Merge pull request #31 from mbarbin/named-traits

Name traits in preparation for refactor

doc/docs/reference/hello_world.md

@@ -11,25 +11,31 @@ end
 
 type show = [ `Show ]
 
-type (_, _, _) Provider.Trait.t +=
-  Show : ('t, (module S with type t = 't), [> show ]) Provider.Trait.t
+module Show : sig
+  val t : ('t, (module S with type t = 't), [> show ]) Provider.Trait.t
+end  = struct
+  type (_, _, _) Provider.Trait.t +=
+    | Show : ('t, (module S with type t = 't), [> show ]) Provider.Trait.t
+
+  let t = Show
+end
 
 let print (Provider.T { t; handler }) =
-  let module M = (val Provider.Handler.lookup handler ~trait:Show) in
+  let module M = (val Provider.Handler.lookup handler ~trait:Show.t) in
   print_endline (M.show t)
 
 let string_provider t =
   let handler =
     Provider.Handler.make
-      [ Provider.Trait.implement Show
-          ~impl:(module struct type t = string let show = Fun.id end)
+      [ Provider.Trait.implement Show.t
+          ~impl:(module struct type t = string let show = String.uppercase_ascii end)
       ]
   in
   Provider.T { t; handler }
 ```
 
 ```ocaml
 # print (string_provider "Hello World")
-Hello World
+HELLO WORLD
 - : unit = ()
 ```

doc/docs/tutorials/getting-started/README.md

@@ -126,8 +126,14 @@ To use Provider, first we have to create a new tag and a new type constructor th
 ```ocaml
 type reader = [ `Reader ]
 
-type (_, _, _) Provider.Trait.t +=
-  Reader : ('t, (module READER with type t = 't), [> reader ]) Provider.Trait.t
+module Reader : sig
+  val t : ('t, (module READER with type t = 't), [> reader ]) Provider.Trait.t
+end = struct
+  type (_, _, _) Provider.Trait.t +=
+    Reader : ('t, (module READER with type t = 't), [> reader ]) Provider.Trait.t
+
+  let t = Reader
+end
 ```
 
 ### Parametrized Library
@@ -142,11 +148,11 @@ module Show_files2 : sig
 end = struct
 
   let print_files_with_ext (Provider.T { t = reader; handler }) ~path ~ext =
-    let module Reader = (val Provider.Handler.lookup handler ~trait:Reader) in
-    let entries = Reader.readdir reader ~path |> List.sort String.compare in
+    let module R = (val Provider.Handler.lookup handler ~trait:Reader.t) in
+    let entries = R.readdir reader ~path |> List.sort String.compare in
     let files = List.filter (String.ends_with ~suffix:ext) entries in
     files |> List.iter (fun file ->
-      let contents = Reader.load_file reader ~path:(Filename.concat path file) in
+      let contents = R.load_file reader ~path:(Filename.concat path file) in
       let line_count =
         List.length (String.split_on_char '\n' contents)
         - (if String.ends_with ~suffix:"\n" contents then 1 else 0)
@@ -168,8 +174,8 @@ module Show_files3 : sig
 end = struct
 
   let print_files_with_ext (Provider.T { t = reader; handler }) ~path ~ext =
-    let module Reader = (val Provider.Handler.lookup handler ~trait:Reader) in
-    let module M = Show_files (Reader) in
+    let module R = (val Provider.Handler.lookup handler ~trait:Reader.t) in
+    let module M = Show_files (R) in
     M.print_files_with_ext reader ~path ~ext
 
 end
@@ -187,7 +193,7 @@ let sys_reader () : [ `Reader ] Provider.t =
     { t = ()
     ; handler =
         Provider.Handler.make
-          [ Provider.Trait.implement Reader ~impl:(module Sys_reader) ]
+          [ Provider.Trait.implement Reader.t ~impl:(module Sys_reader) ]
     }
 ```
 

doc/docs/tutorials/handler-explicit/README.md

@@ -22,12 +22,18 @@ module type Id = sig type t val id : t -> t end
 
 type id = [ `Id ]
 
-type (_, _, _) Provider.Trait.t +=
-  | Id : ('a, (module Id with type t = 'a), [> id]) Provider.Trait.t
+module Id : sig
+  val t : ('a, (module Id with type t = 'a), [> id]) Provider.Trait.t
+end = struct
+  type (_, _, _) Provider.Trait.t +=
+    | Id : ('a, (module Id with type t = 'a), [> id]) Provider.Trait.t
+
+  let t = Id
+end
 
 let id : type a. (a, [> id]) Provider.Handler.t -> a -> a =
   fun handler x ->
-  let module M = (val Provider.Handler.lookup handler ~trait:Id) in
+  let module M = (val Provider.Handler.lookup handler ~trait:Id.t) in
   M.id x
 ;;
 ```
@@ -59,8 +65,15 @@ We define the expected *Provider* machinery, including a `Provider.Trait` for it
 ```ocaml
 type doublable = [ `Doublable ]
 
-type (_, _, _) Provider.Trait.t +=
-  | Doublable : ('a, (module Doublable with type t = 'a), [> doublable ]) Provider.Trait.t
+module Doublable : sig
+  val t : ('a, (module Doublable with type t = 'a), [> doublable ]) Provider.Trait.t
+end = struct
+
+  type (_, _, _) Provider.Trait.t +=
+    | Doublable : ('a, (module Doublable with type t = 'a), [> doublable ]) Provider.Trait.t
+
+  let t = Doublable
+end
 ```
 
 ### Writing Parametrized Code
@@ -70,7 +83,7 @@ With no dependencies on actual providers, we can define functionality depending
 ```ocaml
 # let quadruple : type a. (a, [> doublable ]) Provider.Handler.t -> a -> a =
   fun handler t ->
-  let module M = (val Provider.Handler.lookup handler ~trait:Doublable) in
+  let module M = (val Provider.Handler.lookup handler ~trait:Doublable.t) in
   M.double (M.double t)
 val quadruple : ('a, [> doublable ]) Provider.Handler.t -> 'a -> 'a = <fun>
 ```
@@ -98,12 +111,12 @@ We build *handlers* values for these modules:
 ```ocaml
 # let doublable_int () : (int, [> doublable ]) Provider.Handler.t =
   Provider.Handler.make
-    [ Provider.Trait.implement Doublable ~impl:(module Doublable_int) ]
+    [ Provider.Trait.implement Doublable.t ~impl:(module Doublable_int) ]
 val doublable_int : unit -> (int, [> doublable ]) Provider.Handler.t = <fun>
 
 # let doublable_float () : (float, [> doublable ]) Provider.Handler.t =
   Provider.Handler.make
-    [ Provider.Trait.implement Doublable ~impl:(module Doublable_float) ]
+    [ Provider.Trait.implement Doublable.t ~impl:(module Doublable_float) ]
 val doublable_float : unit -> (float, [> doublable ]) Provider.Handler.t =
   <fun>
 ```
@@ -137,8 +150,14 @@ end
 ```ocaml
 type repeatable = [ `Repeatable ]
 
-type (_, _, _) Provider.Trait.t +=
-  | Repeatable : ('a, (module Repeatable with type t = 'a), [> repeatable ]) Provider.Trait.t
+module Repeatable : sig
+  val t : ('a, (module Repeatable with type t = 'a), [> repeatable ]) Provider.Trait.t
+end = struct
+  type (_, _, _) Provider.Trait.t +=
+    | Repeatable : ('a, (module Repeatable with type t = 'a), [> repeatable ]) Provider.Trait.t
+
+  let t = Repeatable
+end
 ```
 
 ### Writing Parametrized Code
@@ -148,9 +167,9 @@ The function below requires both `repeatable` and `doublable` Traits:
 ```ocaml
 # let double_then_repeat : type a. (a, [> doublable | repeatable ]) Provider.Handler.t -> a -> a =
   fun handler t ->
-  let module D = (val Provider.Handler.lookup handler ~trait:Doublable) in
-  let module R = (val Provider.Handler.lookup handler ~trait:Repeatable) in
-  R.repeat (D.double t)
+  let module D = (val Provider.Handler.lookup handler ~trait:Doublable.t) in
+  let module R = (val Provider.Handler.lookup handler ~trait:Repeatable.t) in
+  t |> D.double |> R.repeat
 val double_then_repeat :
   ('a, [> `Doublable | `Repeatable ]) Provider.Handler.t -> 'a -> 'a = <fun>
 ```
@@ -174,8 +193,8 @@ We can now build a *handler* for it:
 ```ocaml
 # let versatile_int () : (int, [> doublable | repeatable ]) Provider.Handler.t =
   Provider.Handler.make
-    [ Provider.Trait.implement Doublable ~impl:(module Versatile_int)
-    ; Provider.Trait.implement Repeatable ~impl:(module Versatile_int)
+    [ Provider.Trait.implement Doublable.t ~impl:(module Versatile_int)
+    ; Provider.Trait.implement Repeatable.t ~impl:(module Versatile_int)
     ]
 val versatile_int :
   unit -> (int, [> `Doublable | `Repeatable ]) Provider.Handler.t = <fun>
@@ -247,23 +266,39 @@ type mappable = [ `Mappable ]
 Note, you cannot write this (the `'a 't` syntax doesn't mean anything):
 
 ```ocaml
-type (_, _, _) Provider.Trait.t +=
-  | Mappable : ('a 't, (module Mappable with type 'a t = 'a 't), [> mappable ]) Provider.Trait.t
+module Mappable : sig
+  val t : ('a 't, (module Mappable with type 'a t = 'a 't), [> mappable ]) Provider.Trait.t
+end = struct
+  type (_, _, _) Provider.Trait.t +=
+    | Mappable : ('a 't, (module Mappable with type 'a t = 'a 't), [> mappable ]) Provider.Trait.t
+
+  let t = Mappable
+end
 ```
 ```mdx-error
-Line 2, characters 22-23:
+Line 2, characters 17-18:
 Error: Syntax error
 ```
 
 This is where `Higher_kinded` comes to the rescue:
 
 ```ocaml
-type (_, _, _) Provider.Trait.t +=
-  | Mappable :
-      ( ('a -> 'higher_kinded) Higher_kinded.t
-        , (module Mappable with type higher_kinded = 'higher_kinded)
-        , [> mappable ] )
-        Provider.Trait.t
+module Mappable : sig
+  val t :
+       ( ('a -> 'higher_kinded) Higher_kinded.t
+          , (module Mappable with type higher_kinded = 'higher_kinded)
+          , [> mappable ] )
+          Provider.Trait.t
+end = struct
+  type (_, _, _) Provider.Trait.t +=
+    | Mappable :
+        ( ('a -> 'higher_kinded) Higher_kinded.t
+          , (module Mappable with type higher_kinded = 'higher_kinded)
+          , [> mappable ] )
+          Provider.Trait.t
+
+  let t = Mappable
+end
 ```
 
 ### Writing Parametrized Code
@@ -280,7 +315,7 @@ let map_n_times
     -> (a -> t) Higher_kinded.t
   =
   fun handler t n ~f ->
-  let module M = (val Provider.Handler.lookup handler ~trait:Mappable) in
+  let module M = (val Provider.Handler.lookup handler ~trait:Mappable.t) in
   let at = M.project t in
   let rec loop n at = if n = 0 then at else loop (n - 1) (M.map f at) in
   M.inject (loop n at)
@@ -321,7 +356,7 @@ We build *handlers* values for these modules:
       Provider.Handler.t
   =
   Provider.Handler.make
-    [ Provider.Trait.implement Mappable ~impl:(module Higher_kinded_list) ]
+    [ Provider.Trait.implement Mappable.t ~impl:(module Higher_kinded_list) ]
 val mappable_list :
   unit ->
   (('a -> Higher_kinded_list.higher_kinded) Higher_kinded.t, [> mappable ])
@@ -333,7 +368,7 @@ val mappable_list :
       Provider.Handler.t
   =
   Provider.Handler.make
-    [ Provider.Trait.implement Mappable ~impl:(module Higher_kinded_array) ]
+    [ Provider.Trait.implement Mappable.t ~impl:(module Higher_kinded_array) ]
 val mappable_array :
   unit ->
   (('a -> Higher_kinded_array.higher_kinded) Higher_kinded.t, [> mappable ])

test/eio/test__reader.ml

@@ -54,7 +54,7 @@ let print_all_text_files_with_lines_if_available t ~path =
         match
           Provider.Handler.lookup_opt
             handler
-            ~trait:Test_interfaces.File_reader.Provider_interface.File_reader
+            ~trait:Test_interfaces.File_reader.Provider_interface.file_reader
         with
         | None -> "not-available"
         | Some (module File_reader) ->

test/eio/test_providers/eio_reader.ml

@@ -17,10 +17,10 @@ let make ~env : [ `Directory_reader | `File_reader ] Provider.t =
     ; handler =
         Provider.Handler.make
           [ Provider.Trait.implement
-              Test_interfaces.Directory_reader.Provider_interface.Directory_reader
+              Test_interfaces.Directory_reader.Provider_interface.directory_reader
               ~impl:(module Impl)
           ; Provider.Trait.implement
-              Test_interfaces.File_reader.Provider_interface.File_reader
+              Test_interfaces.File_reader.Provider_interface.file_reader
               ~impl:(module Impl)
           ]
     }

test/test__cache.ml

@@ -17,11 +17,11 @@ let%expect_test "override" =
   let cache_state_of_uid uid =
     if Provider.Trait.Uid.equal
          uid
-         (Test_interfaces.Int_printer.Provider_interface.Int_printer |> Provider.Trait.uid)
+         (Test_interfaces.Int_printer.Provider_interface.int_printer |> Provider.Trait.uid)
     then Cache_state.Int_printer
     else if Provider.Trait.Uid.equal
               uid
-              (Test_interfaces.Float_printer.Provider_interface.Float_printer
+              (Test_interfaces.Float_printer.Provider_interface.float_printer
                |> Provider.Trait.uid)
     then Cache_state.Float_printer
     else assert false [@coverage off]
@@ -45,7 +45,7 @@ let%expect_test "override" =
       ignore
         (Provider.Handler.lookup
            handler
-           ~trait:Test_interfaces.Int_printer.Provider_interface.Int_printer
+           ~trait:Test_interfaces.Int_printer.Provider_interface.int_printer
          : (module Test_interfaces.Int_printer.Provider_interface.S with type t = a)))
       handler;
     require_equal
@@ -59,7 +59,7 @@ let%expect_test "override" =
       ignore
         (Provider.Handler.lookup
            handler
-           ~trait:Test_interfaces.Float_printer.Provider_interface.Float_printer
+           ~trait:Test_interfaces.Float_printer.Provider_interface.float_printer
          : (module Test_interfaces.Float_printer.Provider_interface.S with type t = a)))
       handler;
     require_equal
@@ -74,7 +74,7 @@ let%expect_test "override" =
       (Option.is_some
          (Provider.Handler.lookup_opt
             handler
-            ~trait:Test_interfaces.Int_printer.Provider_interface.Int_printer));
+            ~trait:Test_interfaces.Int_printer.Provider_interface.int_printer));
     require_equal
       [%here]
       (module Cache_state)
@@ -87,7 +87,7 @@ let%expect_test "override" =
       (Option.is_some
          (Provider.Handler.lookup_opt
             handler
-            ~trait:Test_interfaces.Float_printer.Provider_interface.Float_printer));
+            ~trait:Test_interfaces.Float_printer.Provider_interface.float_printer));
     require_equal
       [%here]
       (module Cache_state)
@@ -100,7 +100,7 @@ let%expect_test "override" =
       [%here]
       (Provider.Handler.implements
          handler
-         ~trait:Test_interfaces.Int_printer.Provider_interface.Int_printer);
+         ~trait:Test_interfaces.Int_printer.Provider_interface.int_printer);
     let post_cache_state = cache_state handler in
     require_equal [%here] (module Cache_state) pre_cache_state post_cache_state
   in
@@ -110,7 +110,7 @@ let%expect_test "override" =
       [%here]
       (Provider.Handler.implements
          handler
-         ~trait:Test_interfaces.Float_printer.Provider_interface.Float_printer);
+         ~trait:Test_interfaces.Float_printer.Provider_interface.float_printer);
     let post_cache_state = cache_state handler in
     require_equal [%here] (module Cache_state) pre_cache_state post_cache_state
   in