A tiny working compilation!

Author: finnhodgkin

.gitignore

@@ -18,3 +18,4 @@ Thumbs.db
 # Test files
 /test.purs
 *.purs.bak
+/output

src/codegen/js.rs

@@ -237,6 +237,7 @@ codegen_test_multi!(codegen_operator_module_reexport, "OperatorModuleReexport",
 codegen_test_multi!(codegen_superclass_dict, "SuperclassDict", "TestSuperclass.purs", ["MyFunctor.purs", "MyApply.purs", "TestSuperclass.purs"]);
 codegen_test!(codegen_call_site_dict_passing, "CallSiteDictPassing");
 codegen_test_multi!(codegen_superclass_dict_deep, "SuperclassDictDeep", "TestDeep.purs", ["MyFunctor.purs", "MyApply.purs", "MyAlternative.purs", "MyPrelude.purs", "TestDeep.purs"]);
+codegen_test_multi!(codegen_method_constraints, "MethodConstraints", "MyEq1.purs", ["MyEq.purs", "MyEq1.purs", "TestMethodConstraints.purs"]);
 
 // ===== Node.js execution tests =====
 // These tests verify that the generated JS actually runs correctly by executing

src/typechecker/check.rs

@@ -0,0 +1,10 @@
+module MyEq where
+
+class MyEq a where
+  myEq :: a -> a -> Boolean
+
+instance myEqInt :: MyEq Int where
+  myEq x y = true
+
+instance myEqArray :: MyEq a => MyEq (Array a) where
+  myEq xs ys = true

src/typechecker/infer.rs

@@ -0,0 +1,9 @@
+module MyEq1 where
+
+import MyEq (class MyEq, myEq)
+
+class MyEq1 f where
+  myEq1 :: forall a. MyEq a => f a -> f a -> Boolean
+
+instance myEq1Array :: MyEq1 Array where
+  myEq1 = myEq

tests/codegen.rs

@@ -0,0 +1,8 @@
+module TestMethodConstraints where
+
+import MyEq (class MyEq)
+import MyEq1 (class MyEq1, myEq1)
+
+-- Use eq1 in a constrained function to verify dict passing works
+testEq1 :: forall a. MyEq a => Array a -> Array a -> Boolean
+testEq1 xs ys = myEq1 xs ys

tests/fixtures/codegen/MethodConstraints/MyEq.purs

@@ -14,5 +14,9 @@ var wrapper = function(dictMyShow) {
   };
 };
 
+var myShow = function(dict) {
+  return dict.myShow;
+};
+
 
-export { myShowThing, wrapper };
+export { myShow, myShowThing, wrapper };

tests/fixtures/codegen/MethodConstraints/MyEq1.purs

@@ -18,6 +18,14 @@ var describeTwo = function(dictDescribable) {
   };
 };
 
+var describe = function(dict) {
+  return dict.describe;
+};
+
+var myEq = function(dict) {
+  return dict.myEq;
+};
+
 var describableBool = {
   describe: function($arg0_1) {
     if ($arg0_1 === true) {
@@ -45,4 +53,4 @@ var myEqInt = {
 };
 
 
-export { describableBool, describableInt, describeTwo, myEqInt, showDesc };
+export { describableBool, describableInt, describe, describeTwo, myEq, myEqInt, showDesc };