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

211 lines
4.8 KiB
JavaScript

/**
* The MIT License (MIT)
* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
*/
'use strict';
/**
* A regexp-tree plugin to replace standard character classes with
* their meta symbols equivalents.
*/
module.exports = {
_hasIFlag: false,
_hasUFlag: false,
init: function init(ast) {
this._hasIFlag = ast.flags.includes('i');
this._hasUFlag = ast.flags.includes('u');
},
CharacterClass: function CharacterClass(path) {
// [0-9] -> \d
rewriteNumberRanges(path);
// [a-zA-Z_0-9] -> \w
rewriteWordRanges(path, this._hasIFlag, this._hasUFlag);
// [ \t\r\n\f] -> \s
rewriteWhitespaceRanges(path);
}
};
/**
* Rewrites number ranges: [0-9] -> \d
*/
function rewriteNumberRanges(path) {
var node = path.node;
node.expressions.forEach(function (expression, i) {
if (isFullNumberRange(expression)) {
path.getChild(i).replace({
type: 'Char',
value: '\\d',
kind: 'meta'
});
}
});
}
/**
* Rewrites word ranges: [a-zA-Z_0-9] -> \w
* Thus, the ranges may go in any order, and other symbols/ranges
* are kept untouched, e.g. [a-z_\dA-Z$] -> [\w$]
*/
function rewriteWordRanges(path, hasIFlag, hasUFlag) {
var node = path.node;
var numberPath = null;
var lowerCasePath = null;
var upperCasePath = null;
var underscorePath = null;
var u017fPath = null;
var u212aPath = null;
node.expressions.forEach(function (expression, i) {
// \d
if (isMetaChar(expression, '\\d')) {
numberPath = path.getChild(i);
}
// a-z
else if (isLowerCaseRange(expression)) {
lowerCasePath = path.getChild(i);
}
// A-Z
else if (isUpperCaseRange(expression)) {
upperCasePath = path.getChild(i);
}
// _
else if (isUnderscore(expression)) {
underscorePath = path.getChild(i);
} else if (hasIFlag && hasUFlag && isU017fPath(expression)) {
u017fPath = path.getChild(i);
} else if (hasIFlag && hasUFlag && isU212aPath(expression)) {
u212aPath = path.getChild(i);
}
});
// If we found the whole pattern, replace it.
if (numberPath && (lowerCasePath && upperCasePath || hasIFlag && (lowerCasePath || upperCasePath)) && underscorePath && (!hasUFlag || !hasIFlag || u017fPath && u212aPath)) {
// Put \w in place of \d.
numberPath.replace({
type: 'Char',
value: '\\w',
kind: 'meta'
});
// Other paths are removed.
if (lowerCasePath) {
lowerCasePath.remove();
}
if (upperCasePath) {
upperCasePath.remove();
}
underscorePath.remove();
if (u017fPath) {
u017fPath.remove();
}
if (u212aPath) {
u212aPath.remove();
}
}
}
/**
* Rewrites whitespace ranges: [ \t\r\n\f] -> \s.
*/
function rewriteWhitespaceRanges(path) {
var node = path.node;
var spacePath = null;
var tPath = null;
var nPath = null;
var rPath = null;
var fPath = null;
node.expressions.forEach(function (expression, i) {
// Space
if (isChar(expression, ' ')) {
spacePath = path.getChild(i);
}
// \t
else if (isMetaChar(expression, '\\t')) {
tPath = path.getChild(i);
}
// \n
else if (isMetaChar(expression, '\\n')) {
nPath = path.getChild(i);
}
// \r
else if (isMetaChar(expression, '\\r')) {
rPath = path.getChild(i);
}
// \f
else if (isMetaChar(expression, '\\f')) {
fPath = path.getChild(i);
}
});
// If we found the whole pattern, replace it.
// Make \f optional.
if (spacePath && tPath && nPath && rPath) {
// Put \s in place of \n.
nPath.node.value = '\\s';
// Other paths are removed.
spacePath.remove();
tPath.remove();
rPath.remove();
if (fPath) {
fPath.remove();
}
}
}
function isFullNumberRange(node) {
return node.type === 'ClassRange' && node.from.value === '0' && node.to.value === '9';
}
function isChar(node, value) {
var kind = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 'simple';
return node.type === 'Char' && node.value === value && node.kind === kind;
}
function isMetaChar(node, value) {
return isChar(node, value, 'meta');
}
function isLowerCaseRange(node) {
return node.type === 'ClassRange' && node.from.value === 'a' && node.to.value === 'z';
}
function isUpperCaseRange(node) {
return node.type === 'ClassRange' && node.from.value === 'A' && node.to.value === 'Z';
}
function isUnderscore(node) {
return node.type === 'Char' && node.value === '_' && node.kind === 'simple';
}
function isU017fPath(node) {
return node.type === 'Char' && node.kind === 'unicode' && node.codePoint === 0x017f;
}
function isU212aPath(node) {
return node.type === 'Char' && node.kind === 'unicode' && node.codePoint === 0x212a;
}