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- 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 [];
-
- // I don't know why Bash 4.3 does this, but it does.
- // Anything starting with {} will have the first two bytes preserved
- // but *only* at the top level, so {},a}b will not expand to anything,
- // but a{},b}c will be expanded to [a}c,abc].
- // One could argue that this is a bug in Bash, but since the goal of
- // this module is to match Bash's rules, we escape a leading {}
- if (str.substr(0, 2) === '{}') {
- str = '\\{\\}' + str.substr(2);
- }
-
- 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 = m.body.indexOf(',') >= 0;
- 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;
- }
-
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