/**
* JavaScript printf/sprintf functions.
* http://hexmen.com/blog/2007/03/printf-sprintf/
*
* This code is unrestricted: you are free to use it however you like.
*
* The functions should work as expected, performing left or right alignment,
* truncating strings, outputting numbers with a required precision etc.
*
* For complex cases these functions follow the Perl implementations of
* (s)printf, allowing arguments to be passed out-of-order, and to set
* precision and output-length from other argument
*
* See http://perldoc.perl.org/functions/sprintf.html for more information.
*
* Implemented flags:
*
* - zero or space-padding (default: space)
* sprintf("%4d", 3) -> " 3"
* sprintf("%04d", 3) -> "0003"
*
* - left and right-alignment (default: right)
* sprintf("%3s", "a") -> " a"
* sprintf("%-3s", "b") -> "b "
*
* - out of order arguments (good for templates & message formats)
* sprintf("Estimate: %2$d units total: %1$.2f total", total, quantity)
*
* - binary, octal and hex prefixes (default: none)
* sprintf("%b", 13) -> "1101"
* sprintf("%#b", 13) -> "0b1101"
* sprintf("%#06x", 13) -> "0x000d"
*
* - positive number prefix (default: none)
* sprintf("%d", 3) -> "3"
* sprintf("%+d", 3) -> "+3"
* sprintf("% d", 3) -> " 3"
*
* - min/max width (with truncation); e.g. "%9.3s" and "%-9.3s"
* sprintf("%5s", "catfish") -> "catfish"
* sprintf("%.5s", "catfish") -> "catfi"
* sprintf("%5.3s", "catfish") -> " cat"
* sprintf("%-5.3s", "catfish") -> "cat "
*
* - precision (see note below); e.g. "%.2f"
* sprintf("%.3f", 2.1) -> "2.100"
* sprintf("%.3e", 2.1) -> "2.100e+0"
* sprintf("%.3g", 2.1) -> "2.10"
* sprintf("%.3p", 2.1) -> "2.1"
* sprintf("%.3p", '2.100') -> "2.10"
*
* Deviations from perl spec:
* - %n suppresses an argument
* - %p and %P act like %g, but without over-claiming accuracy:
* Compare:
* sprintf("%.3g", "2.1") -> "2.10"
* sprintf("%.3p", "2.1") -> "2.1"
*
* @version 2011.09.23
* @author Ash Searle
*/
function sprintf() {
function pad(str, len, chr, leftJustify) {
var padding = (str.length >= len) ? '' : Array(1 + len - str.length >>> 0).join(chr);
return leftJustify ? str + padding : padding + str;
}
function justify(value, prefix, leftJustify, minWidth, zeroPad) {
var diff = minWidth - value.length;
if (diff > 0) {
if (leftJustify || !zeroPad) {
value = pad(value, minWidth, ' ', leftJustify);
} else {
value = value.slice(0, prefix.length) + pad('', diff, '0', true) + value.slice(prefix.length);
}
}
return value;
}
var a = arguments, i = 0, format = a[i++];
return format.replace(sprintf.regex, function(substring, valueIndex, flags, minWidth, _, precision, type) {
if (substring == '%%') return '%';
// parse flags
var leftJustify = false, positivePrefix = '', zeroPad = false, prefixBaseX = false;
for (var j = 0; flags && j < flags.length; j++) switch (flags.charAt(j)) {
case ' ': positivePrefix = ' '; break;
case '+': positivePrefix = '+'; break;
case '-': leftJustify = true; break;
case '0': zeroPad = true; break;
case '#': prefixBaseX = true; break;
}
// parameters may be null, undefined, empty-string or real valued
// we want to ignore null, undefined and empty-string values
if (!minWidth) {
minWidth = 0;
} else if (minWidth == '*') {
minWidth = +a[i++];
} else if (minWidth.charAt(0) == '*') {
minWidth = +a[minWidth.slice(1, -1)];
} else {
minWidth = +minWidth;
}
// Note: undocumented perl feature:
if (minWidth < 0) {
minWidth = -minWidth;
leftJustify = true;
}
if (!isFinite(minWidth)) {
throw new Error('sprintf: (minimum-)width must be finite');
}
if (precision && precision.charAt(0) == '*') {
precision = +a[(precision == '*') ? i++ : precision.slice(1, -1)];
if (precision < 0) {
precision = null;
}
}
if (precision == null) {
precision = 'fFeE'.indexOf(type) > -1 ? 6 : (type == 'd') ? 0 : void(0);
} else {
precision = +precision;
}
// grab value using valueIndex if required?
var value = valueIndex ? a[valueIndex.slice(0, -1)] : a[i++];
var prefix, base;
switch (type) {
case 'c': value = String.fromCharCode(+value);
case 's': {
// If you'd rather treat nulls as empty-strings, uncomment next line:
// if (value == null) return '';
value = String(value);
if (precision != null) {
value = value.slice(0, precision);
}
prefix = '';
break;
}
case 'b': base = 2; break;
case 'o': base = 8; break;
case 'u': base = 10; break;
case 'x': case 'X': base = 16; break;
case 'i':
case 'd': {
var number = parseInt(+value);
if (isNaN(number)) {
return '';
}
prefix = number < 0 ? '-' : positivePrefix;
value = prefix + pad(String(Math.abs(number)), precision, '0', false);
break;
}
case 'e': case 'E':
case 'f': case 'F':
case 'g': case 'G':
case 'p': case 'P':
{
var number = +value;
if (isNaN(number)) {
return '';
}
prefix = number < 0 ? '-' : positivePrefix;
var method;
if ('p' != type.toLowerCase()) {
method = ['toExponential', 'toFixed', 'toPrecision']['efg'.indexOf(type.toLowerCase())];
} else {
// Count significant-figures, taking special-care of zeroes ('0' vs '0.00' etc.)
var sf = String(value).replace(/[eE].*|[^\d]/g, '');
sf = (number ? sf.replace(/^0+/,'') : sf).length;
precision = precision ? Math.min(precision, sf) : precision;
method = (!precision || precision <= sf) ? 'toPrecision' : 'toExponential';
}
var number_str = Math.abs(number)[method](precision);
// number_str = thousandSeparation ? thousand_separate(number_str): number_str;
value = prefix + number_str;
break;
}
case 'n': return '';
default: return substring;
}
if (base) {
// cast to non-negative integer:
var number = value >>> 0;
prefix = prefixBaseX && base != 10 && number && ['0b', '0', '0x'][base >> 3] || '';
value = prefix + pad(number.toString(base), precision || 0, '0', false);
}
var justified = justify(value, prefix, leftJustify, minWidth, zeroPad);
return ('EFGPX'.indexOf(type) > -1) ? justified.toUpperCase() : justified;
});
}
sprintf.regex = /%%|%(\d+\$)?([-+#0 ]*)(\*\d+\$|\*|\d+)?(\.(\*\d+\$|\*|\d+))?([scboxXuidfegpEGP])/g;
/**
* Trival printf implementation, probably only useful during page-load.
* Note: you may as well use "document.write(sprintf(....))" directly
*/
function printf() {
// delegate the work to sprintf in an IE5 friendly manner:
var i = 0, a = arguments, args = Array(arguments.length);
while (i < args.length) args[i] = 'a[' + (i++) + ']';
document.write(eval('sprintf(' + args + ')'));
}