setup-php/node_modules/regexp-tree/dist/optimizer/transforms/char-case-insensitive-lowercase-transform.js
2019-09-20 21:54:46 +05:30

110 lines
3.1 KiB
JavaScript

/**
* The MIT License (MIT)
* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
*/
'use strict';
var UPPER_A_CP = 'A'.codePointAt(0);
var UPPER_Z_CP = 'Z'.codePointAt(0);
/**
* Transforms case-insensitive regexp to lowercase
*
* /AaBbÏ/i -> /aabbï/i
*/
module.exports = {
_AZClassRanges: null,
_hasUFlag: false,
init: function init(ast) {
this._AZClassRanges = new Set();
this._hasUFlag = ast.flags.includes('u');
},
shouldRun: function shouldRun(ast) {
return ast.flags.includes('i');
},
Char: function Char(path) {
var node = path.node,
parent = path.parent;
if (isNaN(node.codePoint)) {
return;
}
// Engine support for case-insensitive matching without the u flag
// for characters above \u1000 does not seem reliable.
if (!this._hasUFlag && node.codePoint >= 0x1000) {
return;
}
if (parent.type === 'ClassRange') {
// The only class ranges we handle must be inside A-Z.
// After the `from` char is processed, the isAZClassRange test
// will be false, so we use a Set to keep track of parents and
// process the `to` char.
if (!this._AZClassRanges.has(parent) && !isAZClassRange(parent)) {
return;
}
this._AZClassRanges.add(parent);
}
var lower = node.symbol.toLowerCase();
if (lower !== node.symbol) {
node.value = displaySymbolAsValue(lower, node);
node.symbol = lower;
node.codePoint = lower.codePointAt(0);
}
}
};
function isAZClassRange(classRange) {
var from = classRange.from,
to = classRange.to;
// A-Z
return from.codePoint >= UPPER_A_CP && from.codePoint <= UPPER_Z_CP && to.codePoint >= UPPER_A_CP && to.codePoint <= UPPER_Z_CP;
}
function displaySymbolAsValue(symbol, node) {
var codePoint = symbol.codePointAt(0);
if (node.kind === 'decimal') {
return '\\' + codePoint;
}
if (node.kind === 'oct') {
return '\\0' + codePoint.toString(8);
}
if (node.kind === 'hex') {
return '\\x' + codePoint.toString(16);
}
if (node.kind === 'unicode') {
if (node.isSurrogatePair) {
var _getSurrogatePairFrom = getSurrogatePairFromCodePoint(codePoint),
lead = _getSurrogatePairFrom.lead,
trail = _getSurrogatePairFrom.trail;
return '\\u' + '0'.repeat(4 - lead.length) + lead + '\\u' + '0'.repeat(4 - trail.length) + trail;
} else if (node.value.includes('{')) {
return '\\u{' + codePoint.toString(16) + '}';
} else {
var code = codePoint.toString(16);
return '\\u' + '0'.repeat(4 - code.length) + code;
}
}
// simple
return symbol;
}
/**
* Converts a code point to a surrogate pair.
* Conversion algorithm is taken from The Unicode Standard 3.0 Section 3.7
* (https://www.unicode.org/versions/Unicode3.0.0/ch03.pdf)
* @param {number} codePoint - Between 0x10000 and 0x10ffff
* @returns {{lead: string, trail: string}}
*/
function getSurrogatePairFromCodePoint(codePoint) {
var lead = Math.floor((codePoint - 0x10000) / 0x400) + 0xd800;
var trail = (codePoint - 0x10000) % 0x400 + 0xdc00;
return {
lead: lead.toString(16),
trail: trail.toString(16)
};
}