Comment by jdmichal

11 years ago

I'm more disappointed that it doesn't short-circuit the operation at all. It applies all the functions, THEN it determines whether all of them passed. Even worse, it uses `every` (which does short-circuit) to determine that all the functions are, indeed, functions, but apparently the ability to use that function to determine whether every predicate passes was missed.

1 comment

jdmichal

jacobolus 11 years ago

It could have been a simple for loop with a break whenever one evaluates false. Blazing fast in every javascript engine, and easy to see all the code in one place.

Instead, it’s a slow tower of bloat, which you need to read 5 files to reason about.

Javascript implementation:

    function passAll() {
      var fns = [].slice.call(arguments);
      return function() {
        for (var i = 0, len = fns.length; i < len; i++) {
          if (!fns[i].apply(null, arguments)) { return false; }
        }
        return true;
      };
    }

Or Coffeescript (including the function check):

    passAll = (fns...) ->
        for fn in fns then if typeof fn isnt 'function'
            throw new TypeError 'all funcs should be functions'
        (args...) ->
            (return false if not fn args...) for fn in fns
            true