Merge pull request #1893 from glennsl/vector-append

Add Js.Vector.append

Author: bobzhang

jscomp/others/js_vector.ml

@@ -136,4 +136,7 @@ let mapi f a =
     r
   end
 
+let append x a =
+  Js.Array.concat [|x|] a
+
 (* TODO: add [append] *)  

jscomp/others/js_vector.mli

@@ -85,12 +85,8 @@ val init : int -> (int -> 'a [@bs]) -> 'a t
     @param fn callback
     @raise RangeError when [n] is negative  *)
 
-(*val append : 'a t -> 'a t -> 'a t *)
-(** create a new array, there is no shallow-sharing
-    between the output and input
-*)
+val append : 'a -> 'a t -> 'a t
+(** [append x a] returns a fresh array with x appended to a *)
 
 external unsafe_get : 'a t -> int -> 'a = "%array_unsafe_get"
 external unsafe_set : 'a t -> int -> 'a -> unit = "%array_unsafe_set"
-
-

lib/js/js_vector.js

@@ -143,6 +143,10 @@ function mapi(f, a) {
   }
 }
 
+function append(x, a) {
+  return a.concat(/* array */[x]);
+}
+
 exports.filterInPlace = filterInPlace;
 exports.empty         = empty;
 exports.pushBack      = pushBack;
@@ -157,4 +161,5 @@ exports.mapi          = mapi;
 exports.foldLeft      = foldLeft;
 exports.foldRight     = foldRight;
 exports.init          = init;
+exports.append        = append;
 /* No side effect */