/*!
* XRegExp.build 4.0.0
* <xregexp.com>
* Steven Levithan (c) 2012-2017 MIT License
*/
export default (XRegExp) => {
const REGEX_DATA = 'xregexp';
const subParts = /(\()(?!\?)|\\([1-9]\d*)|\\[\s\S]|\[(?:[^\\\]]|\\[\s\S])*\]/g;
const parts = XRegExp.union([/\({{([\w$]+)}}\)|{{([\w$]+)}}/, subParts], 'g', {
conjunction: 'or'
});
/**
* Strips a leading `^` and trailing unescaped `$`, if both are present.
*
* @private
* @param {String} pattern Pattern to process.
* @returns {String} Pattern with edge anchors removed.
*/
function deanchor(pattern) {
// Allow any number of empty noncapturing groups before/after anchors, because regexes
// built/generated by XRegExp sometimes include them
const leadingAnchor = /^(?:\(\?:\))*\^/;
const trailingAnchor = /\$(?:\(\?:\))*$/;
if (
leadingAnchor.test(pattern) &&
trailingAnchor.test(pattern) &&
// Ensure that the trailing `$` isn't escaped
trailingAnchor.test(pattern.replace(/\\[\s\S]/g, ''))
) {
return pattern.replace(leadingAnchor, '').replace(trailingAnchor, '');
}
return pattern;
}
/**
* Converts the provided value to an XRegExp. Native RegExp flags are not preserved.
*
* @private
* @param {String|RegExp} value Value to convert.
* @param {Boolean} [addFlagX] Whether to apply the `x` flag in cases when `value` is not
* already a regex generated by XRegExp
* @returns {RegExp} XRegExp object with XRegExp syntax applied.
*/
function asXRegExp(value, addFlagX) {
const flags = addFlagX ? 'x' : '';
return XRegExp.isRegExp(value) ?
(value[REGEX_DATA] && value[REGEX_DATA].captureNames ?
// Don't recompile, to preserve capture names
value :
// Recompile as XRegExp
XRegExp(value.source, flags)
) :
// Compile string as XRegExp
XRegExp(value, flags);
}
function interpolate(substitution) {
return substitution instanceof RegExp ? substitution : XRegExp.escape(substitution);
}
function reduceToSubpatternsObject(subpatterns, interpolated, subpatternIndex) {
subpatterns[`subpattern${subpatternIndex}`] = interpolated;
return subpatterns;
}
function embedSubpatternAfter(raw, subpatternIndex, rawLiterals) {
const hasSubpattern = subpatternIndex < rawLiterals.length - 1;
return raw + (hasSubpattern ? `{{subpattern${subpatternIndex}}}` : '');
}
/**
* Provides tagged template literals that create regexes with XRegExp syntax and flags. The
* provided pattern is handled as a raw string, so backslashes don't need to be escaped.
*
* Interpolation of strings and regexes shares the features of `XRegExp.build`. Interpolated
* patterns are treated as atomic units when quantified, interpolated strings have their special
* characters escaped, a leading `^` and trailing unescaped `$` are stripped from interpolated
* regexes if both are present, and any backreferences within an interpolated regex are
* rewritten to work within the overall pattern.
*
* @memberOf XRegExp
* @param {String} [flags] Any combination of XRegExp flags.
* @returns {Function} Handler for template literals that construct regexes with XRegExp syntax.
* @example
*
* const h12 = /1[0-2]|0?[1-9]/;
* const h24 = /2[0-3]|[01][0-9]/;
* const hours = XRegExp.tag('x')`${h12} : | ${h24}`;
* const minutes = /^[0-5][0-9]$/;
* // Note that explicitly naming the 'minutes' group is required for named backreferences
* const time = XRegExp.tag('x')`^ ${hours} (?<minutes>${minutes}) $`;
* time.test('10:59'); // -> true
* XRegExp.exec('10:59', time).minutes; // -> '59'
*/
XRegExp.tag = (flags) => (literals, ...substitutions) => {
const subpatterns = substitutions.map(interpolate).reduce(reduceToSubpatternsObject, {});
const pattern = literals.raw.map(embedSubpatternAfter).join('');
return XRegExp.build(pattern, subpatterns, flags);
};
/**
* Builds regexes using named subpatterns, for readability and pattern reuse. Backreferences in
* the outer pattern and provided subpatterns are automatically renumbered to work correctly.
* Native flags used by provided subpatterns are ignored in favor of the `flags` argument.
*
* @memberOf XRegExp
* @param {String} pattern XRegExp pattern using `{{name}}` for embedded subpatterns. Allows
* `({{name}})` as shorthand for `(?<name>{{name}})`. Patterns cannot be embedded within
* character classes.
* @param {Object} subs Lookup object for named subpatterns. Values can be strings or regexes. A
* leading `^` and trailing unescaped `$` are stripped from subpatterns, if both are present.
* @param {String} [flags] Any combination of XRegExp flags.
* @returns {RegExp} Regex with interpolated subpatterns.
* @example
*
* const time = XRegExp.build('(?x)^ {{hours}} ({{minutes}}) $', {
* hours: XRegExp.build('{{h12}} : | {{h24}}', {
* h12: /1[0-2]|0?[1-9]/,
* h24: /2[0-3]|[01][0-9]/
* }, 'x'),
* minutes: /^[0-5][0-9]$/
* });
* time.test('10:59'); // -> true
* XRegExp.exec('10:59', time).minutes; // -> '59'
*/
XRegExp.build = (pattern, subs, flags) => {
flags = flags || '';
// Used with `asXRegExp` calls for `pattern` and subpatterns in `subs`, to work around how
// some browsers convert `RegExp('\n')` to a regex that contains the literal characters `\`
// and `n`. See more details at <https://github.com/slevithan/xregexp/pull/163>.
const addFlagX = flags.includes('x');
const inlineFlags = /^\(\?([\w$]+)\)/.exec(pattern);
// Add flags within a leading mode modifier to the overall pattern's flags
if (inlineFlags) {
flags = XRegExp._clipDuplicates(flags + inlineFlags[1]);
}
const data = {};
for (const p in subs) {
if (subs.hasOwnProperty(p)) {
// Passing to XRegExp enables extended syntax and ensures independent validity,
// lest an unescaped `(`, `)`, `[`, or trailing `\` breaks the `(?:)` wrapper. For
// subpatterns provided as native regexes, it dies on octals and adds the property
// used to hold extended regex instance data, for simplicity.
const sub = asXRegExp(subs[p], addFlagX);
data[p] = {
// Deanchoring allows embedding independently useful anchored regexes. If you
// really need to keep your anchors, double them (i.e., `^^...$$`).
pattern: deanchor(sub.source),
names: sub[REGEX_DATA].captureNames || []
};
}
}
// Passing to XRegExp dies on octals and ensures the outer pattern is independently valid;
// helps keep this simple. Named captures will be put back.
const patternAsRegex = asXRegExp(pattern, addFlagX);
// 'Caps' is short for 'captures'
let numCaps = 0;
let numPriorCaps;
let numOuterCaps = 0;
const outerCapsMap = [0];
const outerCapNames = patternAsRegex[REGEX_DATA].captureNames || [];
const output = patternAsRegex.source.replace(parts, ($0, $1, $2, $3, $4) => {
const subName = $1 || $2;
let capName;
let intro;
let localCapIndex;
// Named subpattern
if (subName) {
if (!data.hasOwnProperty(subName)) {
throw new ReferenceError(`Undefined property ${$0}`);
}
// Named subpattern was wrapped in a capturing group
if ($1) {
capName = outerCapNames[numOuterCaps];
outerCapsMap[++numOuterCaps] = ++numCaps;
// If it's a named group, preserve the name. Otherwise, use the subpattern name
// as the capture name
intro = `(?<${capName || subName}>`;
} else {
intro = '(?:';
}
numPriorCaps = numCaps;
const rewrittenSubpattern = data[subName].pattern.replace(subParts, (match, paren, backref) => {
// Capturing group
if (paren) {
capName = data[subName].names[numCaps - numPriorCaps];
++numCaps;
// If the current capture has a name, preserve the name
if (capName) {
return `(?<${capName}>`;
}
// Backreference
} else if (backref) {
localCapIndex = +backref - 1;
// Rewrite the backreference
return data[subName].names[localCapIndex] ?
// Need to preserve the backreference name in case using flag `n`
`\\k<${data[subName].names[localCapIndex]}>` :
`\\${+backref + numPriorCaps}`;
}
return match;
});
return `${intro}${rewrittenSubpattern})`;
}
// Capturing group
if ($3) {
capName = outerCapNames[numOuterCaps];
outerCapsMap[++numOuterCaps] = ++numCaps;
// If the current capture has a name, preserve the name
if (capName) {
return `(?<${capName}>`;
}
// Backreference
} else if ($4) {
localCapIndex = +$4 - 1;
// Rewrite the backreference
return outerCapNames[localCapIndex] ?
// Need to preserve the backreference name in case using flag `n`
`\\k<${outerCapNames[localCapIndex]}>` :
`\\${outerCapsMap[+$4]}`;
}
return $0;
});
return XRegExp(output, flags);
};
};