New value 'vertical' for option 'if-then-else'

CHANGES.md

@@ -27,6 +27,7 @@
 
 - Add a `break-colon` option to decide whether to break before or after the `:` symbol in value binding declarations and type constraints. This behavior is no longer ensured by `ocp-indent-compat`. (#2149, @gpetiot)
 - Format `.mld` files as odoc documentation files (#2008, @gpetiot)
+- New value `vertical` for option `if-then-else` (#2174, @gpetiot)
 
 ## 0.24.1 (2022-07-18)
 

lib/Conf.ml

@@ -40,7 +40,8 @@ type fmt_opts =
   ; field_space: [`Tight | `Loose | `Tight_decl]
   ; function_indent: int
   ; function_indent_nested: [`Always | `Auto | `Never]
-  ; if_then_else: [`Compact | `Fit_or_vertical | `Keyword_first | `K_R]
+  ; if_then_else:
+      [`Compact | `Fit_or_vertical | `Vertical | `Keyword_first | `K_R]
   ; indent_after_in: int
   ; indicate_multiline_delimiters: [`No | `Space | `Closing_on_separate_line]
   ; indicate_nested_or_patterns: [`Space | `Unsafe_no]
@@ -662,6 +663,8 @@ module Formatting = struct
       ; C.Value.make ~name:"fit-or-vertical" `Fit_or_vertical
           "$(b,fit-or-vertical) vertically breaks branches if they do not \
            fit on a single line."
+      ; C.Value.make ~name:"vertical" `Vertical
+          "$(b,vertical) always vertically breaks branches."
       ; C.Value.make ~name:"keyword-first" `Keyword_first
           "$(b,keyword-first) formats if-then-else expressions such that \
            the if-then-else keywords are the first on the line."

lib/Conf.mli

@@ -40,7 +40,8 @@ type fmt_opts =
   ; field_space: [`Tight | `Loose | `Tight_decl]
   ; function_indent: int
   ; function_indent_nested: [`Always | `Auto | `Never]
-  ; if_then_else: [`Compact | `Fit_or_vertical | `Keyword_first | `K_R]
+  ; if_then_else:
+      [`Compact | `Fit_or_vertical | `Vertical | `Keyword_first | `K_R]
   ; indent_after_in: int
   ; indicate_multiline_delimiters: [`No | `Space | `Closing_on_separate_line]
   ; indicate_nested_or_patterns: [`Space | `Unsafe_no]

lib/Fmt_ast.ml

@@ -2133,7 +2133,7 @@ and fmt_expression c ?(box = true) ?pro ?epi ?eol ?parens ?(indent_wrap = 0)
                    $ p.box_keyword_and_expr
                        ( p.branch_pro
                        $ p.wrap_parens
-                           ( fmt_expression c ~box:false
+                           ( fmt_expression c ?box:p.box_expr
                                ~parens:symbol_parens ?pro:p.expr_pro
                                ?eol:p.expr_eol xbch
                            $ p.break_end_branch ) ) )

lib/Params.ml

@@ -321,6 +321,7 @@ type if_then_else =
   ; box_keyword_and_expr: Fmt.t -> Fmt.t
   ; branch_pro: Fmt.t
   ; wrap_parens: Fmt.t -> Fmt.t
+  ; box_expr: bool option
   ; expr_pro: Fmt.t option
   ; expr_eol: Fmt.t option
   ; break_end_branch: Fmt.t
@@ -385,6 +386,7 @@ let get_if_then_else (c : Conf.t) ~first ~last ~parens ~parens_bch
               (get_parens_breaks
                  ~opn_hint:((1, 0), (0, 0))
                  ~cls_hint:((1, 0), (1000, -2)) )
+      ; box_expr= Some false
       ; expr_pro= None
       ; expr_eol= None
       ; break_end_branch= noop
@@ -395,6 +397,7 @@ let get_if_then_else (c : Conf.t) ~first ~last ~parens ~parens_bch
       ; box_keyword_and_expr= Fn.id
       ; branch_pro
       ; wrap_parens= wrap_parens ~wrap_breaks:(wrap_k (break 1000 2) noop)
+      ; box_expr= Some false
       ; expr_pro= None
       ; expr_eol= Some (fmt "@;<1 2>")
       ; break_end_branch=
@@ -415,6 +418,7 @@ let get_if_then_else (c : Conf.t) ~first ~last ~parens ~parens_bch
               (get_parens_breaks
                  ~opn_hint:((1, 2), (0, 2))
                  ~cls_hint:((1, 0), (1000, 0)) )
+      ; box_expr= Some false
       ; expr_pro=
           Some
             (fmt_if_k
@@ -427,6 +431,26 @@ let get_if_then_else (c : Conf.t) ~first ~last ~parens ~parens_bch
             ( match imd with
             | `Closing_on_separate_line when beginend || parens_bch -> " "
             | _ -> "@ " ) }
+  | `Vertical ->
+      { box_branch= Fn.id
+      ; cond= cond ()
+      ; box_keyword_and_expr= Fn.id
+      ; branch_pro
+      ; wrap_parens=
+          wrap_parens
+            ~wrap_breaks:
+              (get_parens_breaks
+                 ~opn_hint:((1, 2), (0, 2))
+                 ~cls_hint:((1, 0), (1000, 0)) )
+      ; box_expr= None
+      ; expr_pro= Some (break_unless_newline 1000 2)
+      ; expr_eol= None
+      ; break_end_branch= noop
+      ; space_between_branches=
+          fmt
+            ( match imd with
+            | `Closing_on_separate_line when parens_bch -> " "
+            | _ -> "@ " ) }
   | `Keyword_first ->
       { box_branch= Fn.id
       ; cond=
@@ -448,6 +472,7 @@ let get_if_then_else (c : Conf.t) ~first ~last ~parens ~parens_bch
               (get_parens_breaks
                  ~opn_hint:((1, 0), (0, 0))
                  ~cls_hint:((1, 0), (1000, -2)) )
+      ; box_expr= Some false
       ; expr_pro= None
       ; expr_eol= None
       ; break_end_branch= noop

lib/Params.mli

@@ -101,6 +101,7 @@ type if_then_else =
   ; box_keyword_and_expr: Fmt.t -> Fmt.t
   ; branch_pro: Fmt.t
   ; wrap_parens: Fmt.t -> Fmt.t
+  ; box_expr: bool option
   ; expr_pro: Fmt.t option
   ; expr_eol: Fmt.t option
   ; break_end_branch: Fmt.t

ocamlformat-help.txt

@@ -195,14 +195,14 @@ OPTIONS (CODE FORMATTING STYLE)
            block starts a line. always always apply function-indent. auto
            applies function-indent when seen fit. The default value is never.
 
-       --if-then-else={compact|fit-or-vertical|keyword-first|k-r}
+       --if-then-else={compact|fit-or-vertical|vertical|keyword-first|k-r}
            If-then-else formatting. compact tries to format an if-then-else
            expression on a single line. fit-or-vertical vertically breaks
-           branches if they do not fit on a single line. keyword-first
-           formats if-then-else expressions such that the if-then-else
-           keywords are the first on the line. k-r formats if-then-else
-           expressions with parentheses that match the K&R style. The default
-           value is compact.
+           branches if they do not fit on a single line. vertical always
+           vertically breaks branches. keyword-first formats if-then-else
+           expressions such that the if-then-else keywords are the first on
+           the line. k-r formats if-then-else expressions with parentheses
+           that match the K&R style. The default value is compact.
 
        --indent-after-in=COLS
            Indentation (COLS columns) after `let ... in`, unless followed by

test/passing/dune.inc

@@ -2834,6 +2834,24 @@
  (package ocamlformat)
  (action (diff tests/ite-no_indicate.ml.err ite-no_indicate.ml.stderr)))
 
+(rule
+ (deps tests/.ocamlformat )
+ (package ocamlformat)
+ (action
+  (with-stdout-to ite-vertical.ml.stdout
+   (with-stderr-to ite-vertical.ml.stderr
+     (run %{bin:ocamlformat} --margin-check --if-then-else=vertical %{dep:tests/ite.ml})))))
+
+(rule
+ (alias runtest)
+ (package ocamlformat)
+ (action (diff tests/ite-vertical.ml.ref ite-vertical.ml.stdout)))
+
+(rule
+ (alias runtest)
+ (package ocamlformat)
+ (action (diff tests/ite-vertical.ml.err ite-vertical.ml.stderr)))
+
 (rule
  (deps tests/.ocamlformat )
  (package ocamlformat)

test/passing/tests/ite-compact.ml.ref

@@ -130,3 +130,9 @@ let _ =
   else if bar then ( * )
   else if foobar then ( / )
   else ( - )
+
+let _ =
+  if x then fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-compact_closing.ml.ref

@@ -145,3 +145,9 @@ let _ =
   else if bar then ( * )
   else if foobar then ( / )
   else ( - )
+
+let _ =
+  if x then fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-fit_or_vertical.ml.ref

@@ -159,3 +159,11 @@ let _ =
     ( / )
   else
     ( - )
+
+let _ =
+  if x then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-fit_or_vertical_closing.ml.ref

@@ -171,3 +171,11 @@ let _ =
     ( / )
   else
     ( - )
+
+let _ =
+  if x then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-fit_or_vertical_no_indicate.ml.ref

@@ -159,3 +159,11 @@ let _ =
     ( / )
   else
     ( - )
+
+let _ =
+  if x then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-kr.ml.ref

@@ -193,3 +193,11 @@ let _ =
     ( / )
   else
     ( - )
+
+let _ =
+  if x then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-kr_closing.ml.ref

@@ -203,3 +203,11 @@ let _ =
     ( / )
   else
     ( - )
+
+let _ =
+  if x then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+  xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-kw_first.ml.ref

@@ -151,3 +151,12 @@ let _ =
   else if foobar
   then ( / )
   else ( - )
+
+let _ =
+  if x
+  then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-kw_first_closing.ml.ref

@@ -166,3 +166,12 @@ let _ =
   else if foobar
   then ( / )
   else ( - )
+
+let _ =
+  if x
+  then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-kw_first_no_indicate.ml.ref

@@ -150,3 +150,12 @@ let _ =
   else if foobar
   then ( / )
   else ( - )
+
+let _ =
+  if x
+  then
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else
+    fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-no_indicate.ml.ref

@@ -129,3 +129,9 @@ let _ =
   else if bar then ( * )
   else if foobar then ( / )
   else ( - )
+
+let _ =
+  if x then fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz
+  else fun xxxxxxxxxxxxxxxxx yyyyyyyyyyyyyyyyyyyy zzzzzzzzzzz ->
+    xxxxxxxxx yyyyyyyyyy zzzzzzzzzzzz

test/passing/tests/ite-vertical.ml.opts

@@ -0,0 +1 @@
+--if-then-else=vertical