Merge pull request #782 from acron0/last-core

Added (last) function to core language

AUTHORS

@@ -61,3 +61,4 @@
 * Shenyang Zhao <dev@zsy.im>
 * Zack M. Davis <code@zackmdavis.net>
 * Adrià Garriga Alonso <adria@monkingme.com>
+* Antony Woods <antony@teamwoods.org>

docs/language/api.rst

@@ -945,6 +945,18 @@ This can be confirmed via Python's built-in ``help`` function::
     Multiplies input by three and returns result
     (END)
 	
+last
+-----------
+
+.. versionadded:: 0.10.2
+
+``last`` can be used for accessing the last element of a collection:
+
+.. code-block:: clj
+
+    => (last [2 4 6])
+    6
+	
 
 let
 ---

hy/core/language.hy

@@ -243,6 +243,10 @@
   "Return true if x is an iterator"
   (isinstance x collections.Iterator))
 
+(defn last [coll]
+  "Return last item from `coll`"
+  (get (list coll) -1))
+
 (defn list* [hd &rest tl]
   "Return a dotted list construed from the elements of the argument"
   (if (not tl)
@@ -416,7 +420,7 @@
                  dec distinct disassemble drop drop-last drop-while empty? even?
                  every? first filter filterfalse flatten float? gensym identity
                  inc input instance? integer integer? integer-char? interleave
-                 interpose iterable? iterate iterator? keyword keyword? list*
+                 interpose iterable? iterate iterator? keyword keyword? last list*
                  macroexpand macroexpand-1 map merge-with name neg? nil? none?
                  nth numeric? odd? pos? range read remove repeat repeatedly
                  rest reduce second some string string? symbol? take take-nth

tests/native_tests/core.hy

@@ -382,6 +382,13 @@
   ;; should not work for an int
   (assert-false (iterator? 5)))
 
+(defn test-last []
+  "NATIVE: testing the last function"
+  (assert-equal (last [1 2 3 4]) 4)
+  (assert-equal (last [5]) 5))
+  (import itertools)
+  (assert-equal (last (take 5 (itertools.count 10))) 14)
+
 (defn test-neg []
   "NATIVE: testing the neg? function"
   (assert-true (neg? -2))