Add anaphoric if statement

hy/contrib/anaphoric.hy

@@ -1,6 +1,7 @@
 ;;; Hy anaphoric macros
 ;;
 ;; Copyright (c) 2013 James King <james@agentultra.com>
+;;               2013 Paul R. Tagliamonte <tag@pault.ag>
 ;;
 ;; Permission is hereby granted, free of charge, to any person obtaining a
 ;; copy of this software and associated documentation files (the "Software"),
@@ -23,6 +24,10 @@
 ;;; These macros make writing functional programs more concise
 
 
+(defmacro ap-if (test-form &rest args)
+  `(let [[it ~test-form]] (if it ~@args)))
+
+
 (defmacro ap-each [lst &rest body]
   "Evaluate the body form for each element in the list."
   `(foreach [it ~lst] ~@body))

tests/native_tests/contrib/anaphoric.hy

@@ -31,6 +31,12 @@
 (defn assert-equal [x y]
   (assert (= x y)))
 
+
+(defn test-ap-if []
+  "NATIVE: testing anaphoric if"
+  (ap-if true (assert-true it))
+  (ap-if false true (assert-false it)))
+
 (defn test-ap-each []
   "NATIVE: testing anaphoric each"
   (setv res [])