console.sprintf()

console.sprintf.js

// Sprintf from http://www.diveintojavascript.com/projects/javascript-sprintf
!function(console) {
  var sprintf = (function() {
    function get_type(variable) {
      return Object.prototype.toString.call(variable).slice(8, -1).toLowerCase();
    }

    var str_repeat = function(str, qty, separator){
      // ~~var — is the fastest available way to convert anything to Integer in javascript.
      // We'll use it extensively in this lib.
      str += ''; qty = ~~qty;
      for (var repeat = []; qty > 0; repeat[--qty] = str) {}
      return repeat.join(separator == null ? '' : separator);
    };

    var str_format = function() {
      if (!str_format.cache.hasOwnProperty(arguments[0][0])) {
        str_format.cache[arguments[0][0]] = str_format.parse(arguments[0][0]);
      }
      return str_format.format.call(null, str_format.cache[arguments[0][0]], arguments[0]);
    };

    str_format.format = function(parse_tree, argv) {
      var cursor = 1, tree_length = parse_tree.length, node_type = '', arg, output = [], i, k, match, pad, pad_character, pad_length;
      for (i = 0; i < tree_length; i++) {
        node_type = get_type(parse_tree[i]);
        if (node_type === 'string') {
          output.push(parse_tree[i]);
        }
        else if (node_type === 'array') {
          match = parse_tree[i]; // convenience purposes only
          if (match[2]) { // keyword argument
            arg = argv[cursor];
            for (k = 0; k < match[2].length; k++) {
              if (!arg.hasOwnProperty(match[2][k])) {
                throw new Error(sprintf('[console.sprintf] property "%s" does not exist', match[2][k]));
              }
              arg = arg[match[2][k]];
            }
          } else if (match[1]) { // positional argument (explicit)
            arg = argv[match[1]];
          }
          else { // positional argument (implicit)
            arg = argv[cursor++];
          }

          if (/[^s]/.test(match[8]) && (get_type(arg) != 'number')) {
            throw new Error(sprintf('[console.sprintf] expecting number but found %s', get_type(arg)));
          }
          switch (match[8]) {
            case 'b': arg = arg.toString(2); break;
            case 'c': arg = String.fromCharCode(arg); break;
            case 'd': arg = parseInt(arg, 10); break;
            case 'e': arg = match[7] ? arg.toExponential(match[7]) : arg.toExponential(); break;
            case 'f': arg = match[7] ? parseFloat(arg).toFixed(match[7]) : parseFloat(arg); break;
            case 'o': arg = arg.toString(8); break;
            case 's': arg = ((arg = String(arg)) && match[7] ? arg.substring(0, match[7]) : arg); break;
            case 'u': arg = Math.abs(arg); break;
            case 'x': arg = arg.toString(16); break;
            case 'X': arg = arg.toString(16).toUpperCase(); break;
          }
          arg = (/[def]/.test(match[8]) && match[3] && arg >= 0 ? '+'+ arg : arg);
          pad_character = match[4] ? match[4] == '0' ? '0' : match[4].charAt(1) : ' ';
          pad_length = match[6] - String(arg).length;
          pad = match[6] ? str_repeat(pad_character, pad_length) : '';
          output.push(match[5] ? arg + pad : pad + arg);
        }
      }

      if (typeof argv === 'string') {
        return argv
      } else {
        var outputLength = output.length
        return output.join('').split().concat(
          [].filter.call(argv, function(arg, i) {
            if (i >= outputLength)
              return arg
          })
        )
      }
    };

    str_format.cache = {};

    str_format.parse = function(fmt) {
      var _fmt = fmt, match = [], parse_tree = [], arg_names = 0;
      while (_fmt) {
        if ((match = /^[^\x25]+/.exec(_fmt)) !== null) {
          parse_tree.push(match[0]);
        }
        else if ((match = /^\x25{2}/.exec(_fmt)) !== null) {
          parse_tree.push('%');
        }
        else if ((match = /^\x25(?:([1-9]\d*)\$|\(([^\)]+)\))?(\+)?(0|'[^$])?(-)?(\d+)?(?:\.(\d+))?([b-fosuxX])/.exec(_fmt)) !== null) {
          if (match[2]) {
            arg_names |= 1;
            var field_list = [], replacement_field = match[2], field_match = [];
            if ((field_match = /^([a-z_][a-z_\d]*)/i.exec(replacement_field)) !== null) {
              field_list.push(field_match[1]);
              while ((replacement_field = replacement_field.substring(field_match[0].length)) !== '') {
                if ((field_match = /^\.([a-z_][a-z_\d]*)/i.exec(replacement_field)) !== null) {
                  field_list.push(field_match[1]);
                }
                else if ((field_match = /^\[(\d+)\]/.exec(replacement_field)) !== null) {
                  field_list.push(field_match[1]);
                }
                else {
                  throw new Error('[console.sprintf] huh?');
                }
              }
            }
            else {
              throw new Error('[console.sprintf] huh?');
            }
            match[2] = field_list;
          }
          else {
            arg_names |= 2;
          }
          if (arg_names === 3) {
            throw new Error('[console.sprintf] mixing positional and named placeholders is not (yet) supported');
          }
          parse_tree.push(match);
        }
        else {
          throw new Error('[console.sprintf] huh?');
        }
        _fmt = _fmt.substring(match[0].length);
      }
      return parse_tree;
    };

    return str_format;
  })();

  console.sprintf = function() {
    console.log.apply(console, sprintf(arguments))
  }
}(console)

console.sprintf.min.js

!function(a){var b=function(){function a(a){return Object.prototype.toString.call(a).slice(8,-1).toLowerCase()}var c=function(a,b,c){a+="",b=~~b;for(var d=[];b>0;d[--b]=a);return d.join(c==null?"":c)},d=function(){return d.cache.hasOwnProperty(arguments[0][0])||(d.cache[arguments[0][0]]=d.parse(arguments[0][0])),d.format.call(null,d.cache[arguments[0][0]],arguments[0])};return d.format=function(d,e){var f=1,g=d.length,h="",i,j=[],k,l,m,n,o,p;for(k=0;k<g;k++){h=a(d[k]);if(h==="string")j.push(d[k]);else if(h==="array"){m=d[k];if(m[2]){i=e[f];for(l=0;l<m[2].length;l++){if(!i.hasOwnProperty(m[2][l]))throw new Error(b('[console.sprintf] property "%s" does not exist',m[2][l]));i=i[m[2][l]]}}else m[1]?i=e[m[1]]:i=e[f++];if(/[^s]/.test(m[8])&&a(i)!="number")throw new Error(b("[console.sprintf] expecting number but found %s",a(i)));switch(m[8]){case"b":i=i.toString(2);break;case"c":i=String.fromCharCode(i);break;case"d":i=parseInt(i,10);break;case"e":i=m[7]?i.toExponential(m[7]):i.toExponential();break;case"f":i=m[7]?parseFloat(i).toFixed(m[7]):parseFloat(i);break;case"o":i=i.toString(8);break;case"s":i=(i=String(i))&&m[7]?i.substring(0,m[7]):i;break;case"u":i=Math.abs(i);break;case"x":i=i.toString(16);break;case"X":i=i.toString(16).toUpperCase()}i=/[def]/.test(m[8])&&m[3]&&i>=0?"+"+i:i,o=m[4]?m[4]=="0"?"0":m[4].charAt(1):" ",p=m[6]-String(i).length,n=m[6]?c(o,p):"",j.push(m[5]?i+n:n+i)}}if(typeof e=="string")return e;var q=j.length;return j.join("").split().concat([].filter.call(e,function(a,b){if(b>=q)return a}))},d.cache={},d.parse=function(a){var b=a,c=[],d=[],e=0;while(b){if((c=/^[^\x25]+/.exec(b))!==null)d.push(c[0]);else if((c=/^\x25{2}/.exec(b))!==null)d.push("%");else{if((c=/^\x25(?:([1-9]\d*)\$|\(([^\)]+)\))?(\+)?(0|'[^$])?(-)?(\d+)?(?:\.(\d+))?([b-fosuxX])/.exec(b))===null)throw new Error("[console.sprintf] huh?");if(c[2]){e|=1;var f=[],g=c[2],h=[];if((h=/^([a-z_][a-z_\d]*)/i.exec(g))===null)throw new Error("[console.sprintf] huh?");f.push(h[1]);while((g=g.substring(h[0].length))!=="")if((h=/^\.([a-z_][a-z_\d]*)/i.exec(g))!==null)f.push(h[1]);else{if((h=/^\[(\d+)\]/.exec(g))===null)throw new Error("[console.sprintf] huh?");f.push(h[1])}c[2]=f}else e|=2;if(e===3)throw new Error("[console.sprintf] mixing positional and named placeholders is not (yet) supported");d.push(c)}b=b.substring(c[0].length)}return d},d}();a.sprintf=function(){a.log.apply(a,b(arguments))}}(console);