From 2c62f9d32e5e4db15ae9c9dc3b78ab4a4179d439 Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Wulfman <pierre.emmanuel.wulfman@gmail.com>
Date: Thu, 23 Apr 2020 17:28:05 +0200
Subject: [PATCH 1/2] remove match_bool from the ast

---
 src/passes/10-interpreter/interpreter.ml      |  7 +++---
 src/passes/10-transpiler/transpiler.ml        | 12 +++++-----
 .../2-concrete_to_imperative/cameligo.ml      |  2 +-
 .../2-concrete_to_imperative/pascaligo.ml     |  2 +-
 src/passes/3-self_ast_imperative/helpers.ml   | 15 ------------
 .../imperative_to_sugar.ml                    | 24 -------------------
 src/passes/5-self_ast_sugar/helpers.ml        | 15 ------------
 src/passes/6-sugar_to_core/sugar_to_core.ml   | 10 +-------
 src/passes/7-self_ast_core/helpers.ml         | 15 ------------
 src/passes/8-typer-new/typer.ml               |  8 -------
 src/passes/8-typer-new/untyper.ml             |  4 ----
 src/passes/8-typer-old/typer.ml               | 12 ----------
 src/passes/9-self_ast_typed/helpers.ml        | 15 ------------
 src/passes/9-self_ast_typed/tail_recursion.ml |  4 ----
 src/stages/1-ast_imperative/PP.ml             |  4 ----
 src/stages/2-ast_sugar/PP.ml                  |  4 ----
 src/stages/3-ast_core/PP.ml                   |  4 ----
 src/stages/4-ast_typed/PP.ml                  |  2 --
 src/stages/4-ast_typed/misc.ml                |  1 -
 src/stages/4-ast_typed/misc_smart.ml          |  4 ----
 src/stages/4-ast_typed/types.ml               |  5 ----
 src/stages/common/types.ml                    |  4 ----
 22 files changed, 12 insertions(+), 161 deletions(-)

diff --git a/src/passes/10-interpreter/interpreter.ml b/src/passes/10-interpreter/interpreter.ml
index 601381bc8..949a832b1 100644
--- a/src/passes/10-interpreter/interpreter.ml
+++ b/src/passes/10-interpreter/interpreter.ml
@@ -342,6 +342,9 @@ and eval : Ast_typed.expression -> env -> value result
         let {hd;tl;body;tv=_} = cases.match_cons in
         let env' = Env.extend (Env.extend env (hd,head)) (tl, V_List tail) in
         eval body env'
+      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false"; body=match_false}];_}, V_Ct (C_bool b) ->
+        if b then eval match_true env
+        else eval match_false env
       | Match_variant {cases ; tv=_} , V_Construct (matched_c , proj) ->
         let {constructor=_ ; pattern ; body} =
           List.find
@@ -350,10 +353,6 @@ and eval : Ast_typed.expression -> env -> value result
             cases in
         let env' = Env.extend env (pattern, proj) in
         eval body env'
-      | Match_bool cases , V_Ct (C_bool true) ->
-        eval cases.match_true env
-      | Match_bool cases , V_Ct (C_bool false) ->
-        eval cases.match_false env
       | Match_option cases, V_Construct ("Some" , proj) ->
         let {opt;body;tv=_} = cases.match_some in
         let env' = Env.extend env (opt,proj) in
diff --git a/src/passes/10-transpiler/transpiler.ml b/src/passes/10-transpiler/transpiler.ml
index ed78a683d..4bf78a0c9 100644
--- a/src/passes/10-transpiler/transpiler.ml
+++ b/src/passes/10-transpiler/transpiler.ml
@@ -560,9 +560,6 @@ and transpile_annotated_expression (ae:AST.expression) : expression result =
   | E_matching {matchee=expr; cases=m} -> (
       let%bind expr' = transpile_annotated_expression expr in
       match m with
-      | Match_bool {match_true ; match_false} ->
-          let%bind (t , f) = bind_map_pair (transpile_annotated_expression) (match_true, match_false) in
-          return @@ E_if_bool (expr', t, f)
       | Match_option { match_none; match_some = {opt; body; tv} } ->
           let%bind n = transpile_annotated_expression match_none in
           let%bind (tv' , s') =
@@ -583,6 +580,9 @@ and transpile_annotated_expression (ae:AST.expression) : expression result =
           in
           return @@ E_if_cons (expr' , nil , cons)
         )
+      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false";body=match_false}];_} ->
+          let%bind (t , f) = bind_map_pair (transpile_annotated_expression) (match_true, match_false) in
+          return @@ E_if_bool (expr', t, f)
       | Match_variant {cases ; tv} -> (
           let%bind tree =
             trace_strong (corner_case ~loc:__LOC__ "getting lr tree") @@
@@ -683,9 +683,6 @@ and transpile_recursive {fun_name; fun_type; lambda} =
     let return ret = ok @@ Expression.make ret @@ ty in
     let%bind expr = transpile_annotated_expression m.matchee in
     match m.cases with
-      Match_bool {match_true; match_false} -> 
-          let%bind (t , f) = bind_map_pair (replace_callback fun_name loop_type shadowed) (match_true, match_false) in
-          return @@ E_if_bool (expr, t, f)
       | Match_option { match_none; match_some = {opt; body; tv} } ->
           let%bind n = replace_callback fun_name loop_type shadowed match_none in
           let%bind (tv' , s') =
@@ -706,6 +703,9 @@ and transpile_recursive {fun_name; fun_type; lambda} =
           in
           return @@ E_if_cons (expr , nil , cons)
         )
+      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false";body=match_false}];_} ->
+          let%bind (t , f) = bind_map_pair (replace_callback fun_name loop_type shadowed) (match_true, match_false) in
+          return @@ E_if_bool (expr, t, f)
       | Match_variant {cases;tv} -> (
           let%bind tree =
             trace_strong (corner_case ~loc:__LOC__ "getting lr tree") @@
diff --git a/src/passes/2-concrete_to_imperative/cameligo.ml b/src/passes/2-concrete_to_imperative/cameligo.ml
index c70bdf106..33d8cca21 100644
--- a/src/passes/2-concrete_to_imperative/cameligo.ml
+++ b/src/passes/2-concrete_to_imperative/cameligo.ml
@@ -1026,7 +1026,7 @@ and compile_cases : type a . (Raw.pattern * a) list -> (a, unit) matching_conten
   match patterns with
   | [(PFalse _, f) ; (PTrue _, t)]
   | [(PTrue _, t) ; (PFalse _, f)] ->
-      ok @@ Match_bool {match_true = t ; match_false = f}
+      ok @@ Match_variant ([((Constructor "true", Var.of_name "_"), t); ((Constructor "false", Var.of_name "_"), f)], ())
   | [(PList (PCons c), cons); (PList (PListComp sugar_nil), nil)]
   | [(PList (PListComp sugar_nil), nil); (PList (PCons c), cons)] ->
       let%bind () =
diff --git a/src/passes/2-concrete_to_imperative/pascaligo.ml b/src/passes/2-concrete_to_imperative/pascaligo.ml
index 95e17d299..4ebef1559 100644
--- a/src/passes/2-concrete_to_imperative/pascaligo.ml
+++ b/src/passes/2-concrete_to_imperative/pascaligo.ml
@@ -1056,7 +1056,7 @@ and compile_cases : (Raw.pattern * expression) list -> matching_expr result = fu
   match patterns with
   | [(PConstr PFalse _ , f) ; (PConstr PTrue _ , t)]
   | [(PConstr PTrue _ , t) ; (PConstr PFalse _ , f)] ->
-      ok @@ Match_bool {match_true = t ; match_false = f}
+      ok @@ Match_variant ([((Constructor "true", Var.of_name "_"), t); ((Constructor "false", Var.of_name "_"), f)], ())
   | [(PConstr PSomeApp v , some) ; (PConstr PNone _ , none)]
   | [(PConstr PNone _ , none) ; (PConstr PSomeApp v , some)] -> (
       let (_, v) = v.value in
diff --git a/src/passes/3-self_ast_imperative/helpers.ml b/src/passes/3-self_ast_imperative/helpers.ml
index 677789b6f..159aa7bfb 100644
--- a/src/passes/3-self_ast_imperative/helpers.ml
+++ b/src/passes/3-self_ast_imperative/helpers.ml
@@ -104,11 +104,6 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
 
 and fold_cases : 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind res = fold_expression f init match_true in
-      let%bind res = fold_expression f res match_false in
-      ok res
-    )
   | Match_list { match_nil ; match_cons = (_ , _ , cons, _) } -> (
       let%bind res = fold_expression f init match_nil in
       let%bind res = fold_expression f res cons in
@@ -272,11 +267,6 @@ and map_type_expression : ty_exp_mapper -> type_expression -> type_expression re
 
 and map_cases : exp_mapper -> matching_expr -> matching_expr result = fun f m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind match_true = map_expression f match_true in
-      let%bind match_false = map_expression f match_false in
-      ok @@ Match_bool { match_true ; match_false }
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind match_nil = map_expression f match_nil in
       let%bind cons = map_expression f cons in
@@ -433,11 +423,6 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
 
 and fold_map_cases : 'a fold_mapper -> 'a -> matching_expr -> ('a * matching_expr) result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind (init, match_true) = fold_map_expression f init match_true in
-      let%bind (init, match_false) = fold_map_expression f init match_false in
-      ok @@ (init, Match_bool { match_true ; match_false })
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind (init, match_nil) = fold_map_expression f init match_nil in
       let%bind (init, cons) = fold_map_expression f init cons in
diff --git a/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml b/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
index e5742ac5b..bdaf7f495 100644
--- a/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
+++ b/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
@@ -381,26 +381,6 @@ and compile_matching : I.matching -> (O.expression option -> O.expression) resul
   in
   let%bind matchee = compile_expression matchee in
   match cases with 
-    | I.Match_bool {match_true;match_false} ->
-      let%bind match_true' = compile_expression match_true in
-      let%bind match_false' = compile_expression match_false in
-      let env = Var.fresh () in
-      let%bind ((_,free_vars_true), match_true) = repair_mutable_variable_in_matching match_true' [] env in
-      let%bind ((_,free_vars_false), match_false) = repair_mutable_variable_in_matching match_false' [] env in
-      let match_true  = add_to_end match_true (O.e_variable env) in
-      let match_false = add_to_end match_false (O.e_variable env) in
-
-      let free_vars = List.sort_uniq Var.compare @@ free_vars_true @ free_vars_false in
-      if (List.length free_vars != 0) then 
-        let match_expr  = O.e_matching matchee (O.Match_bool {match_true; match_false}) in
-        let return_expr = fun expr ->
-          O.e_let_in (env,None) false false (store_mutable_variable free_vars) @@
-          O.e_let_in (env,None) false false match_expr @@
-          expr 
-        in
-        ok @@ restore_mutable_variable return_expr free_vars env
-      else
-        return @@ O.e_matching matchee @@ O.Match_bool {match_true=match_true';match_false=match_false'}
     | I.Match_option {match_none;match_some} ->
       let%bind match_none' = compile_expression match_none in
       let (n,expr,tv) = match_some in
@@ -765,10 +745,6 @@ and uncompile_lambda : O.lambda -> I.lambda result =
 and uncompile_matching : O.matching_expr -> I.matching_expr result =
   fun m -> 
   match m with 
-    | O.Match_bool {match_true;match_false} ->
-      let%bind match_true = uncompile_expression' match_true in
-      let%bind match_false = uncompile_expression' match_false in
-      ok @@ I.Match_bool {match_true;match_false}
     | O.Match_list {match_nil;match_cons} ->
       let%bind match_nil = uncompile_expression' match_nil in
       let (hd,tl,expr,tv) = match_cons in
diff --git a/src/passes/5-self_ast_sugar/helpers.ml b/src/passes/5-self_ast_sugar/helpers.ml
index 0d3b353b7..953a8910f 100644
--- a/src/passes/5-self_ast_sugar/helpers.ml
+++ b/src/passes/5-self_ast_sugar/helpers.ml
@@ -103,11 +103,6 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
 
 and fold_cases : 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind res = fold_expression f init match_true in
-      let%bind res = fold_expression f res match_false in
-      ok res
-    )
   | Match_list { match_nil ; match_cons = (_ , _ , cons, _) } -> (
       let%bind res = fold_expression f init match_nil in
       let%bind res = fold_expression f res cons in
@@ -255,11 +250,6 @@ and map_type_expression : ty_exp_mapper -> type_expression -> type_expression re
 
 and map_cases : exp_mapper -> matching_expr -> matching_expr result = fun f m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind match_true = map_expression f match_true in
-      let%bind match_false = map_expression f match_false in
-      ok @@ Match_bool { match_true ; match_false }
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind match_nil = map_expression f match_nil in
       let%bind cons = map_expression f cons in
@@ -402,11 +392,6 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
 
 and fold_map_cases : 'a fold_mapper -> 'a -> matching_expr -> ('a * matching_expr) result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind (init, match_true) = fold_map_expression f init match_true in
-      let%bind (init, match_false) = fold_map_expression f init match_false in
-      ok @@ (init, Match_bool { match_true ; match_false })
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind (init, match_nil) = fold_map_expression f init match_nil in
       let%bind (init, cons) = fold_map_expression f init cons in
diff --git a/src/passes/6-sugar_to_core/sugar_to_core.ml b/src/passes/6-sugar_to_core/sugar_to_core.ml
index b0b91cd98..c10098f45 100644
--- a/src/passes/6-sugar_to_core/sugar_to_core.ml
+++ b/src/passes/6-sugar_to_core/sugar_to_core.ml
@@ -159,7 +159,7 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind matchee = compile_expression condition in
       let%bind match_true = compile_expression then_clause in
       let%bind match_false = compile_expression else_clause in
-      return @@ O.E_matching {matchee; cases=Match_bool{match_true;match_false}}
+      return @@ O.E_matching {matchee; cases=Match_variant ([((Constructor "true", Var.of_name "_"),match_true);((Constructor "false", Var.of_name "_"), match_false)],())}
     | I.E_sequence {expr1; expr2} ->
       let%bind expr1 = compile_expression expr1 in
       let%bind expr2 = compile_expression expr2 in
@@ -191,10 +191,6 @@ and compile_lambda : I.lambda -> O.lambda result =
 and compile_matching : I.matching_expr -> O.matching_expr result =
   fun m -> 
   match m with 
-    | I.Match_bool {match_true;match_false} ->
-      let%bind match_true = compile_expression match_true in
-      let%bind match_false = compile_expression match_false in
-      ok @@ O.Match_bool {match_true;match_false}
     | I.Match_list {match_nil;match_cons} ->
       let%bind match_nil = compile_expression match_nil in
       let (hd,tl,expr,tv) = match_cons in
@@ -360,10 +356,6 @@ and uncompile_lambda : O.lambda -> I.lambda result =
 and uncompile_matching : O.matching_expr -> I.matching_expr result =
   fun m -> 
   match m with 
-    | O.Match_bool {match_true;match_false} ->
-      let%bind match_true = uncompile_expression match_true in
-      let%bind match_false = uncompile_expression match_false in
-      ok @@ I.Match_bool {match_true;match_false}
     | O.Match_list {match_nil;match_cons} ->
       let%bind match_nil = uncompile_expression match_nil in
       let (hd,tl,expr,tv) = match_cons in
diff --git a/src/passes/7-self_ast_core/helpers.ml b/src/passes/7-self_ast_core/helpers.ml
index e76e4f064..d4311211e 100644
--- a/src/passes/7-self_ast_core/helpers.ml
+++ b/src/passes/7-self_ast_core/helpers.ml
@@ -72,11 +72,6 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
 
 and fold_cases : 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind res = fold_expression f init match_true in
-      let%bind res = fold_expression f res match_false in
-      ok res
-    )
   | Match_list { match_nil ; match_cons = (_ , _ , cons, _) } -> (
       let%bind res = fold_expression f init match_nil in
       let%bind res = fold_expression f res cons in
@@ -179,11 +174,6 @@ and map_type_expression : ty_exp_mapper -> type_expression -> type_expression re
 
 and map_cases : exp_mapper -> matching_expr -> matching_expr result = fun f m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind match_true = map_expression f match_true in
-      let%bind match_false = map_expression f match_false in
-      ok @@ Match_bool { match_true ; match_false }
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind match_nil = map_expression f match_nil in
       let%bind cons = map_expression f cons in
@@ -284,11 +274,6 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
 
 and fold_map_cases : 'a fold_mapper -> 'a -> matching_expr -> ('a * matching_expr) result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind (init, match_true) = fold_map_expression f init match_true in
-      let%bind (init, match_false) = fold_map_expression f init match_false in
-      ok @@ (init, Match_bool { match_true ; match_false })
-    )
   | Match_list { match_nil ; match_cons = (hd , tl , cons, _) } -> (
       let%bind (init, match_nil) = fold_map_expression f init match_nil in
       let%bind (init, cons) = fold_map_expression f init cons in
diff --git a/src/passes/8-typer-new/typer.ml b/src/passes/8-typer-new/typer.ml
index 5f780f7de..e6c7955a7 100644
--- a/src/passes/8-typer-new/typer.ml
+++ b/src/passes/8-typer-new/typer.ml
@@ -34,13 +34,6 @@ let rec type_declaration env state : I.declaration -> (environment * O.typer_sta
 
 and type_match : environment -> O.typer_state -> O.type_expression -> I.matching_expr -> I.expression -> Location.t -> (O.matching_expr * O.typer_state) result =
   fun e state t i ae loc -> match i with
-    | Match_bool {match_true ; match_false} ->
-      let%bind _ =
-        trace_strong (match_error ~expected:i ~actual:t loc)
-        @@ get_t_bool t in
-      let%bind (match_true , state') = type_expression e state match_true in
-      let%bind (match_false , state'') = type_expression e state' match_false in
-      ok (O.Match_bool {match_true ; match_false} , state'')
     | Match_option {match_none ; match_some} ->
       let%bind tv =
         trace_strong (match_error ~expected:i ~actual:t loc)
@@ -361,7 +354,6 @@ and type_expression : environment -> O.typer_state -> ?tv_opt:O.type_expression
       let tvs =
         let aux (cur : O.matching_expr) =
           match cur with
-          | Match_bool { match_true ; match_false } -> [ match_true ; match_false ]
           | Match_list { match_nil ; match_cons = { hd=_ ; tl=_ ; body ; tv=_} } -> [ match_nil ; body ]
           | Match_option { match_none ; match_some = {opt=_; body; tv=_} } -> [ match_none ; body ]
           | Match_tuple { vars=_ ; body ; tvs=_ } -> [ body ]
diff --git a/src/passes/8-typer-new/untyper.ml b/src/passes/8-typer-new/untyper.ml
index eccd21fab..11b3ef3b9 100644
--- a/src/passes/8-typer-new/untyper.ml
+++ b/src/passes/8-typer-new/untyper.ml
@@ -295,10 +295,6 @@ and untype_lambda ty {binder; result} : I.lambda result =
 and untype_matching : (O.expression -> I.expression result) -> O.matching_expr -> I.matching_expr result = fun f m ->
   let open I in
   match m with
-  | Match_bool {match_true ; match_false} ->
-      let%bind match_true = f match_true in
-      let%bind match_false = f match_false in
-      ok @@ Match_bool {match_true ; match_false}
   | Match_tuple { vars ; body ; tvs=_ } ->
       let%bind b = f body in
       ok @@ I.Match_tuple ((vars, b),[])
diff --git a/src/passes/8-typer-old/typer.ml b/src/passes/8-typer-old/typer.ml
index 18786393e..67385c1d5 100644
--- a/src/passes/8-typer-old/typer.ml
+++ b/src/passes/8-typer-old/typer.ml
@@ -496,13 +496,6 @@ and type_declaration env (_placeholder_for_state_of_new_typer : O.typer_state) :
 
 and type_match : (environment -> I.expression -> O.expression result) -> environment -> O.type_expression -> I.matching_expr -> I.expression -> Location.t -> O.matching_expr result =
   fun f e t i ae loc -> match i with
-    | Match_bool {match_true ; match_false} ->
-      let%bind _ =
-        trace_strong (match_error ~expected:i ~actual:t loc)
-        @@ get_t_bool t in
-      let%bind match_true = f e match_true in
-      let%bind match_false = f e match_false in
-      ok (O.Match_bool {match_true ; match_false})
   | Match_option {match_none ; match_some} ->
       let%bind tv =
         trace_strong (match_error ~expected:i ~actual:t loc)
@@ -911,7 +904,6 @@ and type_expression' : environment -> ?tv_opt:O.type_expression -> I.expression
       let tvs =
         let aux (cur:O.matching_expr) =
           match cur with
-          | Match_bool { match_true ; match_false } -> [ match_true ; match_false ]
           | Match_list { match_nil ; match_cons = {hd=_ ; tl=_ ; body ; tv=_} } -> [ match_nil ; body ]
           | Match_option { match_none ; match_some = {opt=_ ; body ; tv=_ } } -> [ match_none ; body ]
           | Match_tuple {vars=_;body;tvs=_} -> [ body ]
@@ -1081,10 +1073,6 @@ let rec untype_expression (e:O.expression) : (I.expression) result =
 and untype_matching : (O.expression -> I.expression result) -> O.matching_expr -> I.matching_expr result = fun f m ->
   let open I in
   match m with
-  | Match_bool {match_true ; match_false} ->
-      let%bind match_true = f match_true in
-      let%bind match_false = f match_false in
-      ok @@ Match_bool {match_true ; match_false}
   | Match_tuple {vars; body;tvs=_} ->
       let%bind b = f body in
       ok @@ I.Match_tuple ((vars, b),[])
diff --git a/src/passes/9-self_ast_typed/helpers.ml b/src/passes/9-self_ast_typed/helpers.ml
index c487ece1b..f42d1ea37 100644
--- a/src/passes/9-self_ast_typed/helpers.ml
+++ b/src/passes/9-self_ast_typed/helpers.ml
@@ -53,11 +53,6 @@ let rec fold_expression : 'a . 'a folder -> 'a -> expression -> 'a result = fun
 
 and fold_cases : 'a . 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind res = fold_expression f init match_true in
-      let%bind res = fold_expression f res match_false in
-      ok res
-    )
   | Match_list { match_nil ; match_cons = {hd=_; tl=_ ; body; tv=_} } -> (
       let%bind res = fold_expression f init match_nil in
       let%bind res = fold_expression f res body in
@@ -135,11 +130,6 @@ let rec map_expression : mapper -> expression -> expression result = fun f e ->
 
 and map_cases : mapper -> matching_expr -> matching_expr result = fun f m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind match_true = map_expression f match_true in
-      let%bind match_false = map_expression f match_false in
-      ok @@ Match_bool { match_true ; match_false }
-    ) 
   | Match_list { match_nil ; match_cons = {hd ; tl ; body ; tv} } -> (
       let%bind match_nil = map_expression f match_nil in
       let%bind body = map_expression f body in
@@ -230,11 +220,6 @@ let rec fold_map_expression : 'a . 'a fold_mapper -> 'a -> expression -> ('a * e
 
 and fold_map_cases : 'a . 'a fold_mapper -> 'a -> matching_expr -> ('a * matching_expr) result = fun f init m ->
   match m with
-  | Match_bool { match_true ; match_false } -> (
-      let%bind (init, match_true) = fold_map_expression f init match_true in
-      let%bind (init, match_false) = fold_map_expression f init match_false in
-      ok @@ (init, Match_bool { match_true ; match_false })
-    )
   | Match_list { match_nil ; match_cons = { hd ; tl ; body ; tv } } -> (
       let%bind (init, match_nil) = fold_map_expression f init match_nil in
       let%bind (init, body) = fold_map_expression f init body in
diff --git a/src/passes/9-self_ast_typed/tail_recursion.ml b/src/passes/9-self_ast_typed/tail_recursion.ml
index 1d478b9df..ef4098c36 100644
--- a/src/passes/9-self_ast_typed/tail_recursion.ml
+++ b/src/passes/9-self_ast_typed/tail_recursion.ml
@@ -59,10 +59,6 @@ let rec check_recursive_call : expression_variable -> bool -> expression -> unit
 
 and check_recursive_call_in_matching = fun n final_path c ->
   match c with
-  | Match_bool {match_true;match_false} ->
-    let%bind _ = check_recursive_call n final_path match_true in
-    let%bind _ = check_recursive_call n final_path match_false in
-    ok ()
   | Match_list {match_nil;match_cons={hd=_;tl=_;body;tv=_}} ->
     let%bind _ = check_recursive_call n final_path match_nil in
     let%bind _ = check_recursive_call n final_path body in
diff --git a/src/stages/1-ast_imperative/PP.ml b/src/stages/1-ast_imperative/PP.ml
index 8115de660..c17860f9f 100644
--- a/src/stages/1-ast_imperative/PP.ml
+++ b/src/stages/1-ast_imperative/PP.ml
@@ -183,8 +183,6 @@ and matching : type a . (formatter -> a -> unit) -> formatter -> (a,unit) matchi
         fprintf ppf "let (%a) = %a" (list_sep_d expression_variable) lst f b
     | Match_variant (lst, _) ->
         fprintf ppf "%a" (list_sep (matching_variant_case f) (tag "@.")) lst
-    | Match_bool {match_true ; match_false} ->
-        fprintf ppf "| True -> %a @.| False -> %a" f match_true f match_false
     | Match_list {match_nil ; match_cons = (hd, tl, match_cons, _)} ->
         fprintf ppf "| Nil -> %a @.| %a :: %a -> %a" f match_nil expression_variable hd expression_variable tl f match_cons
     | Match_option {match_none ; match_some = (some, match_some, _)} ->
@@ -196,8 +194,6 @@ and matching_type ppf m = match m with
       fprintf ppf "tuple"
   | Match_variant (lst, _) ->
       fprintf ppf "variant %a" (list_sep matching_variant_case_type (tag "@.")) lst
-  | Match_bool _ ->
-      fprintf ppf "boolean"
   | Match_list _ ->
       fprintf ppf "list"
   | Match_option _ ->
diff --git a/src/stages/2-ast_sugar/PP.ml b/src/stages/2-ast_sugar/PP.ml
index 2c266f787..8d8dad34b 100644
--- a/src/stages/2-ast_sugar/PP.ml
+++ b/src/stages/2-ast_sugar/PP.ml
@@ -150,8 +150,6 @@ and matching : type a . (formatter -> a -> unit) -> formatter -> (a,unit) matchi
         fprintf ppf "let (%a) = %a" (list_sep_d expression_variable) lst f b
     | Match_variant (lst, _) ->
         fprintf ppf "%a" (list_sep (matching_variant_case f) (tag "@.")) lst
-    | Match_bool {match_true ; match_false} ->
-        fprintf ppf "| True -> %a @.| False -> %a" f match_true f match_false
     | Match_list {match_nil ; match_cons = (hd, tl, match_cons, _)} ->
         fprintf ppf "| Nil -> %a @.| %a :: %a -> %a" f match_nil expression_variable hd expression_variable tl f match_cons
     | Match_option {match_none ; match_some = (some, match_some, _)} ->
@@ -163,8 +161,6 @@ and matching_type ppf m = match m with
       fprintf ppf "tuple"
   | Match_variant (lst, _) ->
       fprintf ppf "variant %a" (list_sep matching_variant_case_type (tag "@.")) lst
-  | Match_bool _ ->
-      fprintf ppf "boolean"
   | Match_list _ ->
       fprintf ppf "list"
   | Match_option _ ->
diff --git a/src/stages/3-ast_core/PP.ml b/src/stages/3-ast_core/PP.ml
index ac760dbba..cd269dcd6 100644
--- a/src/stages/3-ast_core/PP.ml
+++ b/src/stages/3-ast_core/PP.ml
@@ -76,8 +76,6 @@ and matching : type a . (formatter -> a -> unit) -> formatter -> (a,unit) matchi
         fprintf ppf "@[<hv>| (%a) ->@;<1 2>%a@]" (list_sep_d expression_variable) lst f b
     | Match_variant (lst, _) ->
         fprintf ppf "@[<hv>%a@]" (list_sep (matching_variant_case f) (tag "@ ")) lst
-    | Match_bool {match_true ; match_false} ->
-        fprintf ppf "@[<hv>| True ->@;<1 2>%a@ | False ->@;<1 2>%a@]" f match_true f match_false
     | Match_list {match_nil ; match_cons = (hd, tl, match_cons, _)} ->
         fprintf ppf "@[<hv>| Nil ->@;<1 2>%a@ | %a :: %a ->@;<1 2>%a@]" f match_nil expression_variable hd expression_variable tl f match_cons
     | Match_option {match_none ; match_some = (some, match_some, _)} ->
@@ -89,8 +87,6 @@ and matching_type ppf m = match m with
       fprintf ppf "tuple"
   | Match_variant (lst, _) ->
       fprintf ppf "variant %a" (list_sep matching_variant_case_type (tag "@.")) lst
-  | Match_bool _ ->
-      fprintf ppf "boolean"
   | Match_list _ ->
       fprintf ppf "list"
   | Match_option _ ->
diff --git a/src/stages/4-ast_typed/PP.ml b/src/stages/4-ast_typed/PP.ml
index 2eefdad38..08fd13a21 100644
--- a/src/stages/4-ast_typed/PP.ml
+++ b/src/stages/4-ast_typed/PP.ml
@@ -315,8 +315,6 @@ and matching : (formatter -> expression -> unit) -> _ -> matching_expr -> unit =
       fprintf ppf "let (%a) = %a" (list_sep_d expression_variable) vars f body
   | Match_variant {cases ; tv=_} ->
       fprintf ppf "%a" (list_sep (matching_variant_case f) (tag "@.")) cases
-  | Match_bool {match_true ; match_false} ->
-      fprintf ppf "| True -> %a @.| False -> %a" f match_true f match_false
   | Match_list {match_nil ; match_cons = {hd; tl; body; tv=_}} -> 
       fprintf ppf "| Nil -> %a @.| %a :: %a -> %a" f match_nil expression_variable hd expression_variable tl f body
   | Match_option {match_none ; match_some = {opt; body; tv=_}} ->
diff --git a/src/stages/4-ast_typed/misc.ml b/src/stages/4-ast_typed/misc.ml
index daa4efd6b..2075d2ac1 100644
--- a/src/stages/4-ast_typed/misc.ml
+++ b/src/stages/4-ast_typed/misc.ml
@@ -234,7 +234,6 @@ module Free_variables = struct
 
   and matching : (bindings -> expression -> bindings) -> bindings -> matching_expr -> bindings = fun f b m ->
     match m with
-    | Match_bool { match_true = t ; match_false = fa } -> union (f b t) (f b fa)
     | Match_list { match_nil = n ; match_cons = {hd; tl; body; tv=_} } -> union (f b n) (f (union (of_list [hd ; tl]) b) body)
     | Match_option { match_none = n ; match_some = {opt; body; tv=_} } -> union (f b n) (f (union (singleton opt) b) body)
     | Match_tuple { vars ; body ; tvs=_ } ->
diff --git a/src/stages/4-ast_typed/misc_smart.ml b/src/stages/4-ast_typed/misc_smart.ml
index 6b643d742..679789804 100644
--- a/src/stages/4-ast_typed/misc_smart.ml
+++ b/src/stages/4-ast_typed/misc_smart.ml
@@ -91,10 +91,6 @@ module Captured_variables = struct
 
   and matching : (bindings -> expression -> bindings result) -> bindings -> matching_expr -> bindings result = fun f b m ->
     match m with
-    | Match_bool { match_true = t ; match_false = fa } ->
-      let%bind t' = f b t in
-      let%bind fa' = f b fa in
-      ok @@ union t' fa'
     | Match_list { match_nil = n ; match_cons = {hd; tl; body; tv=_} } ->
       let%bind n' = f b n in
       let%bind c' = f (union (of_list [hd ; tl]) b) body in
diff --git a/src/stages/4-ast_typed/types.ml b/src/stages/4-ast_typed/types.ml
index 450559d1b..4b0882119 100644
--- a/src/stages/4-ast_typed/types.ml
+++ b/src/stages/4-ast_typed/types.ml
@@ -88,10 +88,6 @@ type literal =
   | Literal_void
   | Literal_operation of packed_internal_operation
 
-type matching_content_bool = {
-    match_true : expression ;
-    match_false : expression ;
-  }
 
 and matching_content_cons = {
     hd : expression_variable;
@@ -139,7 +135,6 @@ and matching_content_variant = {
   }
 
 and matching_expr =
-  | Match_bool    of matching_content_bool
   | Match_list    of matching_content_list
   | Match_option  of matching_content_option
   | Match_tuple   of matching_content_tuple
diff --git a/src/stages/common/types.ml b/src/stages/common/types.ml
index fff182fc4..31582d372 100644
--- a/src/stages/common/types.ml
+++ b/src/stages/common/types.ml
@@ -169,10 +169,6 @@ type literal =
   | Literal_operation of
       Memory_proto_alpha.Protocol.Alpha_context.packed_internal_operation
 and ('a,'tv) matching_content =
-  | Match_bool of {
-      match_true : 'a ;
-      match_false : 'a ;
-    }
   | Match_list of {
       match_nil : 'a ;
       match_cons : expression_variable * expression_variable * 'a * 'tv;

From 8d59389f7d7787120dd906ce7b2e933a7c2bbeb5 Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Wulfman <pierre.emmanuel.wulfman@gmail.com>
Date: Wed, 29 Apr 2020 19:39:46 +0200
Subject: [PATCH 2/2] review

---
 src/passes/10-interpreter/interpreter.ml | 3 ++-
 src/passes/10-transpiler/transpiler.ml   | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/passes/10-interpreter/interpreter.ml b/src/passes/10-interpreter/interpreter.ml
index 949a832b1..85c15c6fb 100644
--- a/src/passes/10-interpreter/interpreter.ml
+++ b/src/passes/10-interpreter/interpreter.ml
@@ -342,7 +342,8 @@ and eval : Ast_typed.expression -> env -> value result
         let {hd;tl;body;tv=_} = cases.match_cons in
         let env' = Env.extend (Env.extend env (hd,head)) (tl, V_List tail) in
         eval body env'
-      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false"; body=match_false}];_}, V_Ct (C_bool b) ->
+      | Match_variant {cases=[{constructor=Constructor t;body=match_true};{constructor=Constructor f; body=match_false}];_}, V_Ct (C_bool b)
+        when String.equal t "true" && String.equal f "false" ->
         if b then eval match_true env
         else eval match_false env
       | Match_variant {cases ; tv=_} , V_Construct (matched_c , proj) ->
diff --git a/src/passes/10-transpiler/transpiler.ml b/src/passes/10-transpiler/transpiler.ml
index 4bf78a0c9..a7ca1f555 100644
--- a/src/passes/10-transpiler/transpiler.ml
+++ b/src/passes/10-transpiler/transpiler.ml
@@ -580,7 +580,8 @@ and transpile_annotated_expression (ae:AST.expression) : expression result =
           in
           return @@ E_if_cons (expr' , nil , cons)
         )
-      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false";body=match_false}];_} ->
+      | Match_variant {cases=[{constructor=Constructor t;body=match_true};{constructor=Constructor f;body=match_false}];_}
+        when String.equal t "true" && String.equal f "false" ->
           let%bind (t , f) = bind_map_pair (transpile_annotated_expression) (match_true, match_false) in
           return @@ E_if_bool (expr', t, f)
       | Match_variant {cases ; tv} -> (
@@ -703,7 +704,8 @@ and transpile_recursive {fun_name; fun_type; lambda} =
           in
           return @@ E_if_cons (expr , nil , cons)
         )
-      | Match_variant {cases=[{constructor=Constructor "true";body=match_true};{constructor=Constructor "false";body=match_false}];_} ->
+      | Match_variant {cases=[{constructor=Constructor t;body=match_true};{constructor=Constructor f;body=match_false}];_}
+        when String.equal t "true" && String.equal f "false" ->
           let%bind (t , f) = bind_map_pair (replace_callback fun_name loop_type shadowed) (match_true, match_false) in
           return @@ E_if_bool (expr, t, f)
       | Match_variant {cases;tv} -> (