A PPX for Bam

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         ocaml-compiler: [
             # OCaml LTS version
-            ocaml.4.14.1,
+            ocaml.4.14.2,
             # ocaml-system for Fedora 39
             ocaml.5.0.0,
             # ocaml-system for Archlinux

bam-ppx.opam

@@ -0,0 +1,34 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "A PPX deriving generators for OCaml types"
+description:
+  "Provides a way to automatically get generators for a given type"
+maintainer: ["François Thiré"]
+authors: ["François Thiré"]
+license: "MIT"
+tags: ["test" "pbt" "shrinking" "internal" "bam" "ppx"]
+homepage: "https://github.com/francoisthire/bam"
+doc: "https://francoisthire.github.io/bam/"
+bug-reports: "https://github.com/francoisthire/bam/issues"
+depends: [
+  "ocaml"
+  "dune" {>= "3.7"}
+  "ppxlib" {<= "0.32.0"}
+  "dmap" {>= "0.5"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/francoisthire/bam.git"

dune-project

@@ -7,9 +7,9 @@
 (source
  (github francoisthire/bam))
 
-(authors "François Thiré")
+(authors "Fran\195\167ois Thir\195\169")
 
-(maintainers "François Thiré")
+(maintainers "Fran\195\167ois Thir\195\169")
 
 (license MIT)
 
@@ -18,18 +18,50 @@
 (package
  (name bam)
  (synopsis "A property-based testing library with internal shrinking")
- (description "A property-based testing allowing to define generators with internal shrinking easily")
- (depends (ocaml (>= 4.14)) (dune (>= 3.7)) pringo (zarith (>= 1.13)) (odoc :with-doc) (tezt :with-test))
+ (description
+  "A property-based testing allowing to define generators with internal shrinking easily")
+ (depends
+  (ocaml
+   (>= 4.14))
+  (dune
+   (>= 3.7))
+  pringo
+  (zarith
+   (>= 1.13))
+  (odoc :with-doc)
+  (tezt :with-test))
  (tags
   (test pbt shrinking internal)))
 
+(package
+ (name bam-ppx)
+ (synopsis "A PPX deriving generators for OCaml types")
+ (description
+  "Provides a way to automatically get generators for a given type")
+ (depends
+  ocaml
+  dune
+  (ppxlib
+   (<= 0.32.0))
+  (dmap
+   (>= 0.5))
+  (odoc :with-doc))
+ (tags
+  (test pbt shrinking internal bam ppx)))
+
 (package
  (name tezt-bam)
  (synopsis "A plugin of [bam] for Tezt")
  (description "Provides a way to register PBT tests with Tezt")
- (depends ocaml dune tezt bam (mtime (>= 2.0)) (odoc :with-doc))
+ (depends
+  ocaml
+  dune
+  tezt
+  bam
+  (mtime
+   (>= 2.0))
+  (odoc :with-doc))
  (tags
   (test tezt pbt shrinking internal bam)))
 
-
 ; See the complete stanza docs at https://dune.readthedocs.io/en/stable/dune-files.html#dune-project

lib_ppx/attributes.ml

@@ -0,0 +1,232 @@
+open Ppxlib
+include Attribute
+open Runtime
+open Ty
+
+module State_monad = struct
+  type ('node, 'state) t = 'node -> 'state -> 'node * 'state
+
+  module Syntax = struct
+    let ( let* ) x f ct state =
+      let ct, state = x ct state in
+      f () ct state
+
+    let return ct state = (ct, state)
+  end
+end
+
+let get_attribute attribute node runtime =
+  match Attribute.consume_res attribute node with
+  | Error _ ->
+      (node, runtime)
+  | Ok (Some (ct, attribute)) ->
+      (ct, attribute runtime)
+  | Ok None ->
+      (node, runtime)
+
+let update :
+    ('node, 'state -> 'state) Attribute.t list -> ('node, 'state) State_monad.t
+    =
+ fun attributes ->
+  let open State_monad.Syntax in
+  let base node runtime = (node, runtime) in
+  List.fold_left
+    (fun acc attr ->
+      let* () = acc in
+      let* () = get_attribute attr in
+      return )
+    base attributes
+
+module Generic : sig
+  (* This module declares a set of attributes that can be included at any context. Any of those attributes can modify the runtime environment. *)
+  val attributes :
+    'node Context.t -> ('node, Runtime.t -> Runtime.t) Attribute.t list
+end = struct
+  let min context =
+    Attribute.declare "gen.min" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun min runtime ->
+        {runtime with limits= {runtime.limits with min= Some min}} )
+
+  let max context =
+    Attribute.declare "gen.max" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun max runtime ->
+        {runtime with limits= {runtime.limits with max= Some max}} )
+
+  let int_min context =
+    Attribute.declare "gen.int.min" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun min runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_min= Ranged_dmap.add Int min runtime.limits.ranged_min } }
+        )
+
+  let int_max context =
+    Attribute.declare "gen.int.max" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun max runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_max= Ranged_dmap.add Int max runtime.limits.ranged_max } }
+        )
+
+  let int32_min context =
+    Attribute.declare "gen.int32.min" context
+      Ast_pattern.(single_expr_payload (eint32 __))
+      (fun min runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_min= Ranged_dmap.add Int32 min runtime.limits.ranged_min }
+        } )
+
+  let int32_max context =
+    Attribute.declare "gen.int32.max" context
+      Ast_pattern.(single_expr_payload (eint32 __))
+      (fun max runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_max= Ranged_dmap.add Int32 max runtime.limits.ranged_max }
+        } )
+
+  let int64_min context =
+    Attribute.declare "gen.int64.min" context
+      Ast_pattern.(single_expr_payload (eint64 __))
+      (fun min runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_min= Ranged_dmap.add Int64 min runtime.limits.ranged_min }
+        } )
+
+  let int64_max context =
+    Attribute.declare "gen.int64.max" context
+      Ast_pattern.(single_expr_payload (eint64 __))
+      (fun max runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              ranged_max= Ranged_dmap.add Int64 max runtime.limits.ranged_max }
+        } )
+
+  let size_min context =
+    Attribute.declare "gen.size.min" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun size_min runtime ->
+        { runtime with
+          limits= {runtime.limits with size_min= Some (Int.max 0 size_min)} } )
+
+  let size_max context =
+    Attribute.declare "gen.size.max" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun size_max runtime ->
+        {runtime with limits= {runtime.limits with size_max= Some size_max}} )
+
+  let string_size_min context =
+    Attribute.declare "gen.string.size.min" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun size_min runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              sized_min=
+                Sized_map.add (E String) (Int.max 0 size_min)
+                  runtime.limits.sized_min } } )
+
+  let string_size_max context =
+    Attribute.declare "gen.string.size.max" context
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun size_max runtime ->
+        { runtime with
+          limits=
+            { runtime.limits with
+              sized_max=
+                Sized_map.add (E String) (Int.max 0 size_max)
+                  runtime.limits.sized_max } } )
+
+  let overrides =
+    [ ("unit", E Unit)
+    ; ("bool", E Bool)
+    ; ("char", E Char)
+    ; ("int", E (Ranged Int))
+    ; ("int32", E (Ranged Int32))
+    ; ("int64", E (Ranged Int64))
+    ; ("string", E (Sized String))
+    ; ("bytes", E (Sized Bytes))
+    ; ("list", E (Sized List))
+    ; ("array", E (Sized Array))
+    ; ("seq", E (Sized Seq))
+    ; ("option", E Option)
+    ; ("any", E Any) ]
+
+  let gen_override context (name, ty) =
+    Attribute.declare ("gen." ^ name) context
+      Ast_pattern.(single_expr_payload __)
+      (fun gen runtime ->
+        {runtime with override= Ty.Map.add ty gen runtime.override} )
+
+  let gen_overrides context = overrides |> List.map (gen_override context)
+
+  let gen context =
+    Attribute.declare "gen.gen" context
+      Ast_pattern.(single_expr_payload __)
+      (fun gen runtime -> {runtime with gen= Some gen})
+
+  let attributes context =
+    [ min context
+    ; max context
+    ; int_min context
+    ; int_max context
+    ; int32_min context
+    ; int32_max context
+    ; int64_min context
+    ; int64_max context
+    ; size_min context
+    ; size_max context
+    ; string_size_min context
+    ; string_size_max context
+    ; gen context ]
+    @ gen_overrides context
+end
+
+module Type_declaration : sig
+  val update : (type_declaration, Runtime.t) State_monad.t
+end = struct
+  let attributes = Generic.attributes Attribute.Context.type_declaration
+
+  let update = update attributes
+end
+
+module Label_declaration : sig
+  val update : (label_declaration, Runtime.t) State_monad.t
+end = struct
+  let attributes = Generic.attributes Attribute.Context.label_declaration
+
+  let update = update attributes
+end
+
+module Constructor_declaration : sig
+  val update : (constructor_declaration, Runtime.t) State_monad.t
+end = struct
+  let attributes = Generic.attributes Attribute.Context.constructor_declaration
+
+  let weight =
+    Attribute.declare "gen.weight" Attribute.Context.constructor_declaration
+      Ast_pattern.(single_expr_payload (eint __))
+      (fun weight runtime -> {runtime with weight= Some weight})
+
+  let update = update (weight :: attributes)
+end
+
+module Core_type : sig
+  val update : (core_type, Runtime.t) State_monad.t
+end = struct
+  let attributes = Generic.attributes Attribute.Context.core_type
+
+  let update = update attributes
+end

lib_ppx/attributes.mli

@@ -0,0 +1,20 @@
+open Ppxlib
+
+include module type of Attribute
+
+module Core_type : sig
+  val update : core_type -> Runtime.t -> core_type * Runtime.t
+end
+
+module Label_declaration : sig
+  val update : label_declaration -> Runtime.t -> label_declaration * Runtime.t
+end
+
+module Constructor_declaration : sig
+  val update :
+    constructor_declaration -> Runtime.t -> constructor_declaration * Runtime.t
+end
+
+module Type_declaration : sig
+  val update : type_declaration -> Runtime.t -> type_declaration * Runtime.t
+end

lib_ppx/bam_ppx.ml

@@ -0,0 +1,12 @@
+let deriving_str_type_declaration ~ctxt:_ (rec_flag, type_declarations) =
+  Deriver.derive_type_declarations rec_flag type_declarations
+
+let str_type_decl =
+  Ppxlib.Deriving.Generator.V2.make_noarg deriving_str_type_declaration
+
+let deriving_str_module_type_decl = Deriver.derive_module_type_declaration
+
+let str_module_type_decl =
+  Ppxlib.Deriving.Generator.V2.make_noarg deriving_str_module_type_decl
+
+let deriver = Ppxlib.Deriving.add "gen" ~str_type_decl ~str_module_type_decl