Make it work on OCaml v4.14.0 and above

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
    - Algebraic simplification now requires operands to be either variables or constants, not compound values.
  - Eliminate let-bindings for "innocent terms" via postprocessing.
    - Innocent terms are variables, integer constants, and zero-arity constructor calls.
+ - The minimum supported OCaml version is now 4.14.0.
 
 ### Removed
 

bin/main.ml

@@ -296,14 +296,14 @@ let cut_list list =
       Array.(to_list first_10 @ [ middle ] @ to_list last_10))
 ;;
 
-let its_over ?(reduction_path = []) msg =
+let its_over ?reduction_path msg =
     Spectrum.Simple.eprintf "@{<bold,red>error:@} %s\n" msg;
-    if not (List.is_empty reduction_path)
-    then
+    reduction_path
+    |> Option.iter (fun reduction_path ->
       Spectrum.Simple.eprintf
         "%s@{<bold,aqua>note:@} While reducing %s\n"
         tab
-        (String.concat " -> " (cut_list reduction_path));
+        (String.concat " -> " (cut_list reduction_path)));
     exit 1
 ;;
 

dune-project

@@ -1,4 +1,4 @@
-(lang dune 3.15)
+(lang dune 3.14)
 
 (using menhir 3.0)
 
@@ -24,7 +24,7 @@
  (synopsis "A modern supercompiler for call-by-value functional languages")
  (depends
   (ocaml
-   (>= 5.1))
+   (>= 4.14))
   dune
   pprint
   (checked_oint

lib/abstract_syntax/program.ml

@@ -60,16 +60,16 @@ let output ~oc ({ f_rules; g_rules; _ } : t) =
     in
     let f_rules =
         f_rules
-        |> F_rules.to_list
+        |> F_rules.bindings
         |> List.map (fun (f, (params, body)) -> f, params, Term.to_string body)
     in
     let g_rules =
         g_rules
-        |> G_rules_by_name.to_list
+        |> G_rules_by_name.bindings
         |> List.map (fun (g, rules) ->
           ( g
           , rules
-            |> G_rules_by_pattern.to_list
+            |> G_rules_by_pattern.bindings
             |> List.map (fun (c, (c_params, params, body)) ->
               c, c_params, params, Term.to_string body) ))
     in

lib/codegen/c_codegen.ml

@@ -200,11 +200,11 @@ end = struct
 
   and gen_data_call ~ctx (c, args) =
       remember_constructor c;
-      if List.is_empty args
-      then
+      match args with
+      | [] ->
         ( c_function_call (id "MZ_EMPTY_DATA", [ c_identifier_expression (gen_op c) ])
         , Symbol_set.empty )
-      else (
+      | _ ->
         let args_gen = List.map (gen_thunk_function ~ctx) args in
         let args_fv =
             Symbol_set.(
@@ -216,7 +216,7 @@ end = struct
               ; c_integer_constant_expression (index (List.length args))
               ]
               @ List.map (gen_thunk_call ~ctx) args_gen )
-        , args_fv ))
+        , args_fv )
 
   and gen_thunk_call ~ctx (thunk, env) =
       match thunk with
@@ -385,9 +385,9 @@ end = struct
         let declaration_specifiers = [ c_static; c_typedef_name (id "mz_Value") ] in
         let identifier = gen_op f in
         let parameter_list =
-            if List.is_empty params
-            then []
-            else
+            match params with
+            | [] -> []
+            | _ ->
               [ c_parameter_declaration
                   ( [ c_typedef_name (id "mz_ArgsPtr") ]
                   , Some (c_identifier_declarator (id "args")) )
@@ -416,9 +416,9 @@ end = struct
   ;;
 
   let main_wrapper_body =
-      if List.is_empty main_params
-      then [ c_return_statement (c_function_call (gen_op main_symbol, [])) ]
-      else
+      match main_params with
+      | [] -> [ c_return_statement (c_function_call (gen_op main_symbol, [])) ]
+      | _ ->
         [ c_return_statement
             (c_function_call
                ( id "MZ_CALL_MAIN"

lib/evaluator.ml

@@ -106,7 +106,7 @@ let run_exn (input : Raw_program.t) =
         go ~env body
     in
     let main_params, t = find_rule ~program (Symbol.of_string "main") in
-    if not (List.is_empty main_params)
-    then (Util.panic [@coverage off]) "The main function cannot accept parameters";
-    go ~env:Symbol_map.empty t
+    match main_params with
+    | [] -> go ~env:Symbol_map.empty t
+    | _ -> (Util.panic [@coverage off]) "The main function cannot accept parameters"
 ;;

lib/mazeppa.ml

@@ -9,9 +9,7 @@ exception Panic of string
 
 let wrap_panic f =
     try f () with
-    | Util.Panic { msg; reduction_path } ->
-      assert (List.is_empty reduction_path);
-      raise (Panic msg)
+    | Util.Panic { msg; reduction_path = _ } -> raise (Panic msg)
 ;;
 
 let supercompile (input : Raw_program.t) : Raw_program.t =

lib/raw_syntax/converter.ml

@@ -169,7 +169,8 @@ let to_program (input : t) : Program.t =
         let rules =
             cases
             |> List.map (fun ((c, c_params), t) -> c, (c_params, cases_fv_list, t))
-            |> Program.G_rules_by_pattern.of_list
+            |> List.to_seq
+            |> Program.G_rules_by_pattern.of_seq
         in
         let fresh_g = Gensym.emit g_gensym in
         g_rules := Program.G_rules_by_name.add fresh_g rules !g_rules;

mazeppa.opam

@@ -9,8 +9,8 @@ homepage: "https://github.com/mazeppa-dev/mazeppa"
 doc: "https://github.com/mazeppa-dev/mazeppa"
 bug-reports: "https://github.com/mazeppa-dev/mazeppa/issues"
 depends: [
-  "ocaml" {>= "5.1"}
-  "dune" {>= "3.15"}
+  "ocaml" {>= "4.14"}
+  "dune" {>= "3.14"}
   "pprint"
   "checked_oint" {>= "0.2.0"}
   "ppx_deriving"

test/test_mazeppa.ml

@@ -26,7 +26,9 @@ let list xs =
       (Raw_term.call ("Nil", []))
 ;;
 
-let make_subst list = list |> List.map (fun (x, t) -> symbol x, t) |> Symbol_map.of_list
+let make_subst list =
+    list |> List.map (fun (x, t) -> symbol x, t) |> List.to_seq |> Symbol_map.of_seq
+;;
 
 let print_constants () =
     let check ~expected const =