Simplistic pattern matching in less than 25 lines using switch statement

pattern-matching.js

'use strict';

const types = {
  [Number ] : 'number',
  [String ] : 'string',
  [Boolean] : 'boolean',
  [Object ] : 'object'
};

function of(...typesToCheck) {
  let typeNames = Object.keys(types).map(key => types[key]);
  let patternMatchingString = typesToCheck
    .map((type) => typeof type === 'function' ? types[type] : type )
    .map((typeName) => typeNames.indexOf(typeName))
    .join(' ');

  return patternMatchingString;
}

function match(...args) {
  return of(...args.map(arg => typeof arg));
}

// Example:

function doStuff(a, b) {
  switch(match(a, b)) {
    case of(Number, Number ) : return true;
    case of(String, String ) : return 'strings';
    case of(String, Boolean) : return 'stringbool';
    case of(Object, Object ) : return 'objects';
    default                  : return false;
  }
}

console.log(doStuff(2, 2));      //=> true
console.log(doStuff('a', 'b'));  //=> 'strings'
console.log(doStuff('s', true)); //=> 'stringbool'
console.log(doStuff({}, []));    //=> 'objects'
console.log(doStuff('asdf'));    //=> false