firstMatchCanBeWeak = firstMatchCanBeWeak;
 	_findAllMatches(patternLen, wordLen, patternLen === wordLen ? 1 : 0, new LazyArray(), false);
 
 	if (_matchesCount === 0) {
@@ -591,6 +592,7 @@ let _matchesCount: number = 0;
 let _topMatch: LazyArray;
 let _topScore: number = 0;
 let _patternStartPos: number = 0;
+let _firstMatchCanBeWeak: boolean = false;
 
 function _findAllMatches(patternPos: number, wordPos: number, total: number, matches: LazyArray, lastMatched: boolean): void {
 
@@ -644,7 +646,7 @@ function _findAllMatches(patternPos: number, wordPos: number, total: number, mat
 			if (score === 1) {
 				simpleMatchCount += 1;
 
-				if (patternPos === _patternStartPos) {
+				if (patternPos === _patternStartPos && !_firstMatchCanBeWeak) {
 					// when the first match is a weak
 					// match we discard it
 					return undefined;

src/vs/base/test/common/filters.test.ts

@@ -309,6 +309,14 @@ suite('Filters', () => {
 		assertMatches('fo', 'bar\\foo', 'bar\\^f^oo', fuzzyScore);
 	});
 
+	test('fuzzyScore (first match can be weak)', function () {
+		let fuzzyScoreWeak = (pattern, word) => fuzzyScore(pattern, word, undefined, true);
+		assertMatches('Three', 'HTMLHRElement', 'H^TML^H^R^El^ement', fuzzyScoreWeak);
+		assertMatches('tor', 'constructor', 'construc^t^o^r', fuzzyScoreWeak);
+		assertMatches('ur', 'constructor', 'constr^ucto^r', fuzzyScoreWeak);
+		assertTopScore(fuzzyScoreWeak, 'tor', 2, 'constructor', 'Thor', 'cTor');
+	});
+
 	test('fuzzyScore, many matches', function () {
 
 		assertMatches(

src/vs/workbench/parts/outline/electron-browser/outlineModel.ts

@@ -105,7 +105,7 @@ export class OutlineGroup extends TreeElement {
 	}
 
 	private _updateMatches(pattern: string, item: OutlineElement, topMatch: OutlineElement): OutlineElement {
-		item.score = fuzzyScore(pattern, item.symbol.name);
+		item.score = fuzzyScore(pattern, item.symbol.name, undefined, true);
 		if (item.score && (!topMatch || item.score[0] > topMatch.score[0])) {
 			topMatch = item;
 		}