Boolean reduction via _.every, _.reduce, _.forEach, vanilla js

speedTest.coffee

trues = (n) -> [1..n].map Boolean

# array of functions to be speed tested
tests = [
  [
    (
      (bools) -> _.every bools # .097ms
    )
    trues(1000)
    '1'
  ]
  [
    (
      (bools) ->
        bools.reduce (p, n) -> # .161ms
          return false unless n
          p or n
        , false
    )
    trues(1000)
    '2'
  ]
  [
    (
      (bools) ->
        bools.forEach (b) -> return false unless b # .141ms
        return true
    )
    trues(1000)
    '3'
  ]
  [
    (
      (bools) ->
        for b in bools
          return false unless b # FAST: .014ms
        return true
    )
    trues(1000)
    '4'
  ]
]

speedTestFn = (fn, arg, label) ->
  console.time label
  fn(arg)
  console.timeEnd label

results = []

tests.forEach ([fn, arg, label]) ->
  results = speedTestFn fn, arg, label

@bcherny the while(i--) performs the same as the vanilla for loop.

tested unrolling the loops - seems like for is the best option - http://jsperf.com/reduce-vs-while-vs-for

Wow. Way to go on testing this. Any theories on the "why"? I think it's the function scope creation...