346 lines
9.9 KiB
JavaScript
346 lines
9.9 KiB
JavaScript
'use strict';
|
||
|
||
const generate = require('regjsgen').generate;
|
||
const parse = require('regjsparser').parse;
|
||
const regenerate = require('regenerate');
|
||
const unicodeMatchProperty = require('unicode-match-property-ecmascript');
|
||
const unicodeMatchPropertyValue = require('unicode-match-property-value-ecmascript');
|
||
const iuMappings = require('./data/iu-mappings.js');
|
||
const ESCAPE_SETS = require('./data/character-class-escape-sets.js');
|
||
|
||
// Prepare a Regenerate set containing all code points, used for negative
|
||
// character classes (if any).
|
||
const UNICODE_SET = regenerate().addRange(0x0, 0x10FFFF);
|
||
// Without the `u` flag, the range stops at 0xFFFF.
|
||
// https://mths.be/es6#sec-pattern-semantics
|
||
const BMP_SET = regenerate().addRange(0x0, 0xFFFF);
|
||
|
||
// Prepare a Regenerate set containing all code points that are supposed to be
|
||
// matched by `/./u`. https://mths.be/es6#sec-atom
|
||
const DOT_SET_UNICODE = UNICODE_SET.clone() // all Unicode code points
|
||
.remove(
|
||
// minus `LineTerminator`s (https://mths.be/es6#sec-line-terminators):
|
||
0x000A, // Line Feed <LF>
|
||
0x000D, // Carriage Return <CR>
|
||
0x2028, // Line Separator <LS>
|
||
0x2029 // Paragraph Separator <PS>
|
||
);
|
||
|
||
const getCharacterClassEscapeSet = (character, unicode, ignoreCase) => {
|
||
if (unicode) {
|
||
if (ignoreCase) {
|
||
return ESCAPE_SETS.UNICODE_IGNORE_CASE.get(character);
|
||
}
|
||
return ESCAPE_SETS.UNICODE.get(character);
|
||
}
|
||
return ESCAPE_SETS.REGULAR.get(character);
|
||
};
|
||
|
||
const getUnicodeDotSet = (dotAll) => {
|
||
return dotAll ? UNICODE_SET : DOT_SET_UNICODE;
|
||
};
|
||
|
||
const getUnicodePropertyValueSet = (property, value) => {
|
||
const path = value ?
|
||
`${ property }/${ value }` :
|
||
`Binary_Property/${ property }`;
|
||
try {
|
||
return require(`regenerate-unicode-properties/${ path }.js`);
|
||
} catch (exception) {
|
||
throw new Error(
|
||
`Failed to recognize value \`${ value }\` for property ` +
|
||
`\`${ property }\`.`
|
||
);
|
||
}
|
||
};
|
||
|
||
const handleLoneUnicodePropertyNameOrValue = (value) => {
|
||
// It could be a `General_Category` value or a binary property.
|
||
// Note: `unicodeMatchPropertyValue` throws on invalid values.
|
||
try {
|
||
const property = 'General_Category';
|
||
const category = unicodeMatchPropertyValue(property, value);
|
||
return getUnicodePropertyValueSet(property, category);
|
||
} catch (exception) {}
|
||
// It’s not a `General_Category` value, so check if it’s a binary
|
||
// property. Note: `unicodeMatchProperty` throws on invalid properties.
|
||
const property = unicodeMatchProperty(value);
|
||
return getUnicodePropertyValueSet(property);
|
||
};
|
||
|
||
const getUnicodePropertyEscapeSet = (value, isNegative) => {
|
||
const parts = value.split('=');
|
||
const firstPart = parts[0];
|
||
let set;
|
||
if (parts.length == 1) {
|
||
set = handleLoneUnicodePropertyNameOrValue(firstPart);
|
||
} else {
|
||
// The pattern consists of two parts, i.e. `Property=Value`.
|
||
const property = unicodeMatchProperty(firstPart);
|
||
const value = unicodeMatchPropertyValue(property, parts[1]);
|
||
set = getUnicodePropertyValueSet(property, value);
|
||
}
|
||
if (isNegative) {
|
||
return UNICODE_SET.clone().remove(set);
|
||
}
|
||
return set.clone();
|
||
};
|
||
|
||
// Given a range of code points, add any case-folded code points in that range
|
||
// to a set.
|
||
regenerate.prototype.iuAddRange = function(min, max) {
|
||
const $this = this;
|
||
do {
|
||
const folded = caseFold(min);
|
||
if (folded) {
|
||
$this.add(folded);
|
||
}
|
||
} while (++min <= max);
|
||
return $this;
|
||
};
|
||
|
||
const update = (item, pattern) => {
|
||
let tree = parse(pattern, config.useUnicodeFlag ? 'u' : '');
|
||
switch (tree.type) {
|
||
case 'characterClass':
|
||
case 'group':
|
||
case 'value':
|
||
// No wrapping needed.
|
||
break;
|
||
default:
|
||
// Wrap the pattern in a non-capturing group.
|
||
tree = wrap(tree, pattern);
|
||
}
|
||
Object.assign(item, tree);
|
||
};
|
||
|
||
const wrap = (tree, pattern) => {
|
||
// Wrap the pattern in a non-capturing group.
|
||
return {
|
||
'type': 'group',
|
||
'behavior': 'ignore',
|
||
'body': [tree],
|
||
'raw': `(?:${ pattern })`
|
||
};
|
||
};
|
||
|
||
const caseFold = (codePoint) => {
|
||
return iuMappings.get(codePoint) || false;
|
||
};
|
||
|
||
const processCharacterClass = (characterClassItem, regenerateOptions) => {
|
||
const set = regenerate();
|
||
for (const item of characterClassItem.body) {
|
||
switch (item.type) {
|
||
case 'value':
|
||
set.add(item.codePoint);
|
||
if (config.ignoreCase && config.unicode && !config.useUnicodeFlag) {
|
||
const folded = caseFold(item.codePoint);
|
||
if (folded) {
|
||
set.add(folded);
|
||
}
|
||
}
|
||
break;
|
||
case 'characterClassRange':
|
||
const min = item.min.codePoint;
|
||
const max = item.max.codePoint;
|
||
set.addRange(min, max);
|
||
if (config.ignoreCase && config.unicode && !config.useUnicodeFlag) {
|
||
set.iuAddRange(min, max);
|
||
}
|
||
break;
|
||
case 'characterClassEscape':
|
||
set.add(getCharacterClassEscapeSet(
|
||
item.value,
|
||
config.unicode,
|
||
config.ignoreCase
|
||
));
|
||
break;
|
||
case 'unicodePropertyEscape':
|
||
set.add(getUnicodePropertyEscapeSet(item.value, item.negative));
|
||
break;
|
||
// The `default` clause is only here as a safeguard; it should never be
|
||
// reached. Code coverage tools should ignore it.
|
||
/* istanbul ignore next */
|
||
default:
|
||
throw new Error(`Unknown term type: ${ item.type }`);
|
||
}
|
||
}
|
||
if (characterClassItem.negative) {
|
||
update(characterClassItem, `(?!${set.toString(regenerateOptions)})[\\s\\S]`)
|
||
} else {
|
||
update(characterClassItem, set.toString(regenerateOptions));
|
||
}
|
||
return characterClassItem;
|
||
};
|
||
|
||
const updateNamedReference = (item, index) => {
|
||
delete item.name;
|
||
item.matchIndex = index;
|
||
};
|
||
|
||
const assertNoUnmatchedReferences = (groups) => {
|
||
const unmatchedReferencesNames = Object.keys(groups.unmatchedReferences);
|
||
if (unmatchedReferencesNames.length > 0) {
|
||
throw new Error(`Unknown group names: ${unmatchedReferencesNames}`);
|
||
}
|
||
};
|
||
|
||
const processTerm = (item, regenerateOptions, groups) => {
|
||
switch (item.type) {
|
||
case 'dot':
|
||
if (config.useDotAllFlag) {
|
||
break;
|
||
} else if (config.unicode) {
|
||
update(
|
||
item,
|
||
getUnicodeDotSet(config.dotAll).toString(regenerateOptions)
|
||
);
|
||
} else if (config.dotAll) {
|
||
// TODO: consider changing this at the regenerate level.
|
||
update(item, '[\\s\\S]');
|
||
}
|
||
break;
|
||
case 'characterClass':
|
||
item = processCharacterClass(item, regenerateOptions);
|
||
break;
|
||
case 'unicodePropertyEscape':
|
||
if (config.unicodePropertyEscape) {
|
||
update(
|
||
item,
|
||
getUnicodePropertyEscapeSet(item.value, item.negative)
|
||
.toString(regenerateOptions)
|
||
);
|
||
}
|
||
break;
|
||
case 'characterClassEscape':
|
||
update(
|
||
item,
|
||
getCharacterClassEscapeSet(
|
||
item.value,
|
||
config.unicode,
|
||
config.ignoreCase
|
||
).toString(regenerateOptions)
|
||
);
|
||
break;
|
||
case 'group':
|
||
if (item.behavior == 'normal') {
|
||
groups.lastIndex++;
|
||
}
|
||
if (item.name && config.namedGroup) {
|
||
const name = item.name.value;
|
||
|
||
if (groups.names[name]) {
|
||
throw new Error(
|
||
`Multiple groups with the same name (${ name }) are not allowed.`
|
||
);
|
||
}
|
||
|
||
const index = groups.lastIndex;
|
||
delete item.name;
|
||
|
||
groups.names[name] = index;
|
||
if (groups.onNamedGroup) {
|
||
groups.onNamedGroup.call(null, name, index);
|
||
}
|
||
|
||
if (groups.unmatchedReferences[name]) {
|
||
groups.unmatchedReferences[name].forEach(reference => {
|
||
updateNamedReference(reference, index);
|
||
});
|
||
delete groups.unmatchedReferences[name];
|
||
}
|
||
}
|
||
/* falls through */
|
||
case 'alternative':
|
||
case 'disjunction':
|
||
case 'quantifier':
|
||
item.body = item.body.map(term => {
|
||
return processTerm(term, regenerateOptions, groups);
|
||
});
|
||
break;
|
||
case 'value':
|
||
const codePoint = item.codePoint;
|
||
const set = regenerate(codePoint);
|
||
if (config.ignoreCase && config.unicode && !config.useUnicodeFlag) {
|
||
const folded = caseFold(codePoint);
|
||
if (folded) {
|
||
set.add(folded);
|
||
}
|
||
}
|
||
update(item, set.toString(regenerateOptions));
|
||
break;
|
||
case 'reference':
|
||
if (item.name) {
|
||
const name = item.name.value;
|
||
const index = groups.names[name];
|
||
if (index) {
|
||
updateNamedReference(item, index);
|
||
break;
|
||
}
|
||
|
||
if (!groups.unmatchedReferences[name]) {
|
||
groups.unmatchedReferences[name] = [];
|
||
}
|
||
// Keep track of references used before the corresponding group.
|
||
groups.unmatchedReferences[name].push(item);
|
||
}
|
||
break;
|
||
case 'anchor':
|
||
case 'empty':
|
||
case 'group':
|
||
// Nothing to do here.
|
||
break;
|
||
// The `default` clause is only here as a safeguard; it should never be
|
||
// reached. Code coverage tools should ignore it.
|
||
/* istanbul ignore next */
|
||
default:
|
||
throw new Error(`Unknown term type: ${ item.type }`);
|
||
}
|
||
return item;
|
||
};
|
||
|
||
const config = {
|
||
'ignoreCase': false,
|
||
'unicode': false,
|
||
'dotAll': false,
|
||
'useDotAllFlag': false,
|
||
'useUnicodeFlag': false,
|
||
'unicodePropertyEscape': false,
|
||
'namedGroup': false
|
||
};
|
||
const rewritePattern = (pattern, flags, options) => {
|
||
config.unicode = flags && flags.includes('u');
|
||
const regjsparserFeatures = {
|
||
'unicodePropertyEscape': config.unicode,
|
||
'namedGroups': true,
|
||
'lookbehind': options && options.lookbehind
|
||
};
|
||
config.ignoreCase = flags && flags.includes('i');
|
||
const supportDotAllFlag = options && options.dotAllFlag;
|
||
config.dotAll = supportDotAllFlag && flags && flags.includes('s');
|
||
config.namedGroup = options && options.namedGroup;
|
||
config.useDotAllFlag = options && options.useDotAllFlag;
|
||
config.useUnicodeFlag = options && options.useUnicodeFlag;
|
||
config.unicodePropertyEscape = options && options.unicodePropertyEscape;
|
||
if (supportDotAllFlag && config.useDotAllFlag) {
|
||
throw new Error('`useDotAllFlag` and `dotAllFlag` cannot both be true!');
|
||
}
|
||
const regenerateOptions = {
|
||
'hasUnicodeFlag': config.useUnicodeFlag,
|
||
'bmpOnly': !config.unicode
|
||
};
|
||
const groups = {
|
||
'onNamedGroup': options && options.onNamedGroup,
|
||
'lastIndex': 0,
|
||
'names': Object.create(null), // { [name]: index }
|
||
'unmatchedReferences': Object.create(null) // { [name]: Array<reference> }
|
||
};
|
||
const tree = parse(pattern, flags, regjsparserFeatures);
|
||
// Note: `processTerm` mutates `tree` and `groups`.
|
||
processTerm(tree, regenerateOptions, groups);
|
||
assertNoUnmatchedReferences(groups);
|
||
return generate(tree);
|
||
};
|
||
|
||
module.exports = rewritePattern;
|