regex vs slice (v10)

Revision 10 of this benchmark created by mauk on

Description

It is not important to get fast results, but to make it fast to use. So I added some code that calls the functions and to make life harder for V8 by supplying different types.

The returned string needs to be compared byte-for-byte. This new version returns a string constant, which is faster because they compare-by-reference.

The hash lookup should also be fast because the returned '[object Object]' strings are internally cached literals. However, it isn't.

Preparation HTML

<script>
  var toTypeRegExp = function(obj) {
      return ({}).toString.call(obj).match(/\s([a-z|A-Z]+)/)[1];
      }
      
  var toTypeSlice = function(obj) {
      return ({}).toString.call(obj).slice(8, -1);
      }
      
  var toTypeSliceProto = function(obj) {
      return Object.prototype.toString.call(obj).slice(8, -1);
      }
      
  var oproto = Object.prototype.toString;
  var toTypeSliceCachedProto = function(obj) {
      return oproto.call(obj).slice(8, -1);
      }

  var map = {
          '[object String]': 'String',
          '[object Number]': 'Number',
          '[object Object]': 'Object',
          '[object Array]': 'Array',
          // etc
          };

  var toTypeHashed = function(obj) {
      return map[oproto.call(obj)];
      };

  var teststuff = [ [1,2], 'Array', {a:1}, "Object", 1, "Number", "Abc", "String" ];

  var runtest = function(f) {
      for (var i=0; i<teststuff.length; i+=2) {
        if (f(teststuff[i]) !== teststuff[i+1])
           throw i+": "+ teststuff[i]+" got "+f(teststuff[i])+", expected "+teststuff[i+1];
      }
  };
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
hash lookup, string literals
runtest(toTypeHashed)
ready
slice (literal)
runtest(toTypeSlice)
ready
slice (proto)
runtest(toTypeSliceProto)
ready
slice (cached proto)
runtest(toTypeSliceCachedProto)
ready
regex
runtest(toTypeRegExp)
ready

Revisions

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