basic code

src/lib/format_sail.ml

@@ -440,6 +440,27 @@ module type CONFIG = sig
   val config : config
 end
 
+let rec can_shrink_to_oneline cqs =
+  match cqs with
+  | [] -> true
+  | [cq] -> (
+      match List.of_seq (Queue.to_seq cq) with
+      | [] -> true
+      | [c] -> (
+          match c with
+          (* Atom is ok *)
+          | Atom _ -> true
+          (* {{{ Atom }}} is ok *)
+          | Block (_, exps) -> can_shrink_to_oneline exps
+          | If_then_else (_, i, t, e) -> can_shrink_to_oneline [t; e]
+          | _ -> false
+        )
+      | c :: cq ->
+          can_shrink_to_oneline [Queue.of_seq (List.to_seq [c])]
+          && can_shrink_to_oneline [Queue.of_seq (List.to_seq cq)]
+    )
+  | cq :: cqs -> can_shrink_to_oneline [cq] && can_shrink_to_oneline cqs
+
 module Make (Config : CONFIG) = struct
   let indent = Config.config.indent
   let preserve_structure = Config.config.preserve_structure
@@ -636,14 +657,20 @@ module Make (Config : CONFIG) = struct
              )
     | Pragma (pragma, arg) -> char '$' ^^ string pragma ^^ space ^^ string arg ^^ hardline
     | Block (always_hardline, exps) ->
+        let always_hardline, indent, padding =
+          match exps with
+          | x :: [xs] -> (always_hardline, indent, 1)
+          | [x] -> if can_shrink_to_oneline exps then (false, 4, 1) else (always_hardline, indent, 1)
+          | _ -> (always_hardline, indent, 1)
+        in
         let exps =
           map_last
             (fun no_semi chunks -> doc_block_exp_chunks (opts |> nonatomic |> statement_like) no_semi chunks)
             exps
         in
         let sep = if always_hardline || List.exists snd exps then hardline else break 1 in
         let exps = List.map fst exps in
-        surround_hardline always_hardline indent 1 (char '{') (separate sep exps) (char '}') |> atomic_parens opts
+        surround_hardline always_hardline indent padding (char '{') (separate sep exps) (char '}') |> atomic_parens opts
     | Block_binder (binder, x, y) ->
         if can_hang y then
           separate space

test/format/default/function_quant.expect

@@ -3,24 +3,16 @@ default Order dec
 $include <prelude.sail>
 
 function foo forall 'n 'm, 'n >= 0.
-(x : int('n), y : int('m)) -> unit = {
-    ()
-}
+(x : int('n), y : int('m)) -> unit = { () }
 
 function foo /* c */ forall 'n 'm, 'n >= 0.
-(x : int('n), y : int('m)) -> unit = {
-    ()
-}
+(x : int('n), y : int('m)) -> unit = { () }
 
 function foo forall /* c */ 'n 'm, 'n >= 0.
-(x : int('n), y : int('m)) -> unit = {
-    ()
-}
+(x : int('n), y : int('m)) -> unit = { () }
 
 function foo forall 'n 'm, /* c */ 'n >= 0.
-(x : int('n), y : int('m)) -> unit = {
-    ()
-}
+(x : int('n), y : int('m)) -> unit = { () }
 
 function foo forall 'very_long_identifier_that_will_cause_a_line_break 'm, 'n >= 0.
 (x : int('very_long_identifier_that_will_cause_a_line_break), y : int('m)) -> unit = {

test/format/default/function_quant.sail

@@ -0,0 +1,18 @@
+default Order dec
+
+$include <prelude.sail>
+
+function foo forall 'n 'm, 'n >= 0.
+(x : int('n), y : int('m)) -> unit = { () }
+
+function foo /* c */ forall 'n 'm, 'n >= 0.
+(x : int('n), y : int('m)) -> unit = { () }
+
+function foo forall /* c */ 'n 'm, 'n >= 0.
+(x : int('n), y : int('m)) -> unit = { () }
+
+function foo forall 'n 'm, /* c */ 'n >= 0.
+(x : int('n), y : int('m)) -> unit = { () }
+
+function foo forall 'very_long_identifier_that_will_cause_a_line_break 'm, 'n >= 0.
+(x : int('very_long_identifier_that_will_cause_a_line_break), y : int('m)) -> unit = { () }

test/format/default/struct_update.expect

@@ -44,22 +44,14 @@ enum E with f -> very_long_type_that_will_trigger_a_linebreak,
 }
 
 function has_loops () = {
-    foreach (n from 1 to 3) {
-        ()
-    };
-    foreach (n from 3 downto 1) {
-        ()
-    };
-    foreach (n from 0 to 4 by 2) {
-        ()
-    };
+    foreach (n from 1 to 3) { () };
+    foreach (n from 3 downto 1) { () };
+    foreach (n from 0 to 4 by 2) { () };
     foreach (n from 10000000000000000000000000000000 to 444444444444444444444444444444444444444444444444444444444444) {
         ()
     };
     while true do ();
-    while true do {
-        ()
-    };
+    while true do { () };
     repeat termination_measure { foo } () until true
 }