Small converter utility for converting between provided values. Its parameters must be the type names and the type values association

typeConverter.js

function Converter(types, values) {
  var associations = {},
      values = values,
      types = types;

  return function(baseValue){
    types.forEach(function(type){
      associations[type] = {
        to : types.reduce(function(current, previous){
          
          if(type == previous){
            return current;
          }

          var index1 = types.indexOf(type) + 1,
              index2 = types.indexOf(previous) + 1;

          if(index1 > index2){
            var reversed = true;
            index2 = [index1, index1 = index2][0];
          }

          current[previous] = values
                                .slice(index1, index2)
                                .reduce(function(current, previous){
                                  return current * previous;
                                }, 1) * baseValue;
          
          if(reversed){
            current[previous] = (1 / current[previous]) * baseValue;
          }
          return current;
        }, {})
      }
    });
    return associations;
  }
}

Example usage

var lengthConverter = new Converter(['mile', 'yard', 'foot', 'inch', 'cm'], [1, 1760, 3, 12, 2.54])
lengthConverter(10).mile.to.yard; // prints 17600
lengthConverter(10).cm.to.inch; //prints 3.93700787