Add support for dcalc plugins

previously only lcalc and scalc where available

compiler/driver.ml

@@ -289,6 +289,13 @@ let driver source_file (options : Cli.options) : int =
                   (Shared_ast.Expr.format ~debug:options.debug prgm.decl_ctx)
                   result)
               results
+          | `Plugin (Plugin.Dcalc p) ->
+            let output_file, _ = get_output_format ~ext:p.Plugin.extension () in
+            Cli.debug_print "Compiling program through backend \"%s\"..."
+              p.Plugin.name;
+            p.Plugin.apply ~source_file ~output_file ~scope:options.ex_scope
+              (Shared_ast.Program.untype prgm)
+              type_ordering
           | (`OCaml | `Interpret_Lcalc | `Python | `Lcalc | `Scalc | `Plugin _)
             as backend -> (
             Cli.debug_print "Compiling program into lambda calculus...";
@@ -375,6 +382,7 @@ let driver source_file (options : Cli.options) : int =
                 Cli.debug_print "Writing to %s..."
                   (Option.value ~default:"stdout" output_file);
                 Lcalc.To_ocaml.format_program fmt prgm type_ordering
+              | `Plugin (Plugin.Dcalc _) -> assert false
               | `Plugin (Plugin.Lcalc p) ->
                 let output_file, _ =
                   get_output_format ~ext:p.Plugin.extension ()
@@ -411,7 +419,7 @@ let driver source_file (options : Cli.options) : int =
                   with_output
                   @@ fun fmt ->
                   Scalc.To_python.format_program fmt prgm type_ordering
-                | `Plugin (Plugin.Lcalc _) -> assert false
+                | `Plugin (Plugin.Dcalc _ | Plugin.Lcalc _) -> assert false
                 | `Plugin (Plugin.Scalc p) ->
                   let output_file, _ = get_output ~ext:p.Plugin.extension () in
                   Cli.debug_print "Compiling program through backend \"%s\"..."

compiler/plugin.ml

@@ -31,16 +31,22 @@ type 'ast gen = {
 }
 
 type t =
+  | Dcalc of Shared_ast.untyped Dcalc.Ast.program gen
   | Lcalc of Shared_ast.untyped Lcalc.Ast.program gen
   | Scalc of Scalc.Ast.program gen
 
-let name = function Lcalc { name; _ } | Scalc { name; _ } -> name
+let name = function
+  | Dcalc { name; _ } | Lcalc { name; _ } | Scalc { name; _ } -> name
+
 let backend_plugins : (string, t) Hashtbl.t = Hashtbl.create 17
 
 let register t =
   Hashtbl.replace backend_plugins (String.lowercase_ascii (name t)) t
 
 module PluginAPI = struct
+  let register_dcalc ~name ~extension apply =
+    register (Dcalc { name; extension; apply })
+
   let register_lcalc ~name ~extension apply =
     register (Lcalc { name; extension; apply })
 

compiler/plugin.mli

@@ -33,6 +33,7 @@ type 'ast gen = {
 }
 
 type t =
+  | Dcalc of Shared_ast.untyped Dcalc.Ast.program gen
   | Lcalc of Shared_ast.untyped Lcalc.Ast.program gen
   | Scalc of Scalc.Ast.program gen
 
@@ -48,6 +49,12 @@ val load_dir : string -> unit
 (** {2 plugin-facing API} *)
 
 module PluginAPI : sig
+  val register_dcalc :
+    name:string ->
+    extension:string ->
+    Shared_ast.untyped Dcalc.Ast.program plugin_apply_fun_typ ->
+    unit
+
   val register_lcalc :
     name:string ->
     extension:string ->