patternCompiler.js

function compile (pattern, mapping) {

      pattern = pattern || '';

      var i,
        ch,
        last,
        attrName,
        sequenceLength = 0,
        len = pattern.length,
        builder = [],
        attrsCharsMapping = {},
        isUpper.
        shouldAppend;

      for (attrName in mapping) {
        if (mapping.hasOwnProperty(attrName)) {
          attrsCharsMapping[attrName.toLowerCase()] = attrsCharsMapping[attrName.toUpperCase()] = mapping[attrName];
        }
      }

      last = pattern[0];

      for (i = 0; i <= len; i++) {
        ch = pattern[i];
        attrName = attrsCharsMapping[last];
        isUpper = (last || '').toUpperCase() === last;
        shouldAppend = !attrName || (i > 0 && isUpper || ch !== last);
        if (shouldAppend) {
          if (attrName) {
            builder.push('(attrs.' + attrName + " || '')" + (isUpper ? '' : '.substr(0,' + sequenceLength + ')'));
          } else {
            builder.push("'" + last + "'");
          }
          sequenceLength = 1;
        } else {
          sequenceLength++;
        }
        last = ch;
      }
      
      var fnBody = 'return ' + builder.join(' + ') + ';';
      
      return new Function('attrs', fnBody)
};

///* EXAMPLE USAGE */
// var template = compile('Fl@D', {f: 'firstName', l: 'lastName', d: 'domain'});
// template ({firstName: 'Eyal', lastName: 'Weiss', domain: 'similartech.com'});
// template ({firstName: 'John', lastName: 'Doe', domain: 'domain.com'});