trobertson

var data = [0,1,2,3,4,5,6,7,8,9];

function test() {
  var g = window;
  g.result = [];
  for(var i = 0; i < data.length; i++) {
    if(data[i] % 2 === 0) {
      g.result.push(data[i]*2);
    }
  }

trobertson

#lang r5rs
;;;;
; From the paper:
;     Relational Programming in miniKanren:
;     Techniques, Applications, And Implementations
;     William E. Byrd
;;;;

;;
;; Conventions:

trobertson

module Data.Zipper where

data ZipperList a = ZL {
        prev :: [a]
      , next :: [a]
      }

-- it's an efficient list traversal, so we should be able to map over it
instance Functor ZipperList where
    fmap foo (ZL p n) = ZL (fmap foo p) (fmap foo n)

trobertson

-- adds up how many zeros are in the elements of a list
cz :: Show a => [a] -> Int
cz = sum . map length . map (filter (=='0')) . map show

-- the (.) means function composition, and lets you exclude the
-- variable being operated on. so:
-- f . g == f (g (x))

cz' :: Show a => [a] -> Int
cz' s = sum (map length (map (filter (=='0')) (map show s)))