From f104b5e512ea0e6fe968a635771677f8622d8d0b Mon Sep 17 00:00:00 2001
From: Sander Spies <sandermail@gmail.com>
Date: Tue, 21 Jan 2020 21:23:31 +0100
Subject: [PATCH] Handle parentheses when destructuring.

---
 src/passes/1-parser/reasonligo/Parser.mly      |  2 +-
 src/passes/2-simplify/cameligo.ml              | 11 ++++++++---
 src/test/contracts/tuple_param_destruct.mligo  |  3 ++-
 src/test/contracts/tuple_param_destruct.religo |  3 ++-
 src/test/integration_tests.ml                  | 10 ++++++----
 5 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/passes/1-parser/reasonligo/Parser.mly b/src/passes/1-parser/reasonligo/Parser.mly
index c4ad40826..a6eea7961 100644
--- a/src/passes/1-parser/reasonligo/Parser.mly
+++ b/src/passes/1-parser/reasonligo/Parser.mly
@@ -430,7 +430,7 @@ fun_expr:
     | EUnit u -> PUnit u
     | ETuple { value; region } -> 
         PTuple { value = Utils.nsepseq_map arg_to_pattern value; region}
-    | EAnnot {region; value = {inside = ETuple _ as t, colon, typ; _}} -> 
+    | EAnnot {region; value = {inside = t, colon, typ; _}} -> 
         let value = { pattern = arg_to_pattern t; colon; type_expr = typ} in
         PPar {
           value = {
diff --git a/src/passes/2-simplify/cameligo.ml b/src/passes/2-simplify/cameligo.ml
index d4445c7bd..917d001bf 100644
--- a/src/passes/2-simplify/cameligo.ml
+++ b/src/passes/2-simplify/cameligo.ml
@@ -179,6 +179,10 @@ let rec tuple_pattern_to_typed_vars : Raw.pattern -> _ = fun pattern ->
   | Raw.PVar _ -> bind_list [pattern_to_typed_var pattern]
   | other -> (fail @@ wrong_pattern "parenthetical, tuple, or variable" other)
 
+let rec unpar_pattern : Raw.pattern -> Raw.pattern = function
+  | PPar p -> unpar_pattern p.value.inside
+  | _ as p -> p
+
 let rec simpl_type_expression : Raw.type_expr -> type_expression result = fun te ->
   trace (simple_info "simplifying this type expression...") @@
   match te with
@@ -541,7 +545,8 @@ and simpl_fun lamb' : expr result =
         (match pt with
         | Raw.PTyped pt ->
           begin
-          match pt.value.pattern with
+          let pt_pattern = unpar_pattern pt.value.pattern in
+          match pt_pattern with
           | Raw.PVar _ -> params
           | Raw.PTuple _ ->
             [Raw.PTyped
@@ -581,10 +586,10 @@ and simpl_fun lamb' : expr result =
     match destruct with (* Handle tuple parameter destructuring *)
     (* In this section we create a let ... in that binds the original parameters *)
     | Raw.PPar pp ->
-      (match pp.value.inside with
+      (match unpar_pattern pp.value.inside with
        | Raw.PTyped pt ->
          let vars = pt.value in
-         (match vars.pattern with
+         (match unpar_pattern vars.pattern with
           | PTuple vars ->
             let let_in_binding: Raw.let_binding =
               {binders = (PTuple vars, []) ;
diff --git a/src/test/contracts/tuple_param_destruct.mligo b/src/test/contracts/tuple_param_destruct.mligo
index 6dfe30fe4..d9cfc6513 100644
--- a/src/test/contracts/tuple_param_destruct.mligo
+++ b/src/test/contracts/tuple_param_destruct.mligo
@@ -1 +1,2 @@
-let sum (result, i : int * int) : int = result + i
+let sum (result, i : int * int) : int = result - i
+let parentheses ((((result, i))) : ((int * int))) : int = result - i
diff --git a/src/test/contracts/tuple_param_destruct.religo b/src/test/contracts/tuple_param_destruct.religo
index 389bf9835..3641ab8d0 100644
--- a/src/test/contracts/tuple_param_destruct.religo
+++ b/src/test/contracts/tuple_param_destruct.religo
@@ -1 +1,2 @@
-let sum = ((result, i) : (int, int)) : int => result + i;
+let sum = ((result, i) : (int, int)) : int => result - i;
+let parentheses = (((((result, i)))) : (((int, int)))) : int => result - i;
diff --git a/src/test/integration_tests.ml b/src/test/integration_tests.ml
index 0f9ebfb8f..6abe31226 100644
--- a/src/test/integration_tests.ml
+++ b/src/test/integration_tests.ml
@@ -1943,13 +1943,15 @@ let type_tuple_destruct () : unit result =
 
 let tuple_param_destruct () : unit result =
   let%bind program = mtype_file "./contracts/tuple_param_destruct.mligo" in
-  let%bind () = expect_eq program "sum" (e_tuple [e_int 10; e_int 10]) (e_int 20)
-  in ok ()
+  let%bind () = expect_eq program "sum" (e_tuple [e_int 20; e_int 10]) (e_int 10) in
+  let%bind () = expect_eq program "parentheses" (e_tuple [e_int 20; e_int 10]) (e_int 10) in
+  ok ()
 
 let tuple_param_destruct_religo () : unit result =
   let%bind program = retype_file "./contracts/tuple_param_destruct.religo" in
-  let%bind () = expect_eq program "sum" (e_tuple [e_int 10; e_int 10]) (e_int 20)
-  in ok ()
+  let%bind () = expect_eq program "sum" (e_tuple [e_int 20; e_int 10]) (e_int 10) in
+  let%bind () = expect_eq program "parentheses" (e_tuple [e_int 20; e_int 10]) (e_int 10) in
+  ok ()
 
 let let_in_multi_bind () : unit result =
   let%bind program = mtype_file "./contracts/let_in_multi_bind.mligo" in