in resources/web/lib/prettify/prettify.js [332:563]
function combinePrefixPatterns(regexs) {
var capturedGroupIndex = 0;
var needToFoldCase = false;
var ignoreCase = false;
for (var i = 0, n = regexs.length; i < n; ++i) {
var regex = regexs[i];
if (regex.ignoreCase) {
ignoreCase = true;
} else if (/[a-z]/i.test(regex.source.replace(
/\\u[0-9a-f]{4}|\\x[0-9a-f]{2}|\\[^ux]/gi, ''))) {
needToFoldCase = true;
ignoreCase = false;
break;
}
}
var escapeCharToCodeUnit = {
'b': 8,
't': 9,
'n': 0xa,
'v': 0xb,
'f': 0xc,
'r': 0xd
};
function decodeEscape(charsetPart) {
var cc0 = charsetPart.charCodeAt(0);
if (cc0 !== 92 /* \\ */) {
return cc0;
}
var c1 = charsetPart.charAt(1);
cc0 = escapeCharToCodeUnit[c1];
if (cc0) {
return cc0;
} else if ('0' <= c1 && c1 <= '7') {
return parseInt(charsetPart.substring(1), 8);
} else if (c1 === 'u' || c1 === 'x') {
return parseInt(charsetPart.substring(2), 16);
} else {
return charsetPart.charCodeAt(1);
}
}
function encodeEscape(charCode) {
if (charCode < 0x20) {
return (charCode < 0x10 ? '\\x0' : '\\x') + charCode.toString(16);
}
var ch = String.fromCharCode(charCode);
return (ch === '\\' || ch === '-' || ch === ']' || ch === '^')
? "\\" + ch : ch;
}
function caseFoldCharset(charSet) {
var charsetParts = charSet.substring(1, charSet.length - 1).match(
new RegExp(
'\\\\u[0-9A-Fa-f]{4}'
+ '|\\\\x[0-9A-Fa-f]{2}'
+ '|\\\\[0-3][0-7]{0,2}'
+ '|\\\\[0-7]{1,2}'
+ '|\\\\[\\s\\S]'
+ '|-'
+ '|[^-\\\\]',
'g'));
var ranges = [];
var inverse = charsetParts[0] === '^';
var out = ['['];
if (inverse) { out.push('^'); }
for (var i = inverse ? 1 : 0, n = charsetParts.length; i < n; ++i) {
var p = charsetParts[i];
if (/\\[bdsw]/i.test(p)) { // Don't muck with named groups.
out.push(p);
} else {
var start = decodeEscape(p);
var end;
if (i + 2 < n && '-' === charsetParts[i + 1]) {
end = decodeEscape(charsetParts[i + 2]);
i += 2;
} else {
end = start;
}
ranges.push([start, end]);
// If the range might intersect letters, then expand it.
// This case handling is too simplistic.
// It does not deal with non-latin case folding.
// It works for latin source code identifiers though.
if (!(end < 65 || start > 122)) {
if (!(end < 65 || start > 90)) {
ranges.push([Math.max(65, start) | 32, Math.min(end, 90) | 32]);
}
if (!(end < 97 || start > 122)) {
ranges.push([Math.max(97, start) & ~32, Math.min(end, 122) & ~32]);
}
}
}
}
// [[1, 10], [3, 4], [8, 12], [14, 14], [16, 16], [17, 17]]
// -> [[1, 12], [14, 14], [16, 17]]
ranges.sort(function (a, b) { return (a[0] - b[0]) || (b[1] - a[1]); });
var consolidatedRanges = [];
var lastRange = [];
for (var i = 0; i < ranges.length; ++i) {
var range = ranges[i];
if (range[0] <= lastRange[1] + 1) {
lastRange[1] = Math.max(lastRange[1], range[1]);
} else {
consolidatedRanges.push(lastRange = range);
}
}
for (var i = 0; i < consolidatedRanges.length; ++i) {
var range = consolidatedRanges[i];
out.push(encodeEscape(range[0]));
if (range[1] > range[0]) {
if (range[1] + 1 > range[0]) { out.push('-'); }
out.push(encodeEscape(range[1]));
}
}
out.push(']');
return out.join('');
}
function allowAnywhereFoldCaseAndRenumberGroups(regex) {
// Split into character sets, escape sequences, punctuation strings
// like ('(', '(?:', ')', '^'), and runs of characters that do not
// include any of the above.
var parts = regex.source.match(
new RegExp(
'(?:'
+ '\\[(?:[^\\x5C\\x5D]|\\\\[\\s\\S])*\\]' // a character set
+ '|\\\\u[A-Fa-f0-9]{4}' // a unicode escape
+ '|\\\\x[A-Fa-f0-9]{2}' // a hex escape
+ '|\\\\[0-9]+' // a back-reference or octal escape
+ '|\\\\[^ux0-9]' // other escape sequence
+ '|\\(\\?[:!=]' // start of a non-capturing group
+ '|[\\(\\)\\^]' // start/end of a group, or line start
+ '|[^\\x5B\\x5C\\(\\)\\^]+' // run of other characters
+ ')',
'g'));
var n = parts.length;
// Maps captured group numbers to the number they will occupy in
// the output or to -1 if that has not been determined, or to
// undefined if they need not be capturing in the output.
var capturedGroups = [];
// Walk over and identify back references to build the capturedGroups
// mapping.
for (var i = 0, groupIndex = 0; i < n; ++i) {
var p = parts[i];
if (p === '(') {
// groups are 1-indexed, so max group index is count of '('
++groupIndex;
} else if ('\\' === p.charAt(0)) {
var decimalValue = +p.substring(1);
if (decimalValue) {
if (decimalValue <= groupIndex) {
capturedGroups[decimalValue] = -1;
} else {
// Replace with an unambiguous escape sequence so that
// an octal escape sequence does not turn into a backreference
// to a capturing group from an earlier regex.
parts[i] = encodeEscape(decimalValue);
}
}
}
}
// Renumber groups and reduce capturing groups to non-capturing groups
// where possible.
for (var i = 1; i < capturedGroups.length; ++i) {
if (-1 === capturedGroups[i]) {
capturedGroups[i] = ++capturedGroupIndex;
}
}
for (var i = 0, groupIndex = 0; i < n; ++i) {
var p = parts[i];
if (p === '(') {
++groupIndex;
if (!capturedGroups[groupIndex]) {
parts[i] = '(?:';
}
} else if ('\\' === p.charAt(0)) {
var decimalValue = +p.substring(1);
if (decimalValue && decimalValue <= groupIndex) {
parts[i] = '\\' + capturedGroups[decimalValue];
}
}
}
// Remove any prefix anchors so that the output will match anywhere.
// ^^ really does mean an anchored match though.
for (var i = 0; i < n; ++i) {
if ('^' === parts[i] && '^' !== parts[i + 1]) { parts[i] = ''; }
}
// Expand letters to groups to handle mixing of case-sensitive and
// case-insensitive patterns if necessary.
if (regex.ignoreCase && needToFoldCase) {
for (var i = 0; i < n; ++i) {
var p = parts[i];
var ch0 = p.charAt(0);
if (p.length >= 2 && ch0 === '[') {
parts[i] = caseFoldCharset(p);
} else if (ch0 !== '\\') {
// TODO: handle letters in numeric escapes.
parts[i] = p.replace(
/[a-zA-Z]/g,
function (ch) {
var cc = ch.charCodeAt(0);
return '[' + String.fromCharCode(cc & ~32, cc | 32) + ']';
});
}
}
}
return parts.join('');
}
var rewritten = [];
for (var i = 0, n = regexs.length; i < n; ++i) {
var regex = regexs[i];
if (regex.global || regex.multiline) { throw new Error('' + regex); }
rewritten.push(
'(?:' + allowAnywhereFoldCaseAndRenumberGroups(regex) + ')');
}
return new RegExp(rewritten.join('|'), ignoreCase ? 'gi' : 'g');
}