Add ppx_tester

Signed-off-by: Kakadu <Kakadu@pm.me>

ppx/dune

@@ -23,6 +23,12 @@
  (libraries ppx_distrib)
  (modules pp_distrib))
 
+(executable
+ (public_name pp_tester)
+ (package OCanren-ppx)
+ (libraries ppx_tester)
+ (modules pp_tester))
+
 (executable
  (public_name pp_deriving_reify)
  (package OCanren-ppx)

ppx/pp_tester.ml

@@ -0,0 +1,12 @@
+(*
+ * OCanren PPX
+ * Copyright (C) 2016-2023
+ *   Dmitrii Kosarev aka Kakadu
+ * St.Petersburg State University, JetBrains Research
+ *)
+
+let () =
+  (* TODO: Invent something for margins
+  https://github.com/ocaml-ppx/ppxlib/issues/273*)
+  Ppxlib.Driver.standalone ()
+;;

ppx/reify/deriving_reify.ml

@@ -17,7 +17,26 @@
  * (enclosed in the file COPYING).
  *)
 
-(* module Pprintast_ = Pprintast *)
+(*
+# type 'a t = 'a OCanren.Std.List.injected [@@deriving reify];;
+type 'a t = 'a OCanren.Std.List.injected
+val reify :
+  ('a, 'b) OCanren__.Logic.Reifier.t ->
+  ('a OCanren.Std.List.injected, 'b OCanren.Std.List.logic)
+  OCanren__.Logic.Reifier.t = <fun>
+val prj_exn :
+  ('a, 'b) OCanren__.Logic.Reifier.t ->
+  ('a OCanren.Std.List.injected, 'b OCanren.Std.List.ground)
+  OCanren__.Logic.Reifier.t = <fun>
+
+# [%reify: GT.int OCanren.Std.List.injected];;
+- : ('_weak2 OCanren.ilogic OCanren.Std.List.injected,
+     '_weak2 OCanren.logic OCanren.Std.List.logic)
+    OCanren__.Logic.Reifier.t
+= <fun>
+
+
+*)
 open Ppxlib
 open Stdppx
 

ppx/tester/dune

@@ -0,0 +1,10 @@
+(library
+ (name ppx_tester)
+ (public_name OCanren-ppx.ppx_tester)
+ (kind ppx_rewriter)
+ (libraries ppxlib)
+ (modules ppx_tester)
+ (flags
+  (:standard -linkall))
+ (preprocess
+  (pps ppxlib.metaquot)))

ppx/tester/ppx_tester.ml

@@ -0,0 +1,83 @@
+(*
+ * OCanren. PPX syntax extensions.
+ * Copyright (C) 2016-2023
+ *   Dmitrii Kosarev aka Kakadu
+ * St.Petersburg State University, JetBrains Research
+ *)
+
+(**
+  An extension that allows not to write errornous qh, qrh and stuff like that.
+  It looks at number of lambdas in the last argument, and insert numberals as penultimate argument.
+
+  Expands
+
+    {[ let __ _ = [%tester runR OCanren.reify show_int show_intl (fun q -> q === !!1)] ]}
+
+  to
+
+  {[
+    let __ _ =
+      runR OCanren.reify show_int show_intl q qh
+        ("<string repr of goal>", (fun q -> q === (!! 1)))
+  ]}
+
+*)
+
+open Ppxlib
+
+let string_of_expression e =
+  Format.set_margin 1000;
+  Format.set_max_indent 0;
+  let ans = Format.asprintf "%a" Pprintast.expression e in
+  ans
+;;
+
+let name = "tester"
+
+let () =
+  let extensions =
+    let pattern =
+      let open Ast_pattern in
+      pstr
+        (pstr_eval
+           (pexp_apply
+              __
+              ((nolabel ** __) ^:: (nolabel ** __) ^:: (nolabel ** __) ^:: (nolabel ** __) ^:: nil))
+           nil
+        ^:: nil)
+    in
+    [ Extension.declare
+        name
+        Extension.Context.Expression
+        pattern
+        (fun ~loc ~path:_ runner reifier shower n realtion ->
+          let open Ppxlib.Ast_builder.Default in
+          let count =
+            let rec helper acc e =
+              match e.pexp_desc with
+              | Pexp_fun (_, _, _, body) -> helper (1 + acc) body
+              | _ -> acc
+            in
+            helper 0 realtion
+          in
+          let middle =
+            match count with
+            | 0 -> failwith "Bad syntax"
+            | 1 -> [ [%expr OCanren.q]; [%expr qh] ]
+            | 2 -> [ [%expr OCanren.qr]; [%expr qrh] ]
+            | 3 -> [ [%expr OCanren.qrs]; [%expr qrsh] ]
+            | 4 -> [ [%expr OCanren.qrst]; [%expr qrsth] ]
+            | _ -> failwith (Printf.sprintf "5 and more arguments are not supported")
+          in
+          let last =
+            let s = string_of_expression @@ realtion in
+            let open Ppxlib.Ast_builder.Default in
+            [%expr [%e pexp_constant ~loc (Pconst_string (s, loc, None))], [%e realtion]]
+          in
+          pexp_apply ~loc runner
+          @@ List.map (fun e -> Nolabel, e)
+          @@ List.concat [ [ reifier; shower; n ]; middle; [ last ] ])
+    ]
+  in
+  Ppxlib.Driver.register_transformation ~extensions name
+;;

regression_ppx/dune

@@ -91,7 +91,7 @@
    ;
    ))
  (preprocess
-  (pps OCanren-ppx.ppx_distrib GT.ppx_all -- -pretty))
+  (pps OCanren-ppx.ppx_tester OCanren-ppx.ppx_distrib GT.ppx_all -- -pretty))
  (libraries OCanren OCanren.tester))
 
 (executables

regression_ppx/test009.ml

@@ -21,3 +21,16 @@ end = struct
 
   type nonrec ground = (GT.int, GT.bool) t]
 end
+
+let () =
+  let open OCanren in
+  let open Tester in
+  run_r
+    OCanren.reify
+    (GT.show OCanren.logic (GT.show GT.int))
+    1
+    q
+    Tester.qh
+    ("<string repr of goal>", fun q -> q === inj 1);
+  [%tester run_r OCanren.reify (GT.show OCanren.logic (GT.show GT.int)) 1 (fun q -> q === inj 1)]
+;;

regression_ppx/test009.t

@@ -54,6 +54,21 @@
       let lBool _x__002_ = OCanren.inji (LBool _x__002_)
     end
   end
+
+  let () =
+    let open OCanren in
+    let open Tester in
+    run_r OCanren.reify
+      (GT.show OCanren.logic (GT.show GT.int))
+      1 q Tester.qh
+      ("<string repr of goal>", fun q -> q === inj 1) ;
+    [%tester run_r OCanren.reify (GT.show OCanren.logic (GT.show GT.int)) 1 (fun q -> q === inj 1)]
 
   $ ./test009.exe
   test009
+  <string repr of goal>, 1 answer {
+  q=1;
+  }
+  fun q -> q === (inj 1), 1 answer {
+  q=1;
+  }