Uncurried types: distinguish 0 args, and 1 arg of type unit.

CHANGELOG.md

@@ -32,6 +32,7 @@ subset of the arguments, and return a curried type with the remaining ones https
 - Curried after uncurried is not fused anymore: `(. x) => y => 3` is not equivalent to `(. x, y) => 3` anymore. It's instead equivalent to `(. x) => { y => 3 }`.
 Also, `(. int) => string => bool` is not equivalen to `(. int, string) => bool` anymore.
 These are only breaking changes for unformatted code.
+- Distinguish between uncurried type `(. ()) => int`, whch takes 0 arguments, and `(. unit) => int` which takes 1 argument of type `unit` https://github.com/rescript-lang/rescript-compiler/pull/5821
 
 #### :bug: Bug Fix
 

jscomp/test/poly_variant_test.res

@@ -81,7 +81,7 @@ external on: (
   @string
   [
     | #line((. string) => unit)
-    | #close((. unit) => unit)
+    | #close((. ()) => unit)
   ],
 ) => unit = "on"
 

jscomp/test/reactTestUtils.res

@@ -3,7 +3,7 @@ type undefined = Js.undefined<unit>
 let undefined: undefined = Js.Undefined.empty
 
 @module("react-dom/test-utils")
-external reactAct: ((. unit) => undefined) => unit = "act"
+external reactAct: ((. ()) => undefined) => unit = "act"
 
 let act: (unit => unit) => unit = func => {
   let reactFunc = (. ()) => {
@@ -14,7 +14,7 @@ let act: (unit => unit) => unit = func => {
 }
 
 @module("react-dom/test-utils")
-external reactActAsync: ((. unit) => Js.Promise.t<'a>) => Js.Promise.t<unit> = "act"
+external reactActAsync: ((. ()) => Js.Promise.t<'a>) => Js.Promise.t<unit> = "act"
 
 let actAsync = func => {
   let reactFunc = (. ()) => func()

lib/4.06.1/unstable/js_compiler.ml

@@ -54752,9 +54752,10 @@ and printTypExpr ~state (typExpr : Parsetree.core_type) cmtTbl =
     | Ptyp_object (fields, openFlag) ->
       printObject ~state ~inline:false fields openFlag cmtTbl
     | Ptyp_arrow _ -> printArrow ~uncurried:false typExpr
+    | Ptyp_constr ({txt = Lident "()"}, []) -> Doc.text "()"
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), "arity0")}, [tArg]) ->
-      let unitConstr = Location.mkloc (Longident.Lident "unit") tArg.ptyp_loc in
-      let tUnit = Ast_helper.Typ.constr unitConstr [] in
+      let parensConstr = Location.mkloc (Longident.Lident "()") tArg.ptyp_loc in
+      let tUnit = Ast_helper.Typ.constr parensConstr [] in
       printArrow ~uncurried:true ~arity:1
         {tArg with ptyp_desc = Ptyp_arrow (Nolabel, tUnit, tArg)}
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), arity)}, [tArg])

lib/4.06.1/unstable/js_playground_compiler.ml

@@ -54752,9 +54752,10 @@ and printTypExpr ~state (typExpr : Parsetree.core_type) cmtTbl =
     | Ptyp_object (fields, openFlag) ->
       printObject ~state ~inline:false fields openFlag cmtTbl
     | Ptyp_arrow _ -> printArrow ~uncurried:false typExpr
+    | Ptyp_constr ({txt = Lident "()"}, []) -> Doc.text "()"
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), "arity0")}, [tArg]) ->
-      let unitConstr = Location.mkloc (Longident.Lident "unit") tArg.ptyp_loc in
-      let tUnit = Ast_helper.Typ.constr unitConstr [] in
+      let parensConstr = Location.mkloc (Longident.Lident "()") tArg.ptyp_loc in
+      let tUnit = Ast_helper.Typ.constr parensConstr [] in
       printArrow ~uncurried:true ~arity:1
         {tArg with ptyp_desc = Ptyp_arrow (Nolabel, tUnit, tArg)}
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), arity)}, [tArg])
@@ -166636,14 +166637,15 @@ and parseEs6ArrowType ~attrs p =
             if p.uncurried_by_default then not dotted else dotted
           in
           if uncurried && (paramNum = 1 || not p.uncurried_by_default) then
-            let isUnit =
+            let isParens =
               match typ.ptyp_desc with
-              | Ptyp_constr ({txt = Lident "unit"}, []) -> true
+              | Ptyp_constr ({txt = Lident "unit"; loc}, []) ->
+                loc.loc_end.pos_cnum - loc.loc_start.pos_cnum = 2 (* () *)
               | _ -> false
             in
             let loc = mkLoc startPos endPos in
             let fnArity, tArg =
-              if isUnit && arity = 1 then (0, t)
+              if isParens && arity = 1 then (0, t)
               else (arity, Ast_helper.Typ.arrow ~loc ~attrs argLbl typ t)
             in
             ( paramNum - 1,

lib/4.06.1/whole_compiler.ml

@@ -109750,9 +109750,10 @@ and printTypExpr ~state (typExpr : Parsetree.core_type) cmtTbl =
     | Ptyp_object (fields, openFlag) ->
       printObject ~state ~inline:false fields openFlag cmtTbl
     | Ptyp_arrow _ -> printArrow ~uncurried:false typExpr
+    | Ptyp_constr ({txt = Lident "()"}, []) -> Doc.text "()"
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), "arity0")}, [tArg]) ->
-      let unitConstr = Location.mkloc (Longident.Lident "unit") tArg.ptyp_loc in
-      let tUnit = Ast_helper.Typ.constr unitConstr [] in
+      let parensConstr = Location.mkloc (Longident.Lident "()") tArg.ptyp_loc in
+      let tUnit = Ast_helper.Typ.constr parensConstr [] in
       printArrow ~uncurried:true ~arity:1
         {tArg with ptyp_desc = Ptyp_arrow (Nolabel, tUnit, tArg)}
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), arity)}, [tArg])
@@ -180068,14 +180069,15 @@ and parseEs6ArrowType ~attrs p =
             if p.uncurried_by_default then not dotted else dotted
           in
           if uncurried && (paramNum = 1 || not p.uncurried_by_default) then
-            let isUnit =
+            let isParens =
               match typ.ptyp_desc with
-              | Ptyp_constr ({txt = Lident "unit"}, []) -> true
+              | Ptyp_constr ({txt = Lident "unit"; loc}, []) ->
+                loc.loc_end.pos_cnum - loc.loc_start.pos_cnum = 2 (* () *)
               | _ -> false
             in
             let loc = mkLoc startPos endPos in
             let fnArity, tArg =
-              if isUnit && arity = 1 then (0, t)
+              if isParens && arity = 1 then (0, t)
               else (arity, Ast_helper.Typ.arrow ~loc ~attrs argLbl typ t)
             in
             ( paramNum - 1,

res_syntax/src/res_core.ml

@@ -4250,14 +4250,15 @@ and parseEs6ArrowType ~attrs p =
             if p.uncurried_by_default then not dotted else dotted
           in
           if uncurried && (paramNum = 1 || not p.uncurried_by_default) then
-            let isUnit =
+            let isParens =
               match typ.ptyp_desc with
-              | Ptyp_constr ({txt = Lident "unit"}, []) -> true
+              | Ptyp_constr ({txt = Lident "unit"; loc}, []) ->
+                loc.loc_end.pos_cnum - loc.loc_start.pos_cnum = 2 (* () *)
               | _ -> false
             in
             let loc = mkLoc startPos endPos in
             let fnArity, tArg =
-              if isUnit && arity = 1 then (0, t)
+              if isParens && arity = 1 then (0, t)
               else (arity, Ast_helper.Typ.arrow ~loc ~attrs argLbl typ t)
             in
             ( paramNum - 1,

res_syntax/src/res_printer.ml

@@ -1653,9 +1653,10 @@ and printTypExpr ~state (typExpr : Parsetree.core_type) cmtTbl =
     | Ptyp_object (fields, openFlag) ->
       printObject ~state ~inline:false fields openFlag cmtTbl
     | Ptyp_arrow _ -> printArrow ~uncurried:false typExpr
+    | Ptyp_constr ({txt = Lident "()"}, []) -> Doc.text "()"
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), "arity0")}, [tArg]) ->
-      let unitConstr = Location.mkloc (Longident.Lident "unit") tArg.ptyp_loc in
-      let tUnit = Ast_helper.Typ.constr unitConstr [] in
+      let parensConstr = Location.mkloc (Longident.Lident "()") tArg.ptyp_loc in
+      let tUnit = Ast_helper.Typ.constr parensConstr [] in
       printArrow ~uncurried:true ~arity:1
         {tArg with ptyp_desc = Ptyp_arrow (Nolabel, tUnit, tArg)}
     | Ptyp_constr ({txt = Ldot (Ldot (Lident "Js", "Fn"), arity)}, [tArg])

res_syntax/tests/parsing/grammar/expressions/UncurriedByDefault.res

@@ -14,6 +14,22 @@ type mixTyp = (string, .string, string) => (string, string, string) => (string,
 type bTyp = (. string) => string => int
 type cTyp2 = (string, string) => int
 type uTyp2 = (.string, string) => int
+type cu = unit => int
+type cp = () => int
+type cuu = unit => unit => int
+type cpu = () => unit => int
+type cup = unit => () => int
+type cpp = () => () => int
+type cu2 = (unit, unit) => unit
+type cp2 = ((), ()) => unit
+type uu = (. unit) => int
+type up = (. ()) => int
+type uuu = (. unit) => (. unit) => int
+type upu = (. ()) => (. unit) => int
+type uup = (. unit) => (. ()) => int
+type upp = (. ()) => (. ()) => int
+type uu2 = (. unit, unit) => unit
+type up2 = (. (), ()) => unit
 
 @@uncurried
 
@@ -34,5 +50,21 @@ type mixTyp = (.string) => (string, string) => (.string, string, string, string)
 type bTyp = string => (. string) => int
 type cTyp2 = (.string, string) => int
 type uTyp2 = (string, string) => int
+type cu = (. unit) => int
+type cp = (. ()) => int
+type cuu = (. unit) => (. unit) => int
+type cpu = (. ()) => (. unit) => int
+type cup = (. unit) => (. ()) => int
+type cpp = (. ()) => (. ()) => int
+type cu2 = (. unit, unit) => unit
+type cp2 = (. (), ()) => unit
+type uu = unit => int
+type up = () => int
+type uuu = unit => unit => int
+type upu = () => unit => int
+type uup = unit => () => int
+type upp = () => () => int
+type uu2 = (unit, unit) => unit
+type up2 = ((), ()) => unit
 
 let pipe1 = 3->f

res_syntax/tests/parsing/grammar/expressions/expected/UncurriedByDefault.res.txt

@@ -24,6 +24,22 @@ type nonrec mixTyp =
 type nonrec bTyp = (string -> string -> int) Js.Fn.arity1
 type nonrec cTyp2 = string -> string -> int
 type nonrec uTyp2 = (string -> string -> int) Js.Fn.arity2
+type nonrec cu = unit -> int
+type nonrec cp = unit -> int
+type nonrec cuu = unit -> unit -> int
+type nonrec cpu = unit -> unit -> int
+type nonrec cup = unit -> unit -> int
+type nonrec cpp = unit -> unit -> int
+type nonrec cu2 = unit -> unit -> unit
+type nonrec cp2 = unit -> unit -> unit
+type nonrec uu = (unit -> int) Js.Fn.arity1
+type nonrec up = int Js.Fn.arity0
+type nonrec uuu = (unit -> (unit -> int) Js.Fn.arity1) Js.Fn.arity1
+type nonrec upu = (unit -> int) Js.Fn.arity1 Js.Fn.arity0
+type nonrec uup = (unit -> int Js.Fn.arity0) Js.Fn.arity1
+type nonrec upp = int Js.Fn.arity0 Js.Fn.arity0
+type nonrec uu2 = (unit -> unit -> unit) Js.Fn.arity2
+type nonrec up2 = (unit -> unit -> unit) Js.Fn.arity2
 [@@@uncurried ]
 let cApp = foo 3
 let uApp = ((foo 3)[@bs ])
@@ -52,4 +68,20 @@ type nonrec mixTyp =
 type nonrec bTyp = (string -> string -> int) Js.Fn.arity1
 type nonrec cTyp2 = string -> string -> int
 type nonrec uTyp2 = (string -> string -> int) Js.Fn.arity2
+type nonrec cu = unit -> int
+type nonrec cp = unit -> int
+type nonrec cuu = unit -> unit -> int
+type nonrec cpu = unit -> unit -> int
+type nonrec cup = unit -> unit -> int
+type nonrec cpp = unit -> unit -> int
+type nonrec cu2 = unit -> unit -> unit
+type nonrec cp2 = unit -> unit -> unit
+type nonrec uu = (unit -> int) Js.Fn.arity1
+type nonrec up = int Js.Fn.arity0
+type nonrec uuu = (unit -> (unit -> int) Js.Fn.arity1) Js.Fn.arity1
+type nonrec upu = (unit -> int) Js.Fn.arity1 Js.Fn.arity0
+type nonrec uup = (unit -> int Js.Fn.arity0) Js.Fn.arity1
+type nonrec upp = int Js.Fn.arity0 Js.Fn.arity0
+type nonrec uu2 = (unit -> unit -> unit) Js.Fn.arity2
+type nonrec up2 = (unit -> unit -> unit) Js.Fn.arity2
 let pipe1 = 3 |.u f

res_syntax/tests/parsing/grammar/typexpr/uncurried.res

@@ -9,6 +9,6 @@ type t = @attr (. float) => @attr2 int => @attr3 (. bool) => @attr4 string => un
 type t = (. (@attr float), (@attr2 int), . (@attr3 bool), (@attr4 string)) => unit
 
 @bs.val
-external setTimeout : ((. unit) => unit, int) => timerId = "setTimeout"
+external setTimeout : ((. ()) => unit, int) => timerId = "setTimeout"
 // totally different meaning
 external setTimeout : (. unit => unit, int) => timerId = "setTimeout"

res_syntax/tests/printer/expr/UncurriedByDefault.res

@@ -14,6 +14,22 @@ type mixTyp = (string, .string, string) => (string, string, string) => (string,
 type bTyp = (. string) => string => int
 type cTyp2 = (string, string) => int
 type uTyp2 = (.string, string) => int
+type cu = unit => int
+type cp = () => int
+type cuu = unit => unit => int
+type cpu = () => unit => int
+type cup = unit => () => int
+type cpp = () => () => int
+type cu2 = (unit, unit) => unit
+type cp2 = ((), ()) => unit
+type uu = (. unit) => int
+type up = (. ()) => int
+type uuu = (. unit) => (. unit) => int
+type upu = (. ()) => (. unit) => int
+type uup = (. unit) => (. ()) => int
+type upp = (. ()) => (. ()) => int
+type uu2 = (. unit, unit) => unit
+type up2 = (. (), ()) => unit
 
 let pipe = a->foo(. b, c)
 
@@ -36,5 +52,21 @@ type mixTyp = (.string) => (string, string) => (.string, string, string, string)
 type bTyp = string => (. string) => int
 type cTyp2 = (. string, string) => int
 type uTyp2 = (string, string) => int
+type cu = (. unit) => int
+type cp = (. ()) => int
+type cuu = (. unit) => (. unit) => int
+type cpu = (. ()) => (. unit) => int
+type cup = (. unit) => (. ()) => int
+type cpp = (. ()) => (. ()) => int
+type cu2 = (. unit, unit) => unit
+type cp2 = (. (), ()) => unit
+type uu = unit => int
+type up = () => int
+type uuu = unit => unit => int
+type upu = () => unit => int
+type uup = unit => () => int
+type upp = () => () => int
+type uu2 = (unit, unit) => unit
+type up2 = ((), ()) => unit
 
 let pipe = a->foo(b, c)

res_syntax/tests/printer/expr/expected/UncurriedByDefault.res.txt

@@ -14,6 +14,22 @@ type mixTyp = string => (. string, string) => (string, string, string, string) =
 type bTyp = (. string) => string => int
 type cTyp2 = (string, string) => int
 type uTyp2 = (. string, string) => int
+type cu = unit => int
+type cp = unit => int
+type cuu = (unit, unit) => int
+type cpu = (unit, unit) => int
+type cup = (unit, unit) => int
+type cpp = (unit, unit) => int
+type cu2 = (unit, unit) => unit
+type cp2 = (unit, unit) => unit
+type uu = (. unit) => int
+type up = (. ()) => int
+type uuu = (. unit) => (. unit) => int
+type upu = (. ()) => (. unit) => int
+type uup = (. unit) => (. ()) => int
+type upp = (. ()) => (. ()) => int
+type uu2 = (. unit, unit) => unit
+type up2 = (. unit, unit) => unit
 
 let pipe = a->foo(. b, c)
 
@@ -36,5 +52,21 @@ type mixTyp = (. string) => (string, string) => (. string, string, string, strin
 type bTyp = string => (. string) => int
 type cTyp2 = (. string, string) => int
 type uTyp2 = (string, string) => int
+type cu = (. unit) => int
+type cp = (. unit) => int
+type cuu = (. unit, unit) => int
+type cpu = (. unit, unit) => int
+type cup = (. unit, unit) => int
+type cpp = (. unit, unit) => int
+type cu2 = (. unit, unit) => unit
+type cp2 = (. unit, unit) => unit
+type uu = unit => int
+type up = () => int
+type uuu = unit => unit => int
+type upu = () => unit => int
+type uup = unit => () => int
+type upp = () => () => int
+type uu2 = (unit, unit) => unit
+type up2 = (unit, unit) => unit
 
 let pipe = a->foo(b, c)