monadic stack attempt in coffee script

gistfile1.coffee

# GOAL - immutable objects
# to make these composable they need to both have the same signature...

compose = (f, g) -> (x) -> g(f(x))

c = (f, args...) ->
  if(f)
    compose(f, c.apply(this,args)) 
  else
    nil


nil = (x) -> x

unit = (stack)-> 
  val: null 
  stack: stack

bind = (operation) -> (monadicState) -> operation(monadicState.stack)

push = (val) -> (stack) -> 
  val: null
  stack:[val].concat(stack)

pop = ()-> (stack)-> 
  val:stack[0]
  stack: stack.slice(1)

b = (operation)-> (state)-> operation(state.stack)

call = (operation, stack) -> operation(unit(stack)).stack

output = (monadicFunction)->(state) ->
    result = monadicFunction(state)
    console.log("popped value was :" + result.val)
    result
    
r = (monadicFunction, observer) -> (state) ->
    result = monadicFunction(state)
    observer(result.val)
    result

v1=0
v2=0

pushnpop = c(
  b(push(4)),
  b(push(5)),
  r(b(pop()), (v) -> v1 = v)
  r(b(pop()), (v) -> v2 = v)  
);

console.log(call(pushnpop, []));
console.log(v1 + ","+ v2);