var concatMap = require('concat-map'); var balanced = require('balanced-match'); module.exports = expandTop; var escSlash = '\0SLASH'+Math.random()+'\0'; var escOpen = '\0OPEN'+Math.random()+'\0'; var escClose = '\0CLOSE'+Math.random()+'\0'; var escComma = '\0COMMA'+Math.random()+'\0'; var escPeriod = '\0PERIOD'+Math.random()+'\0'; function numeric(str) { return parseInt(str, 10) == str ? parseInt(str, 10) : str.charCodeAt(0); } function escapeBraces(str) { return str.split('\\\\').join(escSlash) .split('\\{').join(escOpen) .split('\\}').join(escClose) .split('\\,').join(escComma) .split('\\.').join(escPeriod); } function unescapeBraces(str) { return str.split(escSlash).join('\\') .split(escOpen).join('{') .split(escClose).join('}') .split(escComma).join(',') .split(escPeriod).join('.'); } // Basically just str.split(","), but handling cases // where we have nested braced sections, which should be // treated as individual members, like {a,{b,c},d} function parseCommaParts(str) { if (!str) return ['']; var parts = []; var m = balanced('{', '}', str); if (!m) return str.split(','); var pre = m.pre; var body = m.body; var post = m.post; var p = pre.split(','); p[p.length-1] += '{' + body + '}'; var postParts = parseCommaParts(post); if (post.length) { p[p.length-1] += postParts.shift(); p.push.apply(p, postParts); } parts.push.apply(parts, p); return parts; } function expandTop(str) { if (!str) return []; return expand(escapeBraces(str), true).map(unescapeBraces); } function identity(e) { return e; } function embrace(str) { return '{' + str + '}'; } function isPadded(el) { return /^-?0\d/.test(el); } function lte(i, y) { return i <= y; } function gte(i, y) { return i >= y; } function expand(str, isTop) { var expansions = []; var m = balanced('{', '}', str); if (!m || /\$$/.test(m.pre)) return [str]; var isNumericSequence = /^-?\d+\.\.-?\d+(?:\.\.-?\d+)?$/.test(m.body); var isAlphaSequence = /^[a-zA-Z]\.\.[a-zA-Z](?:\.\.-?\d+)?$/.test(m.body); var isSequence = isNumericSequence || isAlphaSequence; var isOptions = /^(.*,)+(.+)?$/.test(m.body); if (!isSequence && !isOptions) { // {a},b} if (m.post.match(/,.*\}/)) { str = m.pre + '{' + m.body + escClose + m.post; return expand(str); } return [str]; } var n; if (isSequence) { n = m.body.split(/\.\./); } else { n = parseCommaParts(m.body); if (n.length === 1) { // x{{a,b}}y ==> x{a}y x{b}y n = expand(n[0], false).map(embrace); if (n.length === 1) { var post = m.post.length ? expand(m.post, false) : ['']; return post.map(function(p) { return m.pre + n[0] + p; }); } } } // at this point, n is the parts, and we know it's not a comma set // with a single entry. // no need to expand pre, since it is guaranteed to be free of brace-sets var pre = m.pre; var post = m.post.length ? expand(m.post, false) : ['']; var N; if (isSequence) { var x = numeric(n[0]); var y = numeric(n[1]); var width = Math.max(n[0].length, n[1].length) var incr = n.length == 3 ? Math.abs(numeric(n[2])) : 1; var test = lte; var reverse = y < x; if (reverse) { incr *= -1; test = gte; } var pad = n.some(isPadded); N = []; for (var i = x; test(i, y); i += incr) { var c; if (isAlphaSequence) { c = String.fromCharCode(i); if (c === '\\') c = ''; } else { c = String(i); if (pad) { var need = width - c.length; if (need > 0) { var z = new Array(need + 1).join('0'); if (i < 0) c = '-' + z + c.slice(1); else c = z + c; } } } N.push(c); } } else { N = concatMap(n, function(el) { return expand(el, false) }); } for (var j = 0; j < N.length; j++) { for (var k = 0; k < post.length; k++) { var expansion = pre + N[j] + post[k]; if (!isTop || isSequence || expansion) expansions.push(expansion); } } return expansions; }