@awayfl/avm2/dist/lib/nat/XRegLookup.js

Virtual machine for executing AS3 code

/* eslint-disable no-cond-assign */
import XRegExpOrig from 'xregexp/lib';
(function (XRegExp) {
    function preparePattern(pattern, flags) {
        var lbOpen, lbEndPos, lbInner;
        flags = flags || '';
        // Extract flags from a leading mode modifier, if present
        pattern = pattern.replace(/^\(\?([\w$]+)\)/, function ($0, $1) {
            flags += $1;
            return '';
        });
        if (lbOpen = /^\(\?<([=!])/.exec(pattern)) {
            // Extract the lookbehind pattern. Allows nested groups, escaped parens, and unescaped parens within classes
            lbEndPos = XRegExp.matchRecursive(pattern, /\((?:[^()[\\]|\\.|\[(?:[^\\\]]|\\.)*])*/.source, '\\)', 's', {
                valueNames: [null, null, null, 'right'],
                escapeChar: '\\'
            })[0].end;
            lbInner = pattern.slice('(?<='.length, lbEndPos - 1);
        }
        else {
            throw new Error('lookbehind not at start of pattern');
        }
        return {
            lb: XRegExp('(?:' + lbInner + ')$(?!\\s)', flags.replace(/[gy]/g, '')),
            lbType: lbOpen[1] === '=',
            main: XRegExp(pattern.slice(('(?<=)' + lbInner).length), flags)
        };
    }
    XRegExp.execLb = function (str, pattern, flags) {
        var pos = 0, match, leftContext;
        var rex = preparePattern(pattern, flags);
        while (match = XRegExp.exec(str, rex.main, pos)) {
            leftContext = str.slice(0, match.index);
            if (rex.lbType === rex.lb.test(leftContext)) {
                return match;
            }
            pos = match.index + 1;
        }
        return null;
    };
    XRegExp.testLb = function (str, pattern, flags) {
        return !!XRegExp.execLb(str, pattern, flags);
    };
    XRegExp.searchLb = function (str, pattern, flags) {
        var match = XRegExp.execLb(str, pattern, flags);
        return match ? match.index : -1;
    };
    XRegExp.matchAllLb = function (str, pattern, flags) {
        var matches = [];
        var pos = 0, match, leftContext;
        var rex = preparePattern(pattern, flags);
        while (match = XRegExp.exec(str, rex.main, pos)) {
            leftContext = str.slice(0, match.index);
            if (rex.lbType === rex.lb.test(leftContext)) {
                matches.push(match[0]);
                pos = match.index + (match[0].length || 1);
            }
            else {
                pos = match.index + 1;
            }
        }
        return matches;
    };
    XRegExp.replaceLb = function (str, pattern, replacement, flags) {
        var output = '', pos = 0, lastEnd = 0, match, leftContext;
        var rex = preparePattern(pattern, flags);
        while (match = XRegExp.exec(str, rex.main, pos)) {
            leftContext = str.slice(0, match.index);
            if (rex.lbType === rex.lb.test(leftContext)) {
                // Doesn't work correctly if lookahead in regex looks outside of the match
                output += str.slice(lastEnd, match.index) + XRegExp.replace(match[0], rex.main, replacement);
                lastEnd = match.index + match[0].length;
                if (!rex.main.global) {
                    break;
                }
                pos = match.index + (match[0].length || 1);
            }
            else {
                pos = match.index + 1;
            }
        }
        return output + str.slice(lastEnd);
    };
}(XRegExpOrig));
var XRegExp = XRegExpOrig;
export { XRegExp };