Remove singleton inductive type

src/passes/1-parser/pascaligo/AST.ml

@@ -406,8 +406,7 @@ and lhs =
   Path    of path
 | MapPath of map_lookup reg
 
-and rhs =
-      Expr of expr
+and rhs = expr
 
 and loop =
   While of while_loop reg
@@ -757,8 +756,7 @@ let lhs_to_region : lhs -> Region.t = function
   Path path -> path_to_region path
 | MapPath {region; _} -> region
 
-let rhs_to_region = function
-      Expr e -> expr_to_region e
+let rhs_to_region = expr_to_region
 
 let selection_to_region = function
   FieldName {region; _}

src/passes/1-parser/pascaligo/AST.mli

@@ -390,8 +390,7 @@ and lhs =
   Path    of path
 | MapPath of map_lookup reg
 
-and rhs =
-      Expr of expr
+and rhs = expr
 
 and loop =
   While of while_loop reg

src/passes/1-parser/pascaligo/Parser.mly

@@ -591,7 +591,7 @@ assignment:
     in {region; value}}
 
 rhs:
-  expr  { Expr $1 }
+  expr  { $1 }
 
 lhs:
   path       {    Path $1 }

src/passes/1-parser/pascaligo/ParserLog.ml

@@ -309,8 +309,7 @@ and print_assignment {value; _} =
   print_token assign ":=";
   print_rhs rhs
 
-and print_rhs = function
-      Expr e -> print_expr e
+and print_rhs e = print_expr e
 
 and print_lhs = function
   Path path -> print_path path

src/passes/2-simplify/pascaligo.ml

@@ -780,9 +780,7 @@ and simpl_single_instruction : Raw.single_instr -> (_ -> expression result) resu
     )
   | Assign a -> (
       let (a , loc) = r_split a in
-      let%bind value_expr = match a.rhs with
-        | Expr e -> simpl_expression e
-      in
+      let%bind value_expr = simpl_expression a.rhs in
       match a.lhs with
         | Path path -> (
             let (name , path') = simpl_path path in