Expose let_binding_deindent_fun flag (#2521)

CHANGES.md

@@ -8,6 +8,7 @@ profile. This started with version 0.26.0.
 
 ### Changed
 
+- Added `let-binding-deindent-fun` flag (#2521, @henrytill)
 - Added back the flag `--disable-outside-detected-project` (#2439, @gpetiot)
   It was removed in version 0.22.
 - \* Consistent formatting of comments (#2371, @Julow)

doc/manpage_ocamlformat.mld

@@ -248,6 +248,9 @@ OPTIONS (CODE FORMATTING STYLE)
            in a single line. sparse will always break between them. The
            default value is compact.
 
+       --let-binding-deindent-fun
+           Deindent a line beginning with `fun`. The flag is set by default.
+
        --let-binding-indent=COLS
            Indentation of let binding expressions (COLS columns) if they do
            not fit on a single line. The default value is 2. Cannot be set in
@@ -321,6 +324,9 @@ OPTIONS (CODE FORMATTING STYLE)
        --no-leading-nested-match-parens
            Unset leading-nested-match-parens.
 
+       --no-let-binding-deindent-fun
+           Unset let-binding-deindent-fun.
+
        --no-ocp-indent-compat
            Unset ocp-indent-compat.
 

lib/Conf.ml

@@ -953,6 +953,14 @@ module Formatting = struct
         update conf ~f:(fun f -> {f with let_binding_indent= elt}) )
       (fun conf -> conf.fmt_opts.let_binding_indent)
 
+  let let_binding_deindent_fun =
+    let doc = "Deindent a line beginning with `fun`." in
+    let names = ["let-binding-deindent-fun"] in
+    Decl.flag ~names ~default ~doc ~kind
+      (fun conf elt ->
+        update conf ~f:(fun f -> {f with let_binding_deindent_fun= elt}) )
+      (fun conf -> conf.fmt_opts.let_binding_deindent_fun)
+
   let let_binding_spacing =
     let doc = "Spacing between let binding." in
     let names = ["let-binding-spacing"] in
@@ -1334,6 +1342,7 @@ module Formatting = struct
       ; elt leading_nested_match_parens
       ; elt let_and
       ; elt let_binding_indent
+      ; elt let_binding_deindent_fun
       ; elt let_binding_spacing
       ; elt let_module
       ; elt line_endings

test/cli/print_config.t

@@ -55,6 +55,7 @@ No redundant values:
   leading-nested-match-parens=false (profile conventional (file .ocamlformat:1))
   let-and=compact (profile conventional (file .ocamlformat:1))
   let-binding-indent=2 (profile conventional (file .ocamlformat:1))
+  let-binding-deindent-fun=true (profile conventional (file .ocamlformat:1))
   let-binding-spacing=compact (profile conventional (file .ocamlformat:1))
   let-module=compact (profile conventional (file .ocamlformat:1))
   line-endings=lf (profile conventional (file .ocamlformat:1))
@@ -133,6 +134,7 @@ Redundant values from the conventional profile:
   leading-nested-match-parens=false (profile conventional (file .ocamlformat:1))
   let-and=compact (profile conventional (file .ocamlformat:1))
   let-binding-indent=2 (profile conventional (file .ocamlformat:1))
+  let-binding-deindent-fun=true (profile conventional (file .ocamlformat:1))
   let-binding-spacing=compact (profile conventional (file .ocamlformat:1))
   let-module=compact (profile conventional (file .ocamlformat:1))
   line-endings=lf (profile conventional (file .ocamlformat:1))
@@ -211,6 +213,7 @@ Redundant values from the ocamlformat profile:
   leading-nested-match-parens=false (profile ocamlformat (file .ocamlformat:1))
   let-and=compact (profile ocamlformat (file .ocamlformat:1))
   let-binding-indent=2 (profile ocamlformat (file .ocamlformat:1))
+  let-binding-deindent-fun=true (profile ocamlformat (file .ocamlformat:1))
   let-binding-spacing=compact (profile ocamlformat (file .ocamlformat:1))
   let-module=compact (profile ocamlformat (file .ocamlformat:1))
   line-endings=lf (profile ocamlformat (file .ocamlformat:1))

test/passing/tests/print_config.ml.err

@@ -40,6 +40,7 @@ infix-precedence=indent (profile ocamlformat (file tests/.ocamlformat:1))
 leading-nested-match-parens=false (profile ocamlformat (file tests/.ocamlformat:1))
 let-and=compact (profile ocamlformat (file tests/.ocamlformat:1))
 let-binding-indent=2 (profile ocamlformat (file tests/.ocamlformat:1))
+let-binding-deindent-fun=true (profile ocamlformat (file tests/.ocamlformat:1))
 let-binding-spacing=compact (profile ocamlformat (file tests/.ocamlformat:1))
 let-module=compact (profile ocamlformat (file tests/.ocamlformat:1))
 line-endings=lf (profile ocamlformat (file tests/.ocamlformat:1))

test/passing/tests/verbose1.ml.err

@@ -40,6 +40,7 @@ infix-precedence=indent (profile ocamlformat (file tests/.ocamlformat:1))
 leading-nested-match-parens=false (profile ocamlformat (file tests/.ocamlformat:1))
 let-and=compact (profile ocamlformat (file tests/.ocamlformat:1))
 let-binding-indent=2 (profile ocamlformat (file tests/.ocamlformat:1))
+let-binding-deindent-fun=true (profile ocamlformat (file tests/.ocamlformat:1))
 let-binding-spacing=compact (profile ocamlformat (file tests/.ocamlformat:1))
 let-module=compact (profile ocamlformat (file tests/.ocamlformat:1))
 line-endings=lf (profile ocamlformat (file tests/.ocamlformat:1))