Don't transcode function values when the type is an EmptyDataDecl (closes #354)

Author: bergmark

js/runtime.js

@@ -237,13 +237,13 @@ function Fay$$fayToJs(type,fayObj){
   }
   else if(base == "ptr" || base == "unknown")
     return fayObj;
+  else if(base == "automatic" && fayObj instanceof Function) {
+    return Fay$$fayToJs(["function", "automatic_function"], fayObj);
+  }
   else if(base == "automatic" || base == "user") {
-
     fayObj = Fay$$_(fayObj);
 
-    if(fayObj instanceof Function) {
-      return Fay$$fayToJs(["function", "automatic_function"], fayObj);
-    } else if(fayObj instanceof Fay$$Cons || fayObj === null){
+    if(fayObj instanceof Fay$$Cons || fayObj === null){
       // Serialize Fay list to JavaScript array.
       var arr = [];
       while(fayObj instanceof Fay$$Cons) {
@@ -388,6 +388,12 @@ function Fay$$jsToFay(type,jsObj){
            base ==  "unknown") {
     return jsObj;
   }
+  else if(base == "automatic" && jsObj instanceof Function) {
+    var type = [["automatic"]];
+    for (var i = 0; i < jsObj.length; i++)
+      type.push(["automatic"]);
+    return Fay$$jsToFay(["function", type], jsObj);
+  }
   else if(base == "automatic" || base == "user") {
     if (jsObj && jsObj['instance']) {
       var jsToFayFun = Fay$$jsToFayHash[jsObj["instance"]];
@@ -400,12 +406,6 @@ function Fay$$jsToFay(type,jsObj){
       }
       return list;
     }
-    else if (jsObj instanceof Function) {
-      var type = [["automatic"]];
-      for (var i = 0; i < jsObj.length; i++)
-        type.push(["automatic"]);
-      return Fay$$jsToFay(["function", type], jsObj);
-    }
     else
       return jsObj;
   }

tests/JsFunctionPassing.hs

@@ -0,0 +1,22 @@
+{-# LANGUAGE EmptyDataDecls #-}
+
+import           FFI
+import           Prelude
+
+data Func
+
+makeFunc0 :: Int -> Func
+makeFunc0 = ffi "function() {return %1;}"
+
+callFunc0 :: Func -> Fay Int
+callFunc0 = ffi "%1()"
+
+makeFunc1 :: Int -> Func
+makeFunc1 = ffi "function(x) {return %1;}"
+
+callFunc1 :: Func -> Fay Int
+callFunc1 = ffi "%1(1)"
+
+main = do
+  callFunc0 (makeFunc0 1) >>= print
+  callFunc1 (makeFunc1 2) >>= print

tests/JsFunctionPassing.res

@@ -0,0 +1,2 @@
+1
+2