Merge pull request #652 from hellerve/veit/const

Add const

core/Generics.carp

@@ -74,6 +74,7 @@ The margin of error is 0.00001.")
   (not (neg? x)))
 
 (defn id [x] x)
+(defn const [x] (fn [_] x))
 
 (defn null? [p]
   (Pointer.eq NULL (the (Ptr t) p)))
@@ -106,4 +107,4 @@ The margin of error is 0.00001.")
 (defn /= [a b]
   (not (= a b)))
 
-)
+)

test/generics.carp

@@ -0,0 +1,21 @@
+(load "Test.carp")
+
+(use Test)
+
+(deftest test
+  (assert-equal test
+                1
+                (id 1)
+                "id works I"
+  )
+  (assert-equal test
+                &(Maybe.Just 1)
+                &(id (Maybe.Just 1))
+                "id works II"
+  )
+  (assert-equal test
+                20
+                ((const 20) 1)
+                "const works"
+  )
+)