diff options
Diffstat (limited to 'ext/js/general/regex-util.js')
-rw-r--r-- | ext/js/general/regex-util.js | 130 |
1 files changed, 62 insertions, 68 deletions
diff --git a/ext/js/general/regex-util.js b/ext/js/general/regex-util.js index 301b1fcf..f6eca3b6 100644 --- a/ext/js/general/regex-util.js +++ b/ext/js/general/regex-util.js @@ -16,82 +16,76 @@ * along with this program. If not, see <https://www.gnu.org/licenses/>. */ +/** @type {RegExp} @readonly */ +const matchReplacementPattern = /\$(?:\$|&|`|'|(\d\d?)|<([^>]*)>)/g; /** - * This class provides some general utility functions for regular expressions. + * Applies string.replace using a regular expression and replacement string as arguments. + * A source map of the changes is also maintained. + * @param {string} text A string of the text to replace. + * @param {import('./text-source-map.js').TextSourceMap} sourceMap An instance of `TextSourceMap` which corresponds to `text`. + * @param {RegExp} pattern A regular expression to use as the replacement. + * @param {string} replacement A replacement string that follows the format of the standard + * JavaScript regular expression replacement string. + * @returns {string} A new string with the pattern replacements applied and the source map updated. */ -export class RegexUtil { - /** @type {RegExp} @readonly */ - static _matchReplacementPattern = /\$(?:\$|&|`|'|(\d\d?)|<([^>]*)>)/g; +export function applyTextReplacement(text, sourceMap, pattern, replacement) { + const isGlobal = pattern.global; + if (isGlobal) { pattern.lastIndex = 0; } + for (let loop = true; loop; loop = isGlobal) { + const match = pattern.exec(text); + if (match === null) { break; } - /** - * Applies string.replace using a regular expression and replacement string as arguments. - * A source map of the changes is also maintained. - * @param {string} text A string of the text to replace. - * @param {import('./text-source-map.js').TextSourceMap} sourceMap An instance of `TextSourceMap` which corresponds to `text`. - * @param {RegExp} pattern A regular expression to use as the replacement. - * @param {string} replacement A replacement string that follows the format of the standard - * JavaScript regular expression replacement string. - * @returns {string} A new string with the pattern replacements applied and the source map updated. - */ - static applyTextReplacement(text, sourceMap, pattern, replacement) { - const isGlobal = pattern.global; - if (isGlobal) { pattern.lastIndex = 0; } - for (let loop = true; loop; loop = isGlobal) { - const match = pattern.exec(text); - if (match === null) { break; } + const matchText = match[0]; + const index = match.index; + const actualReplacement = applyMatchReplacement(replacement, match); + const actualReplacementLength = actualReplacement.length; + const delta = actualReplacementLength - (matchText.length > 0 ? matchText.length : -1); - const matchText = match[0]; - const index = match.index; - const actualReplacement = this.applyMatchReplacement(replacement, match); - const actualReplacementLength = actualReplacement.length; - const delta = actualReplacementLength - (matchText.length > 0 ? matchText.length : -1); + text = `${text.substring(0, index)}${actualReplacement}${text.substring(index + matchText.length)}`; + pattern.lastIndex += delta; - text = `${text.substring(0, index)}${actualReplacement}${text.substring(index + matchText.length)}`; - pattern.lastIndex += delta; - - if (actualReplacementLength > 0) { - sourceMap.insert(index, ...(new Array(actualReplacementLength).fill(0))); - sourceMap.combine(index - 1 + actualReplacementLength, matchText.length); - } else { - sourceMap.combine(index, matchText.length); - } + if (actualReplacementLength > 0) { + sourceMap.insert(index, ...(new Array(actualReplacementLength).fill(0))); + sourceMap.combine(index - 1 + actualReplacementLength, matchText.length); + } else { + sourceMap.combine(index, matchText.length); } - return text; } + return text; +} - /** - * Applies the replacement string for a given regular expression match. - * @param {string} replacement The replacement string that follows the format of the standard - * JavaScript regular expression replacement string. - * @param {RegExpMatchArray} match A match object returned from RegExp.match. - * @returns {string} A new string with the pattern replacement applied. - */ - static applyMatchReplacement(replacement, match) { - const pattern = this._matchReplacementPattern; - pattern.lastIndex = 0; - return replacement.replace(pattern, (g0, g1, g2) => { - if (typeof g1 !== 'undefined') { - const matchIndex = Number.parseInt(g1, 10); - if (matchIndex >= 1 && matchIndex <= match.length) { - return match[matchIndex]; - } - } else if (typeof g2 !== 'undefined') { - const {groups} = match; - if (typeof groups === 'object' && groups !== null && Object.prototype.hasOwnProperty.call(groups, g2)) { - return groups[g2]; - } - } else { - let {index} = match; - if (typeof index !== 'number') { index = 0; } - switch (g0) { - case '$': return '$'; - case '&': return match[0]; - case '`': return replacement.substring(0, index); - case '\'': return replacement.substring(index + g0.length); - } +/** + * Applies the replacement string for a given regular expression match. + * @param {string} replacement The replacement string that follows the format of the standard + * JavaScript regular expression replacement string. + * @param {RegExpMatchArray} match A match object returned from RegExp.match. + * @returns {string} A new string with the pattern replacement applied. + */ +export function applyMatchReplacement(replacement, match) { + const pattern = matchReplacementPattern; + pattern.lastIndex = 0; + return replacement.replace(pattern, (g0, g1, g2) => { + if (typeof g1 !== 'undefined') { + const matchIndex = Number.parseInt(g1, 10); + if (matchIndex >= 1 && matchIndex <= match.length) { + return match[matchIndex]; } - return g0; - }); - } + } else if (typeof g2 !== 'undefined') { + const {groups} = match; + if (typeof groups === 'object' && groups !== null && Object.prototype.hasOwnProperty.call(groups, g2)) { + return groups[g2]; + } + } else { + let {index} = match; + if (typeof index !== 'number') { index = 0; } + switch (g0) { + case '$': return '$'; + case '&': return match[0]; + case '`': return replacement.substring(0, index); + case '\'': return replacement.substring(index + g0.length); + } + } + return g0; + }); } |