/*!
* fill-range <https://github.com/jonschlinkert/fill-range>
*
* Copyright (c) 2014-2015, Jon Schlinkert.
* Licensed under the MIT License.
*/
'use strict';
var isObject = require('isobject');
var isNumber = require('is-number');
var randomize = require('randomatic');
var repeatStr = require('repeat-string');
var repeat = require('repeat-element');
/**
* Expose `fillRange`
*/
module.exports = fillRange;
/**
* Return a range of numbers or letters.
*
* @param {String} `a` Start of the range
* @param {String} `b` End of the range
* @param {String} `step` Increment or decrement to use.
* @param {Function} `fn` Custom function to modify each element in the range.
* @return {Array}
*/
function fillRange(a, b, step, options, fn) {
if (a == null || b == null) {
throw new Error('fill-range expects the first and second args to be strings.');
}
if (typeof step === 'function') {
fn = step; options = {}; step = null;
}
if (typeof options === 'function') {
fn = options; options = {};
}
if (isObject(step)) {
options = step; step = '';
}
var expand, regex = false, sep = '';
var opts = options || {};
if (typeof opts.silent === 'undefined') {
opts.silent = true;
}
step = step || opts.step;
// store a ref to unmodified arg
var origA = a, origB = b;
b = (b.toString() === '-0') ? 0 : b;
if (opts.optimize || opts.makeRe) {
step = step ? (step += '~') : step;
expand = true;
regex = true;
sep = '~';
}
// handle special step characters
if (typeof step === 'string') {
var match = stepRe().exec(step);
if (match) {
var i = match.index;
var m = match[0];
// repeat string
if (m === '+') {
return repeat(a, b);
// randomize a, `b` times
} else if (m === '?') {
return [randomize(a, b)];
// expand right, no regex reduction
} else if (m === '>') {
step = step.substr(0, i) + step.substr(i + 1);
expand = true;
// expand to an array, or if valid create a reduced
// string for a regex logic `or`
} else if (m === '|') {
step = step.substr(0, i) + step.substr(i + 1);
expand = true;
regex = true;
sep = m;
// expand to an array, or if valid create a reduced
// string for a regex range
} else if (m === '~') {
step = step.substr(0, i) + step.substr(i + 1);
expand = true;
regex = true;
sep = m;
}
} else if (!isNumber(step)) {
if (!opts.silent) {
throw new TypeError('fill-range: invalid step.');
}
return null;
}
}
if (/[.&*()[\]^%$#@!]/.test(a) || /[.&*()[\]^%$#@!]/.test(b)) {
if (!opts.silent) {
throw new RangeError('fill-range: invalid range arguments.');
}
return null;
}
// has neither a letter nor number, or has both letters and numbers
// this needs to be after the step logic
if (!noAlphaNum(a) || !noAlphaNum(b) || hasBoth(a) || hasBoth(b)) {
if (!opts.silent) {
throw new RangeError('fill-range: invalid range arguments.');
}
return null;
}
// validate arguments
var isNumA = isNumber(zeros(a));
var isNumB = isNumber(zeros(b));
if ((!isNumA && isNumB) || (isNumA && !isNumB)) {
if (!opts.silent) {
throw new TypeError('fill-range: first range argument is incompatible with second.');
}
return null;
}
// by this point both are the same, so we
// can use A to check going forward.
var isNum = isNumA;
var num = formatStep(step);
// is the range alphabetical? or numeric?
if (isNum) {
// if numeric, coerce to an integer
a = +a; b = +b;
} else {
// otherwise, get the charCode to expand alpha ranges
a = a.charCodeAt(0);
b = b.charCodeAt(0);
}
// is the pattern descending?
var isDescending = a > b;
// don't create a character class if the args are < 0
if (a < 0 || b < 0) {
expand = false;
regex = false;
}
// detect padding
var padding = isPadded(origA, origB);
var res, pad, arr = [];
var ii = 0;
// character classes, ranges and logical `or`
if (regex) {
if (shouldExpand(a, b, num, isNum, padding, opts)) {
// make sure the correct separator is used
if (sep === '|' || sep === '~') {
sep = detectSeparator(a, b, num, isNum, isDescending);
}
return wrap([origA, origB], sep, opts);
}
}
while (isDescending ? (a >= b) : (a <= b)) {
if (padding && isNum) {
pad = padding(a);
}
// custom function
if (typeof fn === 'function') {
res = fn(a, isNum, pad, ii++);
// letters
} else if (!isNum) {
if (regex && isInvalidChar(a)) {
res = null;
} else {
res = String.fromCharCode(a);
}
// numbers
} else {
res = formatPadding(a, pad);
}
// add result to the array, filtering any nulled values
if (res !== null) arr.push(res);
// increment or decrement
if (isDescending) {
a -= num;
} else {
a += num;
}
}
// now that the array is expanded, we need to handle regex
// character classes, ranges or logical `or` that wasn't
// already handled before the loop
if ((regex || expand) && !opts.noexpand) {
// make sure the correct separator is used
if (sep === '|' || sep === '~') {
sep = detectSeparator(a, b, num, isNum, isDescending);
}
if (arr.length === 1 || a < 0 || b < 0) { return arr; }
return wrap(arr, sep, opts);
}
return arr;
}
/**
* Wrap the string with the correct regex
* syntax.
*/
function wrap(arr, sep, opts) {
if (sep === '~') { sep = '-'; }
var str = arr.join(sep);
var pre = opts && opts.regexPrefix;
// regex logical `or`
if (sep === '|') {
str = pre ? pre + str : str;
str = '(' + str + ')';
}
// regex character class
if (sep === '-') {
str = (pre && pre === '^')
? pre + str
: str;
str = '[' + str + ']';
}
return [str];
}
/**
* Check for invalid characters
*/
function isCharClass(a, b, step, isNum, isDescending) {
if (isDescending) { return false; }
if (isNum) { return a <= 9 && b <= 9; }
if (a < b) { return step === 1; }
return false;
}
/**
* Detect the correct separator to use
*/
function shouldExpand(a, b, num, isNum, padding, opts) {
if (isNum && (a > 9 || b > 9)) { return false; }
return !padding && num === 1 && a < b;
}
/**
* Detect the correct separator to use
*/
function detectSeparator(a, b, step, isNum, isDescending) {
var isChar = isCharClass(a, b, step, isNum, isDescending);
if (!isChar) {
return '|';
}
return '~';
}
/**
* Correctly format the step based on type
*/
function formatStep(step) {
return Math.abs(step >> 0) || 1;
}
/**
* Format padding, taking leading `-` into account
*/
function formatPadding(ch, pad) {
var res = pad ? pad + ch : ch;
if (pad && ch.toString().charAt(0) === '-') {
res = '-' + pad + ch.toString().substr(1);
}
return res.toString();
}
/**
* Check for invalid characters
*/
function isInvalidChar(str) {
var ch = toStr(str);
return ch === '\\'
|| ch === '['
|| ch === ']'
|| ch === '^'
|| ch === '('
|| ch === ')'
|| ch === '`';
}
/**
* Convert to a string from a charCode
*/
function toStr(ch) {
return String.fromCharCode(ch);
}
/**
* Step regex
*/
function stepRe() {
return /\?|>|\||\+|\~/g;
}
/**
* Return true if `val` has either a letter
* or a number
*/
function noAlphaNum(val) {
return /[a-z0-9]/i.test(val);
}
/**
* Return true if `val` has both a letter and
* a number (invalid)
*/
function hasBoth(val) {
return /[a-z][0-9]|[0-9][a-z]/i.test(val);
}
/**
* Normalize zeros for checks
*/
function zeros(val) {
if (/^-*0+$/.test(val.toString())) {
return '0';
}
return val;
}
/**
* Return true if `val` has leading zeros,
* or a similar valid pattern.
*/
function hasZeros(val) {
return /[^.]\.|^-*0+[0-9]/.test(val);
}
/**
* If the string is padded, returns a curried function with
* the a cached padding string, or `false` if no padding.
*
* @param {*} `origA` String or number.
* @return {String|Boolean}
*/
function isPadded(origA, origB) {
if (hasZeros(origA) || hasZeros(origB)) {
var alen = length(origA);
var blen = length(origB);
var len = alen >= blen
? alen
: blen;
return function (a) {
return repeatStr('0', len - length(a));
};
}
return false;
}
/**
* Get the string length of `val`
*/
function length(val) {
return val.toString().length;
}