[feat] Added length count to utilities.

src/reduce.coffee

@@ -1,6 +1,11 @@
 {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)
+  
+
 reduce = (lst, iteratee, memo, context) ->
   count = 0
   console.log lst
@@ -40,6 +45,7 @@ filter = (lst, iteratee, context) ->
     filter (cdr lst), iteratee, context
 
 module.exports =
+  length: length
   reduce: reduce
   map: map
   rmap: rmap

test/reduce.coffee

@@ -4,10 +4,26 @@ expect = chai.expect
 
 {listToVector, vectorToList,
   listToString, cons, list, nil} = require '../src/lists'
-{map, reduce, filter, reverse} = require '../src/reduce'
+{map, reduce, filter, reverse, length} = require '../src/reduce'
 
 id = (item) -> item
 
+describe 'Length Testing', ->
+  
+  samples = [
+    [cons(), 0]
+    [cons(nil), 0]
+    [cons('a'), 1]
+    [cons('a', cons('b')), 2]
+    [cons('a', cons('b', cons('c'))), 3]
+    [cons('a', cons('b', cons('c'), nil)), 3]]
+
+  for [t, v] in samples
+    do (t, v) ->
+      it "should produce a length of  #{v}", ->
+        product = length(t)
+        expect(product).to.equal(v)
+
 describe 'Map Identity Testing', ->
 
   samples = [