| // Copyright (C) 2016 the V8 project authors. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| /*--- |
| esid: sec-regular-expressions-patterns |
| es6id: B.1.4 |
| description: Quantifiable assertions `?=` ("followed by") |
| info: | |
| Term[U] :: |
| [~U] QuantifiableAssertion Quantifier |
| |
| QuantifiableAssertion :: |
| ( ?= Disjunction ) |
| ( ?! Disjunction ) |
| |
| The production Term::QuantifiableAssertionQuantifier evaluates the same as |
| the production Term::AtomQuantifier but with QuantifiableAssertion |
| substituted for Atom. |
| |
| The production Assertion::QuantifiableAssertion evaluates by evaluating |
| QuantifiableAssertion to obtain a Matcher and returning that Matcher. |
| |
| Assertion (21.2.2.6) evaluation rules for the Assertion::(?=Disjunction) |
| and Assertion::(?!Disjunction) productions are also used for the |
| QuantifiableAssertion productions, but with QuantifiableAssertion |
| substituted for Assertion. |
| ---*/ |
| |
| var match; |
| |
| match = /.(?=Z)*/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'a', 'quantifier: *'); |
| |
| match = /.(?=Z)+/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: +'); |
| |
| match = /.(?=Z)?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'a', 'quantifier: ?'); |
| |
| match = /.(?=Z){2}/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: { DecimalDigits }'); |
| |
| match = /.(?=Z){2,}/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: { DecimalDigits , }'); |
| |
| match = /.(?=Z){2,3}/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue( |
| match[0], 'b', 'quantifier: { DecimalDigits , DecimalDigits }' |
| ); |
| |
| match = /.(?=Z)*?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'a', 'quantifier: * ?'); |
| |
| match = /.(?=Z)+?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: + ?'); |
| |
| match = /.(?=Z)??/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'a', 'quantifier: ? ?'); |
| |
| match = /.(?=Z){2}?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: { DecimalDigits } ?'); |
| |
| match = /.(?=Z){2,}?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue(match[0], 'b', 'quantifier: { DecimalDigits , } ?'); |
| |
| match = /.(?=Z){2,3}?/.exec('a bZ cZZ dZZZ eZZZZ'); |
| assert.sameValue( |
| match[0], 'b', 'quantifier: { DecimalDigits , DecimalDigits } ?' |
| ); |