Add ocp-indent as a formatter

CHANGELOG.md

@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog].
 * New user option `apheleia-skip-functions`, like
   `apheleia-inhibit-functions` but for skipping a formatter run even
   when `apheleia-mode` is generally enabled ([#317]).
+* [`ocp-indent`](https://github.com/OCamlPro/ocp-indent) for
+  [Ocaml](https://ocaml.org/) ([#306]).
 
 ### Formatters
 * [`typstyle`](https://github.com/Enter-tainer/typstyle) for

apheleia-formatters.el

@@ -95,6 +95,7 @@
     (nixfmt . ("nixfmt"))
     (ocamlformat . ("ocamlformat" "-" "--name" filepath
                     "--enable-outside-detected-project"))
+    (ocp-indent . ("ocp-indent"))
     (ormolu . ("ormolu"))
     (perltidy . ("perltidy" "--quiet" "--standard-error-output"
                  (apheleia-formatters-indent "-t" "-i")

test/formatters/installers/ocp-indent.bash

@@ -0,0 +1,5 @@
+apt-get install -y opam
+
+opam init -n --disable-sandboxing --root /opt/ocp-indent
+opam install ocp-indent -y --root /opt/ocp-indent
+ln -s /opt/ocp-indent/default/bin/ocp-indent /usr/local/bin/

test/formatters/samplecode/ocp-indent/in.ml

@@ -0,0 +1,35 @@
+(* https://github.com/OCamlPro/ocp-indent/blob/master/tests/failing/list_of_funs.ml *)
+
+let f x =
+  (fun x -> x [ (fun () -> 3) ;
+                (fun () -> 4) ])
+
+let f x = (fun x -> x [ (fun () -> 3) ;
+                        (fun () -> 4) ])
+
+let f x =
+  x [ (fun () -> 3) ;
+      (fun () -> 4) ]
+
+let f x =
+  [ (fun () -> 3) ;
+    (fun () -> 4) ]
+
+let f x =
+  (fun x -> x [ (fun () ->
+                   3) ;
+                (fun () -> 4) ])
+
+let f x = (fun x -> x [ (fun () ->
+                           3) ;
+                        (fun () -> 4) ])
+
+let f x =
+  x [ (fun () ->
+         3) ;
+      (fun () -> 4) ]
+
+let f x =
+  [ (fun () ->
+       3) ;
+    (fun () -> 4) ]

test/formatters/samplecode/ocp-indent/out.ml

@@ -0,0 +1,35 @@
+(* https://github.com/OCamlPro/ocp-indent/blob/master/tests/failing/list_of_funs.ml *)
+
+let f x =
+  (fun x -> x [ (fun () -> 3) ;
+                (fun () -> 4) ])
+
+let f x = (fun x -> x [ (fun () -> 3) ;
+                        (fun () -> 4) ])
+
+let f x =
+  x [ (fun () -> 3) ;
+      (fun () -> 4) ]
+
+let f x =
+  [ (fun () -> 3) ;
+    (fun () -> 4) ]
+
+let f x =
+  (fun x -> x [ (fun () ->
+       3) ;
+       (fun () -> 4) ])
+
+let f x = (fun x -> x [ (fun () ->
+    3) ;
+    (fun () -> 4) ])
+
+let f x =
+  x [ (fun () ->
+      3) ;
+      (fun () -> 4) ]
+
+let f x =
+  [ (fun () ->
+        3) ;
+    (fun () -> 4) ]