source: trip-planner-front/node_modules/extsprintf/lib/extsprintf.js@ 6a3a178

/*
 * extsprintf.js: extended POSIX-style sprintf
 */

var mod_assert = require('assert');
var mod_util = require('util');

/*
 * Public interface
 */
exports.sprintf = jsSprintf;
exports.printf = jsPrintf;
exports.fprintf = jsFprintf;

/*
 * Stripped down version of s[n]printf(3c).  We make a best effort to throw an
 * exception when given a format string we don't understand, rather than
 * ignoring it, so that we won't break existing programs if/when we go implement
 * the rest of this.
 *
 * This implementation currently supports specifying
 *      - field alignment ('-' flag),
 *      - zero-pad ('0' flag)
 *      - always show numeric sign ('+' flag),
 *      - field width
 *      - conversions for strings, decimal integers, and floats (numbers).
 *      - argument size specifiers.  These are all accepted but ignored, since
 *        Javascript has no notion of the physical size of an argument.
 *
 * Everything else is currently unsupported, most notably precision, unsigned
 * numbers, non-decimal numbers, and characters.
 */
function jsSprintf(fmt)
{
        var regex = [
            '([^%]*)',                          /* normal text */
            '%',                                /* start of format */
            '([\'\\-+ #0]*?)',                  /* flags (optional) */
            '([1-9]\\d*)?',                     /* width (optional) */
            '(\\.([1-9]\\d*))?',                /* precision (optional) */
            '[lhjztL]*?',                       /* length mods (ignored) */
            '([diouxXfFeEgGaAcCsSp%jr])'        /* conversion */
        ].join('');

        var re = new RegExp(regex);
        var args = Array.prototype.slice.call(arguments, 1);
        var flags, width, precision, conversion;
        var left, pad, sign, arg, match;
        var ret = '';
        var argn = 1;

        mod_assert.equal('string', typeof (fmt));

        while ((match = re.exec(fmt)) !== null) {
                ret += match[1];
                fmt = fmt.substring(match[0].length);

                flags = match[2] || '';
                width = match[3] || 0;
                precision = match[4] || '';
                conversion = match[6];
                left = false;
                sign = false;
                pad = ' ';

                if (conversion == '%') {
                        ret += '%';
                        continue;
                }

                if (args.length === 0)
                        throw (new Error('too few args to sprintf'));

                arg = args.shift();
                argn++;

                if (flags.match(/[\' #]/))
                        throw (new Error(
                            'unsupported flags: ' + flags));

                if (precision.length > 0)
                        throw (new Error(
                            'non-zero precision not supported'));

                if (flags.match(/-/))
                        left = true;

                if (flags.match(/0/))
                        pad = '0';

                if (flags.match(/\+/))
                        sign = true;

                switch (conversion) {
                case 's':
                        if (arg === undefined || arg === null)
                                throw (new Error('argument ' + argn +
                                    ': attempted to print undefined or null ' +
                                    'as a string'));
                        ret += doPad(pad, width, left, arg.toString());
                        break;

                case 'd':
                        arg = Math.floor(arg);
                        /*jsl:fallthru*/
                case 'f':
                        sign = sign && arg > 0 ? '+' : '';
                        ret += sign + doPad(pad, width, left,
                            arg.toString());
                        break;

                case 'x':
                        ret += doPad(pad, width, left, arg.toString(16));
                        break;

                case 'j': /* non-standard */
                        if (width === 0)
                                width = 10;
                        ret += mod_util.inspect(arg, false, width);
                        break;

                case 'r': /* non-standard */
                        ret += dumpException(arg);
                        break;

                default:
                        throw (new Error('unsupported conversion: ' +
                            conversion));
                }
        }

        ret += fmt;
        return (ret);
}

function jsPrintf() {
        var args = Array.prototype.slice.call(arguments);
        args.unshift(process.stdout);
        jsFprintf.apply(null, args);
}

function jsFprintf(stream) {
        var args = Array.prototype.slice.call(arguments, 1);
        return (stream.write(jsSprintf.apply(this, args)));
}

function doPad(chr, width, left, str)
{
        var ret = str;

        while (ret.length < width) {
                if (left)
                        ret += chr;
                else
                        ret = chr + ret;
        }

        return (ret);
}

/*
 * This function dumps long stack traces for exceptions having a cause() method.
 * See node-verror for an example.
 */
function dumpException(ex)
{
        var ret;

        if (!(ex instanceof Error))
                throw (new Error(jsSprintf('invalid type for %%r: %j', ex)));

        /* Note that V8 prepends "ex.stack" with ex.toString(). */
        ret = 'EXCEPTION: ' + ex.constructor.name + ': ' + ex.stack;

        if (ex.cause && typeof (ex.cause) === 'function') {
                var cex = ex.cause();
                if (cex) {
                        ret += '\nCaused by: ' + dumpException(cex);
                }
        }

        return (ret);
}