|
|
- /*!
- * to-regex-range <https://github.com/jonschlinkert/to-regex-range>
- *
- * Copyright (c) 2015, 2017, Jon Schlinkert.
- * Released under the MIT License.
- */
-
- 'use strict';
-
- var repeat = require('repeat-string');
- var isNumber = require('is-number');
- var cache = {};
-
- function toRegexRange(min, max, options) {
- if (isNumber(min) === false) {
- throw new RangeError('toRegexRange: first argument is invalid.');
- }
-
- if (typeof max === 'undefined' || min === max) {
- return String(min);
- }
-
- if (isNumber(max) === false) {
- throw new RangeError('toRegexRange: second argument is invalid.');
- }
-
- options = options || {};
- var relax = String(options.relaxZeros);
- var shorthand = String(options.shorthand);
- var capture = String(options.capture);
- var key = min + ':' + max + '=' + relax + shorthand + capture;
- if (cache.hasOwnProperty(key)) {
- return cache[key].result;
- }
-
- var a = Math.min(min, max);
- var b = Math.max(min, max);
-
- if (Math.abs(a - b) === 1) {
- var result = min + '|' + max;
- if (options.capture) {
- return '(' + result + ')';
- }
- return result;
- }
-
- var isPadded = padding(min) || padding(max);
- var positives = [];
- var negatives = [];
-
- var tok = {min: min, max: max, a: a, b: b};
- if (isPadded) {
- tok.isPadded = isPadded;
- tok.maxLen = String(tok.max).length;
- }
-
- if (a < 0) {
- var newMin = b < 0 ? Math.abs(b) : 1;
- var newMax = Math.abs(a);
- negatives = splitToPatterns(newMin, newMax, tok, options);
- a = tok.a = 0;
- }
-
- if (b >= 0) {
- positives = splitToPatterns(a, b, tok, options);
- }
-
- tok.negatives = negatives;
- tok.positives = positives;
- tok.result = siftPatterns(negatives, positives, options);
-
- if (options.capture && (positives.length + negatives.length) > 1) {
- tok.result = '(' + tok.result + ')';
- }
-
- cache[key] = tok;
- return tok.result;
- }
-
- function siftPatterns(neg, pos, options) {
- var onlyNegative = filterPatterns(neg, pos, '-', false, options) || [];
- var onlyPositive = filterPatterns(pos, neg, '', false, options) || [];
- var intersected = filterPatterns(neg, pos, '-?', true, options) || [];
- var subpatterns = onlyNegative.concat(intersected).concat(onlyPositive);
- return subpatterns.join('|');
- }
-
- function splitToRanges(min, max) {
- min = Number(min);
- max = Number(max);
-
- var nines = 1;
- var stops = [max];
- var stop = +countNines(min, nines);
-
- while (min <= stop && stop <= max) {
- stops = push(stops, stop);
- nines += 1;
- stop = +countNines(min, nines);
- }
-
- var zeros = 1;
- stop = countZeros(max + 1, zeros) - 1;
-
- while (min < stop && stop <= max) {
- stops = push(stops, stop);
- zeros += 1;
- stop = countZeros(max + 1, zeros) - 1;
- }
-
- stops.sort(compare);
- return stops;
- }
-
- /**
- * Convert a range to a regex pattern
- * @param {Number} `start`
- * @param {Number} `stop`
- * @return {String}
- */
-
- function rangeToPattern(start, stop, options) {
- if (start === stop) {
- return {pattern: String(start), digits: []};
- }
-
- var zipped = zip(String(start), String(stop));
- var len = zipped.length, i = -1;
-
- var pattern = '';
- var digits = 0;
-
- while (++i < len) {
- var numbers = zipped[i];
- var startDigit = numbers[0];
- var stopDigit = numbers[1];
-
- if (startDigit === stopDigit) {
- pattern += startDigit;
-
- } else if (startDigit !== '0' || stopDigit !== '9') {
- pattern += toCharacterClass(startDigit, stopDigit);
-
- } else {
- digits += 1;
- }
- }
-
- if (digits) {
- pattern += options.shorthand ? '\\d' : '[0-9]';
- }
-
- return { pattern: pattern, digits: [digits] };
- }
-
- function splitToPatterns(min, max, tok, options) {
- var ranges = splitToRanges(min, max);
- var len = ranges.length;
- var idx = -1;
-
- var tokens = [];
- var start = min;
- var prev;
-
- while (++idx < len) {
- var range = ranges[idx];
- var obj = rangeToPattern(start, range, options);
- var zeros = '';
-
- if (!tok.isPadded && prev && prev.pattern === obj.pattern) {
- if (prev.digits.length > 1) {
- prev.digits.pop();
- }
- prev.digits.push(obj.digits[0]);
- prev.string = prev.pattern + toQuantifier(prev.digits);
- start = range + 1;
- continue;
- }
-
- if (tok.isPadded) {
- zeros = padZeros(range, tok);
- }
-
- obj.string = zeros + obj.pattern + toQuantifier(obj.digits);
- tokens.push(obj);
- start = range + 1;
- prev = obj;
- }
-
- return tokens;
- }
-
- function filterPatterns(arr, comparison, prefix, intersection, options) {
- var res = [];
-
- for (var i = 0; i < arr.length; i++) {
- var tok = arr[i];
- var ele = tok.string;
-
- if (options.relaxZeros !== false) {
- if (prefix === '-' && ele.charAt(0) === '0') {
- if (ele.charAt(1) === '{') {
- ele = '0*' + ele.replace(/^0\{\d+\}/, '');
- } else {
- ele = '0*' + ele.slice(1);
- }
- }
- }
-
- if (!intersection && !contains(comparison, 'string', ele)) {
- res.push(prefix + ele);
- }
-
- if (intersection && contains(comparison, 'string', ele)) {
- res.push(prefix + ele);
- }
- }
- return res;
- }
-
- /**
- * Zip strings (`for in` can be used on string characters)
- */
-
- function zip(a, b) {
- var arr = [];
- for (var ch in a) arr.push([a[ch], b[ch]]);
- return arr;
- }
-
- function compare(a, b) {
- return a > b ? 1 : b > a ? -1 : 0;
- }
-
- function push(arr, ele) {
- if (arr.indexOf(ele) === -1) arr.push(ele);
- return arr;
- }
-
- function contains(arr, key, val) {
- for (var i = 0; i < arr.length; i++) {
- if (arr[i][key] === val) {
- return true;
- }
- }
- return false;
- }
-
- function countNines(min, len) {
- return String(min).slice(0, -len) + repeat('9', len);
- }
-
- function countZeros(integer, zeros) {
- return integer - (integer % Math.pow(10, zeros));
- }
-
- function toQuantifier(digits) {
- var start = digits[0];
- var stop = digits[1] ? (',' + digits[1]) : '';
- if (!stop && (!start || start === 1)) {
- return '';
- }
- return '{' + start + stop + '}';
- }
-
- function toCharacterClass(a, b) {
- return '[' + a + ((b - a === 1) ? '' : '-') + b + ']';
- }
-
- function padding(str) {
- return /^-?(0+)\d/.exec(str);
- }
-
- function padZeros(val, tok) {
- if (tok.isPadded) {
- var diff = Math.abs(tok.maxLen - String(val).length);
- switch (diff) {
- case 0:
- return '';
- case 1:
- return '0';
- default: {
- return '0{' + diff + '}';
- }
- }
- }
- return val;
- }
-
- /**
- * Expose `toRegexRange`
- */
-
- module.exports = toRegexRange;
|