initial commit

vendor/yomitan/js/general/regex-util.js

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2023-2025  Yomitan Authors
+ * Copyright (C) 2021-2022  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/** @type {RegExp} @readonly */
+const matchReplacementPattern = /\$(?:\$|&|`|'|(\d\d?)|<([^>]*)>)/g;
+
+/**
+ * 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 {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 function applyTextReplacement(text, 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);
+
+        text = `${text.substring(0, index)}${actualReplacement}${text.substring(index + matchText.length)}`;
+        pattern.lastIndex += delta;
+    }
+    return text;
+}
+
+/**
+ * Applies the replacement string for a given regular expression match.
+ * @param {string} replacement The replacement string that follows the format of the standard
+ *   JavaScript regular expression replacement string.
+ * @param {RegExpMatchArray} match A match object returned from RegExp.match.
+ * @returns {string} A new string with the pattern replacement applied.
+ */
+export function applyMatchReplacement(replacement, match) {
+    const pattern = matchReplacementPattern;
+    pattern.lastIndex = 0;
+    /**
+     * @param {string} g0
+     * @param {string} g1
+     * @param {string} g2
+     * @returns {string}
+     */
+    const replacer = (g0, g1, g2) => {
+        if (typeof g1 !== 'undefined') {
+            const matchIndex = Number.parseInt(g1, 10);
+            if (matchIndex >= 1 && matchIndex <= match.length) {
+                return match[matchIndex];
+            }
+        } else if (typeof g2 !== 'undefined') {
+            const {groups} = match;
+            if (typeof groups === 'object' && groups !== null && Object.prototype.hasOwnProperty.call(groups, g2)) {
+                return groups[g2];
+            }
+        } else {
+            let {index} = match;
+            if (typeof index !== 'number') { index = 0; }
+            switch (g0) {
+                case '$': return '$';
+                case '&': return match[0];
+                case '`': return replacement.substring(0, index);
+                case '\'': return replacement.substring(index + g0.length);
+            }
+        }
+        return g0;
+    };
+    return replacement.replace(pattern, replacer);
+}