mirror of
https://github.com/tc39/test262.git
synced 2025-07-14 09:34:37 +02:00
ea37a19a4a
* Add tests for nullable quantifiers in RegExps The JavaScript semantics for a quantifier matching the empty string are different from other regex languages. This adds a test that documents this JavaScript-specific behavior. This is part of my work at the SYSTEMF lab at EPFL. * Update nullable-quantifier.js
22 lines
1.2 KiB
JavaScript
22 lines
1.2 KiB
JavaScript
// Copyright (C) 2024 Aurèle Barrière. All rights reserved.
|
|
// This code is governed by the BSD license found in the LICENSE file.
|
|
|
|
/*---
|
|
esid: sec-runtime-semantics-repeatmatcher-abstract-operation
|
|
description: JavaScript nullable quantifiers have special semantics, optional iterations are not allowed to match the empty string. Point 2.b below shows that after each optional (min=0) iteration of a quantifier, if the iteration matched the empty string (y.[[EndIndex]] = x.[[EndIndex]]), then the iteration is discarded. In particular, for (a?b??)* on "ab", it is possible to do two iterations of the star, one matching "a" and the other matching "b".
|
|
info: |
|
|
RepeatMatcher ( m, min, max, greedy, x, c, parenIndex, parenCount )
|
|
|
|
2. Let d be a new MatcherContinuation with parameters (y) that captures m, min, max, greedy, x, c, parenIndex, and parenCount and performs the following steps when called:
|
|
|
|
b. If min = 0 and y.[[EndIndex]] = x.[[EndIndex]], return failure.
|
|
author: Aurèle Barrière
|
|
---*/
|
|
|
|
let input = "ab";
|
|
let regex = /(a?b??)*/;
|
|
let match = regex.exec(input);
|
|
let expected = "ab";
|
|
|
|
assert.sameValue(match[0], expected, "The regex is expected to match the whole string");
|