Kata

Let's see 2 ways of applying successive functions to an object:

The purpose of this kata is to think of this kind of code

var result = fn4(fn3(fn2(fn1(obj))));

in terms of pipelining or composition of functions.

1. Pipelining

   var result = pipeline(obj
                         , fn1
                         , fn2
                         , fn3
                         , fn4);
   

for instance:

pipeline([1,2,3,4,5,6] // seed
    , rest // first function to apply
    , rest // second function to apply
    , rest // ..
    , rest
    , first);
=> 5

2. Composition: it should return a function that is the composition of a list of functions, where each function consumes the return value of the function that follows.

   var compositionFn = compose(fn4, fn3, fn2, fn1);
   var result = compositionFn(obj);
   

   for instance

   var greet    = function(name){ return "hi: " + name; };
   var exclaim  = function(statement){ return statement.toUpperCase() + "!"; };
   var welcome = compose(greet, exclaim);
   welcome('moe');
   => 'hi: MOE!'