Merge branch er433/monomorphisation/commute with refs/heads/dev into refs/merge-requests/2763/train

changelog/2763

+
+author: er433
+description: "\\n"
+merge_request: '2763'
+title: "Monomorphisation: add commutation with `let`"
+type: fixed
+            
\ No newline at end of file

src/bin/expect_tests/polymorphism.ml

@@ -4,6 +4,10 @@ let test basename = "./" ^ basename
 let pwd = Caml.Sys.getcwd ()
 let () = Caml.Sys.chdir "../../test/contracts/polymorphism/"
 
+let%expect_test _ =
+  run_ligo_good [ "compile"; "contract"; test "monomorphisation_let.mligo" ];
+  [%expect {| { parameter unit ; storage int ; code { CDR ; NIL operation ; PAIR } } |}]
+
 let%expect_test _ =
   run_ligo_good
     [ "compile"

src/passes/13-self_ast_aggregated/monomorphisation.ml

@@ -4,6 +4,7 @@ open Ligo_prim
 module Row = AST.Row
 
 let fold_map_expression = AST.Helpers.fold_map_expression
+let map_expression = AST.Helpers.map_expression
 let poly_name ~loc v = Value_var.fresh_like ~loc v
 
 module Instance = struct
@@ -459,8 +460,57 @@ let check_if_polymorphism_present ~raise e =
   e
 
 
+(* This function commutes `(let x = t in u)@{T}` into `let x = t in
+   (u@{T})` to cover more cases, as the next pass assumes that type
+   instantiation was on variable or another type instance *)
+let commute e =
+  let e =
+    map_expression
+      (fun e ->
+        match e.expression_content with
+        | E_type_inst
+            { forall =
+                { expression_content =
+                    E_let_in { let_binder; rhs; let_result; attributes }
+                ; _
+                }
+            ; type_
+            } ->
+          let let_result =
+            { let_result with
+              expression_content = E_type_inst { forall = let_result; type_ }
+            ; type_expression = e.type_expression
+            }
+          in
+          { e with
+            expression_content = E_let_in { let_binder; rhs; let_result; attributes }
+          }
+        | E_type_inst
+            { forall =
+                { expression_content =
+                    E_let_mut_in { let_binder; rhs; let_result; attributes }
+                ; _
+                }
+            ; type_
+            } ->
+          let let_result =
+            { let_result with
+              expression_content = E_type_inst { forall = let_result; type_ }
+            ; type_expression = e.type_expression
+            }
+          in
+          { e with
+            expression_content = E_let_mut_in { let_binder; rhs; let_result; attributes }
+          }
+        | _ -> e)
+      e
+  in
+  e
+
+
 let mono_polymorphic_expr ~raise e =
   let e = Deduplicate_binders.program e in
+  let e = commute e in
   let _, m = mono_polymorphic_expression ~raise Data.empty e in
   let m = check_if_polymorphism_present ~raise m in
   m

src/test/contracts/polymorphism/monomorphisation_let.mligo

+let empty (n : nat) : 42 sapling_state = let _n = n in Tezos.sapling_empty_state
+
+let main (_, s : unit * int) : operation list * int =
+  let s4 = empty in
+  let () = ignore s4 in
+  (([] : operation list), s)