Merge pull request #1061 from chenglou/from_opt

Implement from_opt for Js_null, js_undefined, js_null_undefined

Author: bobzhang

jscomp/others/.depend

@@ -15,6 +15,7 @@ bs_dyn.cmj : bs_dyn.cmi
 bs_dyn_lib.cmj : bs_dyn.cmj bs_dyn_lib.cmi
 node_child_process.cmj :
 js_boolean.cmj : js_boolean.cmi
+js_math.cmj :
 js_re.cmi :
 js_null_undefined.cmi :
 js_types.cmi :

jscomp/others/js_null_undefined.ml

@@ -1,5 +1,5 @@
 (* Copyright (C) 2015-2016 Bloomberg Finance L.P.
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
@@ -17,7 +17,7 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
@@ -32,8 +32,13 @@ let bind x f =
   match to_opt x with
   | None -> empty
   | Some x -> return (f  x [@bs])
-    
+
 let iter x f =
-  match to_opt  x with 
+  match to_opt  x with
   | None -> ()
   | Some x -> f x [@bs]
+
+let from_opt x =
+  match x with
+  | None -> empty
+  | Some x -> return x

jscomp/runtime/js_null.ml

@@ -29,11 +29,18 @@ external return : 'a -> 'a t  = "%identity"
 external test : 'a t -> bool = "js_is_nil"
 external empty : 'a t = "null" [@@bs.val]
 (*end::interface_all[]*)
+
 let bind x f =
-  match to_opt x with 
-  | None -> empty 
+  match to_opt x with
+  | None -> empty
   | Some x -> return (f x [@bs])
+
 let iter x f =
   match to_opt x with
-  | None ->  () 
+  | None ->  ()
   | Some x -> f x [@bs]
+
+let from_opt x =
+  match x with
+  | None -> empty
+  | Some x -> return x

jscomp/runtime/js_undefined.ml

@@ -1,5 +1,5 @@
 (* Copyright (C) 2015-2016 Bloomberg Finance L.P.
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
@@ -17,17 +17,17 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
 
 
-type + 'a t = 'a Js.undefined 
+type + 'a t = 'a Js.undefined
 external to_opt : 'a t -> 'a option = "js_from_def"
 external return : 'a -> 'a t = "%identity"
 external test : 'a t -> bool =  "js_is_undef"
-external empty : 'a t = "undefined" 
+external empty : 'a t = "undefined"
 [@@bs.val]
 
 let bind x f =
@@ -37,5 +37,10 @@ let bind x f =
 
 let iter x f =
   match to_opt x with
-  | None ->  () 
+  | None ->  ()
   | Some x -> f x [@bs]
+
+let from_opt x =
+  match x with
+  | None -> empty
+  | Some x -> return x