Remove incorrect fmt_expression ~epi mechanism (#2445)

This argument doesn't work similarly to the `~epi` argument of other
functions. It meant different things depending on the expression:

- `Pexp_match` and `Pexp_apply`: it was similar to `~pro`.
- `Pexp_constant`: like the usual `~epi` but was passed a break.
- all other cases: it was not used.

These rules are now handled in `fmt_args_grouped`, the only place where
they made sense. The `~epi` argument is removed.

In the first case, the `~pro` argument is used instead. This requires
refactoring `fmt_expression` to make sure that every cases use `~pro`
exactly once.

CHANGES.md

@@ -16,6 +16,7 @@ profile. This started with version 0.26.0.
 - Remove trailing space inside a wrapping empty signature (#2443, @Julow)
 - Fix extension-point spacing in structures (#2450, @Julow)
 - \* Consistent break after string constant argument (#2453, @Julow)
+- Fix invalid syntax generated with `ocp-indent-compat` (#2445, @Julow)
 
 ## 0.26.1 (2023-09-15)
 

test/passing/dune.inc

@@ -4114,13 +4114,31 @@
  (package ocamlformat)
  (action (diff tests/obuild.ml.err obuild.ml.stderr)))
 
+(rule
+ (deps tests/.ocamlformat )
+ (package ocamlformat)
+ (action
+  (with-stdout-to ocp_indent_compat-break_colon_after.ml.stdout
+   (with-stderr-to ocp_indent_compat-break_colon_after.ml.stderr
+     (run %{bin:ocamlformat} --margin-check --ocp-indent-compat --break-colon=after %{dep:tests/ocp_indent_compat.ml})))))
+
+(rule
+ (alias runtest)
+ (package ocamlformat)
+ (action (diff tests/ocp_indent_compat-break_colon_after.ml.ref ocp_indent_compat-break_colon_after.ml.stdout)))
+
+(rule
+ (alias runtest)
+ (package ocamlformat)
+ (action (diff tests/ocp_indent_compat-break_colon_after.ml.err ocp_indent_compat-break_colon_after.ml.stderr)))
+
 (rule
  (deps tests/.ocamlformat )
  (package ocamlformat)
  (action
   (with-stdout-to ocp_indent_compat.ml.stdout
    (with-stderr-to ocp_indent_compat.ml.stderr
-     (run %{bin:ocamlformat} --margin-check %{dep:tests/ocp_indent_compat.ml})))))
+     (run %{bin:ocamlformat} --margin-check --ocp-indent-compat --break-colon=before %{dep:tests/ocp_indent_compat.ml})))))
 
 (rule
  (alias runtest)

test/passing/tests/ocp_indent_compat-break_colon_after.ml.opts

@@ -0,0 +1,2 @@
+--ocp-indent-compat
+--break-colon=after

test/passing/tests/ocp_indent_compat-break_colon_after.ml.ref

@@ -0,0 +1,93 @@
+(* Bad: unboxing the function type *)
+external i : (int -> float[@unboxed]) = "i" "i_nat"
+
+module type M = sig
+  val action : action
+  (** Formatting action: input type and source, and output destination. *)
+
+  val doc_atrs :
+     (string Location.loc * payload) list
+    -> (string Location.loc * bool) list option
+       * (string Location.loc * payload) list
+
+  val transl_modtype_longident
+    (* from Typemod *) :
+    (Location.t -> Env.t -> Longident.t -> Path.t) ref
+
+  val transl_modtype_longident
+    (* foooooooooo fooooooooooooo foooooooooooo foooooooooooooo
+       foooooooooooooo foooooooooooo *) :
+    (Location.t -> Env.t -> Longident.t -> Path.t) ref
+
+  val imported_sets_of_closures_table :
+    Simple_value_approx.function_declarations option Set_of_closures_id.Tbl.t
+
+  type 'a option_decl =
+    names:string list
+    -> doc:string
+    -> section:[`Formatting | `Operational]
+    -> ?allow_inline:bool
+    -> (config -> 'a -> config)
+    -> (config -> 'a)
+    -> 'a t
+
+  val select :
+     (* The fsevents context *)
+     env
+    -> (* Additional file descriptor to select for reading *)
+       ?read_fdl:fd_select list
+    -> (* Additional file descriptor to select for writing *)
+       ?write_fdl:fd_select list
+    -> (* Timeout...like Unix.select *)
+       timeout:float
+    -> (* The callback for file system events *)
+       (event list -> unit)
+    -> unit
+
+  val f :
+     x:t
+       (** an extremely long comment about [x] that does not fit on the same
+           line with [x] *)
+    -> unit
+
+  val f :
+     fooooooooooooooooo:
+       (fooooooooooooooo
+        -> fooooooooooooooooooo
+        -> foooooooooooooo
+        -> foooooooooooooo * fooooooooooooooooo
+        -> foooooooooooooooo )
+       (** an extremely long comment about [x] that does not fit on the same
+           line with [x] *)
+    -> unit
+end
+
+let ssmap :
+    (module MapT
+       with type key = string
+        and type data = string
+        and type map = SSMap.map )
+  =
+  ()
+
+let ssmap :
+     (module MapT
+        with type key = string
+         and type data = string
+         and type map = SSMap.map )
+    -> unit
+  =
+  ()
+
+let long_function_name :
+    type a. a long_long_type -> a -> a -> a -> wrap_wrap_wrap -> unit
+  =
+ fun () -> ()
+
+let add_edge target dep =
+  if target <> dep then (
+    Hashtbl.replace edges dep
+      (target :: (try Hashtbl.find edges dep with Not_found -> [])) ;
+    Hashtbl.replace edge_count target
+      (1 + try Hashtbl.find edge_count target with Not_found -> 0) ;
+    if not (Hashtbl.mem edge_count dep) then Hashtbl.add edge_count dep 0 )

test/passing/tests/ocp_indent_compat.ml

@@ -1,7 +1,3 @@
-[@@@ocamlformat "ocp-indent-compat=true"]
-
-[@@@ocamlformat "break-colon=before"]
-
 (* Bad: unboxing the function type *)
 external i : (int -> float[@unboxed]) = "i" "i_nat"
 
@@ -89,64 +85,10 @@ let long_function_name
   =
  fun () -> ()
 
-[@@@ocamlformat "ocp-indent-compat=false"]
-
-[@@@ocamlformat "break-colon=after"]
-
-module type M = sig
-  val transl_modtype_longident (* from Typemod *) :
-    (Location.t -> Env.t -> Longident.t -> Path.t) ref
-
-  val transl_modtype_longident
-    (* foooooooooo fooooooooooooo foooooooooooo foooooooooooooo
-       foooooooooooooo foooooooooooo *) :
-    (Location.t -> Env.t -> Longident.t -> Path.t) ref
-
-  val imported_sets_of_closures_table :
-    Simple_value_approx.function_declarations option Set_of_closures_id.Tbl.t
-
-  val select :
-       (* The fsevents context *)
-       env
-    -> (* Additional file descriptor to select for reading *)
-       ?read_fdl:fd_select list
-    -> (* Additional file descriptor to select for writing *)
-       ?write_fdl:fd_select list
-    -> (* Timeout...like Unix.select *)
-       timeout:float
-    -> (* The callback for file system events *)
-       (event list -> unit)
-    -> unit
-
-  val f :
-       x:t
-         (** an extremely long comment about [x] that does not fit on the
-             same line with [x] *)
-    -> unit
-
-  val f :
-       fooooooooooooooooo:
-         (   fooooooooooooooo
-          -> fooooooooooooooooooo
-          -> foooooooooooooo
-          -> foooooooooooooo * fooooooooooooooooo
-          -> foooooooooooooooo )
-         (** an extremely long comment about [x] that does not fit on the
-             same line with [x] *)
-    -> unit
-end
-
-let array_fold_transf (f : numbering -> 'a -> numbering * 'b) n (a : 'a array)
-    : numbering * 'b array =
-  match Array.length a with 0 -> (n, [||]) | 1 -> x
-
-let to_clambda_function (id, (function_decl : Flambda.function_declaration))
-    : Clambda.ufunction =
-  (* All that we need in the environment, for translating one closure from a
-     closed set of closures, is the substitutions for variables bound to the
-     various closures in the set. Such closures will always be ... *)
-  x
-
-let long_function_name :
-    type a. a long_long_type -> a -> a -> a -> wrap_wrap_wrap -> unit =
- fun () -> ()
+let add_edge target dep =
+  if target <> dep then (
+    Hashtbl.replace edges dep
+      (target :: (try Hashtbl.find edges dep with Not_found -> [])) ;
+    Hashtbl.replace edge_count target
+      (1 + try Hashtbl.find edge_count target with Not_found -> 0) ;
+    if not (Hashtbl.mem edge_count dep) then Hashtbl.add edge_count dep 0 )

test/passing/tests/ocp_indent_compat.ml.err

@@ -1 +0,0 @@
-Warning: tests/ocp_indent_compat.ml:138 exceeds the margin

test/passing/tests/ocp_indent_compat.ml.opts

@@ -0,0 +1,2 @@
+--ocp-indent-compat
+--break-colon=before