From d8495c31ad75c1ffefbe0cd2a5b085469ae4fb68 Mon Sep 17 00:00:00 2001 From: Jordan Harband Date: Sun, 20 Oct 2024 20:54:21 -0700 Subject: [PATCH] Normative: add `RegExp.escape` (#3382) --- spec.html | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/spec.html b/spec.html index ef6053e6d4..37337c7a8f 100644 --- a/spec.html +++ b/spec.html @@ -37965,6 +37965,64 @@

Properties of the RegExp Constructor

  • has the following properties:
    • + +

    RegExp.escape ( _S_ )

    +

    This function returns a copy of _S_ in which characters that are potentially special in a regular expression |Pattern| have been replaced by equivalent escape sequences.

    +

    It performs the following steps when called:

    + + + 1. If _S_ is not a String, throw a *TypeError* exception. + 1. Let _escaped_ be the empty String. + 1. Let _cpList_ be StringToCodePoints(_S_). + 1. For each code point _c_ of _cpList_, do + 1. If _escaped_ is the empty String and _c_ is matched by either |DecimalDigit| or |AsciiLetter|, then + 1. NOTE: Escaping a leading digit ensures that output corresponds with pattern text which may be used after a `\0` character escape or a |DecimalEscape| such as `\1` and still match _S_ rather than be interpreted as an extension of the preceding escape sequence. Escaping a leading ASCII letter does the same for the context after `\c`. + 1. Let _numericValue_ be the numeric value of _c_. + 1. Let _hex_ be Number::toString(đť”˝(_numericValue_), 16). + 1. Assert: The length of _hex_ is 2. + 1. Set _escaped_ to the string-concatenation of the code unit 0x005C (REVERSE SOLIDUS), *"x"*, and _hex_. + 1. Else, + 1. Set _escaped_ to the string-concatenation of _escaped_ and EncodeForRegExpEscape(_c_). + 1. Return _escaped_. + + + +

    Despite having similar names, EscapeRegExpPattern and `RegExp.escape` do not perform similar actions. The former escapes a pattern for representation as a string, while this function escapes a string for representation inside a pattern.

    +     + + +

    + EncodeForRegExpEscape ( + _c_: a code point, + ): a String +

    +
    +
    description
    +
    It returns a string representing a |Pattern| for matching _c_. If _c_ is white space or an ASCII punctuator, the returned value is an escape sequence. Otherwise, the returned value is a string representation of _c_ itself.
    +
    + + + 1. If _c_ is matched by |SyntaxCharacter| or _c_ is U+002F (SOLIDUS), then + 1. Return the string-concatenation of 0x005C (REVERSE SOLIDUS) and UTF16EncodeCodePoint(_c_). + 1. Else if _c_ is the code point listed in some cell of the “Code Point” column of , then + 1. Return the string-concatenation of 0x005C (REVERSE SOLIDUS) and the string in the “ControlEscape” column of the row whose “Code Point” column contains _c_. + 1. Let _otherPunctuators_ be the string-concatenation of *",-=<>#&!%:;@~'`"* and the code unit 0x0022 (QUOTATION MARK). + 1. Let _toEscape_ be StringToCodePoints(_otherPunctuators_). + 1. If _toEscape_ contains _c_, _c_ is matched by either |WhiteSpace| or |LineTerminator|, or _c_ has the same numeric value as a leading surrogate or trailing surrogate, then + 1. Let _cNum_ be the numeric value of _c_. + 1. If _cNum_ ≤ 0xFF, then + 1. Let _hex_ be Number::toString(𝔽(_cNum_), 16). + 1. Return the string-concatenation of the code unit 0x005C (REVERSE SOLIDUS), *"x"*, and StringPad(_hex_, 2, *"0"*, ~start~). + 1. Let _escaped_ be the empty String. + 1. Let _codeUnits_ be UTF16EncodeCodePoint(_c_). + 1. For each code unit _cu_ of _codeUnits_, do + 1. Set _escaped_ to the string-concatenation of _escaped_ and UnicodeEscape(_cu_). + 1. Return _escaped_. + 1. Return UTF16EncodeCodePoint(_c_). + +     +     +

    RegExp.prototype

    The initial value of `RegExp.prototype` is the RegExp prototype object.