Updating to prefer nilp() over '== nil'

src/lists.coffee

@@ -44,8 +44,8 @@ recordp = (c) -> Object.prototype.toString.call(c) == '[object Object]'
 nilp = (c) -> !!c.isList and c.length == 0
 
 cons = (a = nil, b = nil) ->
-  return nil if (nilp a) and (nilp b)
+  return (new ConsList()) if (nilp a) and (nilp b)
-  if (a) then ConsList(a, b) else ConsList(b)
+  if (a) then (new ConsList(a, b)) else (new ConsList(b))
 
 car = (c) -> c[0]
 cdr = (c) -> c[1]

src/reduce.coffee

@@ -1,6 +1,7 @@
 {car, cdr, cons, listp, pairp, nilp,
   nil, list, listToString} = require './lists'
 
+
 length = (lst, l = 0) ->
   return l if (nilp lst) 
   length (cdr lst), (l + 1)
@@ -20,6 +21,7 @@ reduce = (lst, iteratee, memo, context) ->
     null
   memo
 
+
 map = (lst, iteratee, context, count = 0) ->
   return nil if nilp lst
   product = iteratee.call(context, (car lst), count, lst)
@@ -27,6 +29,7 @@ map = (lst, iteratee, context, count = 0) ->
     map((cdr lst), iteratee, context, count + 1)
   cons product, rest
 
+
 rmap = (lst, iteratee, context, count = 0) ->
   ptr = lst
   ret = cons()
@@ -35,8 +38,10 @@ rmap = (lst, iteratee, context, count = 0) ->
     ptr = cdr ptr
   ret
 
+
 reverse = (lst) -> rmap lst, (i) -> i
 
+
 filter = (lst, iteratee, context) ->
   return nil if nilp lst
   if iteratee.call(context, (car lst), lst)
@@ -44,6 +49,7 @@ filter = (lst, iteratee, context) ->
   else
     filter (cdr lst), iteratee, context
 
+
 module.exports =
   length: length
   reduce: reduce