Fix arity of inner functions.

The parser gives arity to inner functions while it should only give it to the toplevel for a nested function.
E.g. (x,y) => x+y should give toplevel arity 2, and no inner arity 1

compiler/syntax/src/res_core.ml

@@ -1596,8 +1596,8 @@ and parse_es6_arrow_expression ?(arrow_attrs = []) ?(arrow_start_pos = None)
             {attrs; label = lbl; expr = default_expr; pat; pos = start_pos} ->
           let loc = mk_loc start_pos end_pos in
           let fun_expr =
-            Ast_helper.Exp.fun_ ~loc ~attrs ~arity:(Some arity) lbl default_expr
-              pat expr
+            Ast_helper.Exp.fun_ ~loc ~attrs ~arity:None lbl default_expr pat
+              expr
           in
           if term_param_num = 1 then
             ( term_param_num - 1,

tests/syntax_tests/data/parsing/errors/expressions/expected/arrow.res.txt

@@ -11,5 +11,4 @@
 ;;(Object.keys providers).reduce
     (Function$
        (fun [arity:2]elements ->
-          fun [arity:1]providerId -> ((let x = 1 in let b = 2 in x + b)
-            [@res.braces ])))
+          fun providerId -> ((let x = 1 in let b = 2 in x + b)[@res.braces ])))

tests/syntax_tests/data/parsing/errors/expressions/expected/block.res.txt

@@ -66,11 +66,11 @@
 let findThreadByIdLinearScan =
   Function$
     (fun [arity:2]~threads:((threads)[@res.namedArgLoc ]) ->
-       fun [arity:1]~id:((id)[@res.namedArgLoc ]) ->
+       fun ~id:((id)[@res.namedArgLoc ]) ->
          ((Js.Array2.findi ThreadsModel.threads
              (Function$
                 (fun [arity:2]thread ->
-                   fun [arity:1]i ->
+                   fun i ->
                      ((let thisId =
                          match thread with
                          | ServerData.OneToOne

tests/syntax_tests/data/parsing/errors/expressions/expected/consecutive.res.txt

@@ -44,9 +44,8 @@
 
   consecutive expressions on a line must be separated by ';' or a newline
 
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> a + 3)
+let f = Function$ (fun [arity:2]a -> fun b -> a + 3)
 ;;b
-let f =
-  Function$ (fun [arity:2]g -> fun [arity:1]h -> ((a + 3; b)[@res.braces ]))
+let f = Function$ (fun [arity:2]g -> fun h -> ((a + 3; b)[@res.braces ]))
 let () = ((sideEffect1 (); sideEffect2 ())[@res.braces ])
 let () = ((let open Foo in let exception End  in x ())[@res.braces ])

tests/syntax_tests/data/parsing/errors/expressions/expected/emptyBlock.res.txt

@@ -1,2 +1,2 @@
 let x = {  }
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> {  })
+let f = Function$ (fun [arity:2]a -> fun b -> {  })

tests/syntax_tests/data/parsing/errors/other/expected/labelledParameters.res.txt

@@ -31,12 +31,10 @@
 
   A labeled parameter starts with a `~`. Did you mean: `~x`?
 
-let f =
-  Function$
-    (fun [arity:3]x -> fun [arity:2]?(y= 2) -> fun [arity:1]z -> (x + y) + z)
+let f = Function$ (fun [arity:3]x -> fun ?(y= 2) -> fun z -> (x + y) + z)
 let g =
   Function$
     (fun [arity:3]~x:((x)[@res.namedArgLoc ]) ->
-       fun [arity:2]?y:(((y)[@res.namedArgLoc ])= 2) ->
-         fun [arity:1]~z:((z)[@res.namedArgLoc ]) -> (x + y) + z)
+       fun ?y:(((y)[@res.namedArgLoc ])= 2) ->
+         fun ~z:((z)[@res.namedArgLoc ]) -> (x + y) + z)
 type nonrec f = (x:int -> y:int -> int, [ `Has_arity2 ]) function$

tests/syntax_tests/data/parsing/errors/structure/expected/gh16B.res.txt

@@ -35,7 +35,7 @@ module ClientSet =
                                  let cmp =
                                    Function$
                                      (fun [arity:2]a ->
-                                        fun [arity:1]b ->
+                                        fun b ->
                                           ((compare
                                               (a |.u Client.getUniqueId)
                                               (b |.u Client.getUniqueId))

tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedAlways.res.txt

@@ -1,7 +1,7 @@
 [@@@uncurried ]
-let foo = Function$ (fun [arity:2]x -> fun [arity:1]y -> x + y)
+let foo = Function$ (fun [arity:2]x -> fun y -> x + y)
 let z = foo 3 4
-let bar = Function$ (fun [arity:2]x -> fun [arity:1]y -> x + y)
+let bar = Function$ (fun [arity:2]x -> fun y -> x + y)
 let b = bar 3 4
 let w = 3 |.u (foo 4)
 let a = 3 |.u (foo 4)

tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedByDefault.res.txt

@@ -5,17 +5,15 @@ let uFun = Function$ (fun [arity:1]x -> 3)
 let mixFun =
   Function$
     (fun [arity:3]a ->
-       fun [arity:2]b ->
-         fun [arity:1]c ->
+       fun b ->
+         fun c ->
            Function$
              (fun [arity:3]d ->
-                fun [arity:2]e ->
-                  fun [arity:1]f ->
-                    Function$ (fun [arity:2]g -> fun [arity:1]h -> 4)))
+                fun e -> fun f -> Function$ (fun [arity:2]g -> fun h -> 4)))
 let bracesFun =
   Function$ (fun [arity:1]x -> Function$ (fun [arity:1]y -> x + y))
-let cFun2 = Function$ (fun [arity:2]x -> fun [arity:1]y -> 3)
-let uFun2 = Function$ (fun [arity:2]x -> fun [arity:1]y -> 3)
+let cFun2 = Function$ (fun [arity:2]x -> fun y -> 3)
+let uFun2 = Function$ (fun [arity:2]x -> fun y -> 3)
 type nonrec cTyp = (string -> int, [ `Has_arity1 ]) function$
 type nonrec uTyp = (string -> int, [ `Has_arity1 ]) function$
 type nonrec mixTyp =
@@ -77,19 +75,19 @@ let _ = Function$ ((fun [arity:1]x -> 34)[@res.async ][@att ])
 let _ = preserveAttr (Function$ ((fun [arity:1]x -> 34)[@att ]))
 let _ = preserveAttr (Function$ ((fun [arity:1]x -> 34)[@res.async ][@att ]))
 let t0 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t1 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t2 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t3 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t4 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t5 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t6 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 type nonrec arrowPath1 = (int -> string, [ `Has_arity1 ]) function$
 type nonrec arrowPath2 = (I.t -> string, [ `Has_arity1 ]) function$
 type nonrec arrowPath3 = (int -> string, [ `Has_arity1 ]) function$
@@ -109,18 +107,18 @@ let mixFun =
     (fun [arity:1]a ->
        Function$
          (fun [arity:2]b ->
-            fun [arity:1]c ->
+            fun c ->
               Function$
                 (fun [arity:3]d ->
-                   fun [arity:2]e ->
-                     fun [arity:1]f ->
+                   fun e ->
+                     fun f ->
                        Function$
                          (fun [arity:1]g -> Function$ (fun [arity:1]h -> 4)))))
 let bracesFun =
   Function$ (fun [arity:1]x -> Function$ (fun [arity:1]y -> x + y))
-let cFun2 = Function$ (fun [arity:2]x -> fun [arity:1]y -> 3)
-let uFun2 = Function$ (fun [arity:2]x -> fun [arity:1]y -> 3)
-let cFun2Dots = Function$ (fun [arity:2]x -> fun [arity:1]y -> 3)
+let cFun2 = Function$ (fun [arity:2]x -> fun y -> 3)
+let uFun2 = Function$ (fun [arity:2]x -> fun y -> 3)
+let cFun2Dots = Function$ (fun [arity:2]x -> fun y -> 3)
 type nonrec cTyp = (string -> int, [ `Has_arity1 ]) function$
 type nonrec uTyp = (string -> int, [ `Has_arity1 ]) function$
 type nonrec mixTyp =
@@ -184,13 +182,13 @@ let _ = Function$ ((fun [arity:1]x -> 34)[@res.async ][@att ])
 let _ = preserveAttr (Function$ ((fun [arity:1]x -> 34)[@att ]))
 let _ = preserveAttr (Function$ ((fun [arity:1]x -> 34)[@res.async ][@att ]))
 let t0 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t1 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t2 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 let t3 (type a) (type b) =
-  Function$ (fun [arity:2](l : a list) -> fun [arity:1](x : a) -> x :: l)
+  Function$ (fun [arity:2](l : a list) -> fun (x : a) -> x :: l)
 type nonrec arrowPath1 = (int -> string, [ `Has_arity1 ]) function$
 type nonrec arrowPath2 = (I.t -> string, [ `Has_arity1 ]) function$
 type nonrec arrowPath3 = (int -> string, [ `Has_arity1 ]) function$

tests/syntax_tests/data/parsing/grammar/expressions/expected/apply.res.txt

@@ -4,8 +4,7 @@
 ;;foo (Function$ (fun [arity:1]_ -> bla))
     (Function$ (fun [arity:1]_ -> blaz))
 ;;List.map (Function$ (fun [arity:1]x -> x + 1)) myList
-;;List.reduce
-    (Function$ (fun [arity:2]acc -> fun [arity:1]curr -> acc + curr)) 0
+;;List.reduce (Function$ (fun [arity:2]acc -> fun curr -> acc + curr)) 0
     myList
 let unitUncurried = apply ()
 ;;call ~a:(((((a)[@res.namedArgLoc ]) : int))[@res.namedArgLoc ])

tests/syntax_tests/data/parsing/grammar/expressions/expected/arrow.res.txt

@@ -3,99 +3,85 @@ let f = Function$ (fun [arity:1]_ -> Js.log {js|test|js})
 let f = Function$ (fun [arity:1]() -> Js.log {js|unit|js})
 let f = Function$ (fun [arity:1](Reducer (inst, comp)) -> inst.render comp)
 let f = Function$ (fun [arity:1](Instance) -> ())
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> a + b)
-let f = Function$ (fun [arity:2]1 -> fun [arity:1]2 -> ())
+let f = Function$ (fun [arity:2]a -> fun b -> a + b)
+let f = Function$ (fun [arity:2]1 -> fun 2 -> ())
 let f = Function$ (fun [arity:1]{js|stringPattern|js} -> ())
 let f =
   Function$
-    (fun [arity:2]{js|stringPattern|js} ->
-       fun [arity:1]{js|stringPattern|js} -> ())
+    (fun [arity:2]{js|stringPattern|js} -> fun {js|stringPattern|js} -> ())
 let f = Function$ (fun [arity:1]() -> ())
-let f = Function$ (fun [arity:2](a : int) -> fun [arity:1](b : int) -> a + b)
-let f = Function$ (fun [arity:2]_ -> fun [arity:1]_ -> ())
-let f =
-  Function$
-    (fun [arity:2][|a;b|] -> fun [arity:1][|c;d|] -> ((a + b) + c) + d)
+let f = Function$ (fun [arity:2](a : int) -> fun (b : int) -> a + b)
+let f = Function$ (fun [arity:2]_ -> fun _ -> ())
+let f = Function$ (fun [arity:2][|a;b|] -> fun [|c;d|] -> ((a + b) + c) + d)
 let f = Function$ (fun [arity:1]{ a } -> a + 1)
 let f =
-  Function$
-    (fun [arity:2]{ a; b } -> fun [arity:1]{ c; d } -> ((a + b) + c) + d)
+  Function$ (fun [arity:2]{ a; b } -> fun { c; d } -> ((a + b) + c) + d)
 let f = Function$ (fun [arity:1](a, b) -> a + b)
-let f =
-  Function$ (fun [arity:2](a, b) -> fun [arity:1](c, d) -> ((a + b) + c) + d)
+let f = Function$ (fun [arity:2](a, b) -> fun (c, d) -> ((a + b) + c) + d)
 let f = Function$ (fun [arity:1]exception Terminate -> ())
 let f =
-  Function$
-    (fun [arity:2]exception Terminate -> fun [arity:1]exception Exit -> ())
+  Function$ (fun [arity:2]exception Terminate -> fun exception Exit -> ())
 let f = Function$ (fun [arity:1][] -> ())
 let f = Function$ (fun [arity:1](x::xs) -> x + (xs |.u Belt.List.length))
-let f = Function$ (fun [arity:2](x : int) -> fun [arity:1](y : int) -> x + y)
+let f = Function$ (fun [arity:2](x : int) -> fun (y : int) -> x + y)
 let f =
   Function$
     (fun [arity:2]~a:((a)[@res.namedArgLoc ]) ->
-       fun [arity:1]~b:((b)[@res.namedArgLoc ]) -> a + b)
+       fun ~b:((b)[@res.namedArgLoc ]) -> a + b)
 let f =
   Function$
     (fun [arity:2]~a:((x)[@res.namedArgLoc ]) ->
-       fun [arity:1]~b:((y)[@res.namedArgLoc ]) -> x + y)
+       fun ~b:((y)[@res.namedArgLoc ]) -> x + y)
 let f =
   Function$
     (fun [arity:2]~a:(((x : int))[@res.namedArgLoc ]) ->
-       fun [arity:1]~b:(((y : int))[@res.namedArgLoc ]) -> x + y)
+       fun ~b:(((y : int))[@res.namedArgLoc ]) -> x + y)
 let f =
   Function$
     (fun [arity:3]?a:(((a)[@res.namedArgLoc ])= 1) ->
-       fun [arity:2]?b:(((b)[@res.namedArgLoc ])= 2) ->
-         fun [arity:1]c -> (a + b) + c)
+       fun ?b:(((b)[@res.namedArgLoc ])= 2) -> fun c -> (a + b) + c)
 let f =
   Function$
     (fun [arity:3]?a:(((x)[@res.namedArgLoc ])= 1) ->
-       fun [arity:2]?b:(((y)[@res.namedArgLoc ])= 2) ->
-         fun [arity:1]c -> (x + y) + c)
+       fun ?b:(((y)[@res.namedArgLoc ])= 2) -> fun c -> (x + y) + c)
 let f =
   Function$
     (fun [arity:3]?a:((((x : int))[@res.namedArgLoc ])= 1) ->
-       fun [arity:2]?b:((((y : int))[@res.namedArgLoc ])= 2) ->
-         fun [arity:1]c -> (x + y) + c)
+       fun ?b:((((y : int))[@res.namedArgLoc ])= 2) -> fun c -> (x + y) + c)
 let f =
   Function$
     (fun [arity:3]?a:((a)[@res.namedArgLoc ]) ->
-       fun [arity:2]?b:((b)[@res.namedArgLoc ]) ->
-         fun [arity:1]c ->
+       fun ?b:((b)[@res.namedArgLoc ]) ->
+         fun c ->
            match (a, b) with | (Some a, Some b) -> (a + b) + c | _ -> 3)
 let f =
   Function$
     (fun [arity:3]?a:((x)[@res.namedArgLoc ]) ->
-       fun [arity:2]?b:((y)[@res.namedArgLoc ]) ->
-         fun [arity:1]c ->
+       fun ?b:((y)[@res.namedArgLoc ]) ->
+         fun c ->
            match (x, y) with | (Some a, Some b) -> (a + b) + c | _ -> 3)
 let f =
   Function$
     (fun [arity:3]?a:(((x : int option))[@res.namedArgLoc ]) ->
-       fun [arity:2]?b:(((y : int option))[@res.namedArgLoc ]) ->
-         fun [arity:1]c ->
+       fun ?b:(((y : int option))[@res.namedArgLoc ]) ->
+         fun c ->
            match (x, y) with | (Some a, Some b) -> (a + b) + c | _ -> 3)
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> a + b)
+let f = Function$ (fun [arity:2]a -> fun b -> a + b)
 let f = Function$ (fun [arity:1]() -> ())
 let f = Function$ (fun [arity:1]() -> ())
-let f = Function$ (fun [arity:3]a -> fun [arity:2]b -> fun [arity:1]c -> ())
-let f =
-  Function$
-    (fun [arity:4]a ->
-       fun [arity:3]b -> fun [arity:2]c -> fun [arity:1]d -> ())
-let f = Function$ (fun [arity:3]a -> fun [arity:2]b -> fun [arity:1]c -> ())
+let f = Function$ (fun [arity:3]a -> fun b -> fun c -> ())
+let f = Function$ (fun [arity:4]a -> fun b -> fun c -> fun d -> ())
+let f = Function$ (fun [arity:3]a -> fun b -> fun c -> ())
 let f =
   Function$
     (fun [arity:4]~a:((a)[@res.namedArgLoc ][@attr ]) ->
-       fun [arity:3]b ->
-         fun [arity:2]~c:((c)[@res.namedArgLoc ][@attr ]) ->
-           fun [arity:1]d -> ())
+       fun b -> fun ~c:((c)[@res.namedArgLoc ][@attr ]) -> fun d -> ())
 let f =
   Function$
     (fun [arity:4]~a:((a)[@res.namedArgLoc ][@attr ]) ->
-       fun [arity:3]((b)[@attrOnB ]) ->
-         fun [arity:2]~c:((c)[@res.namedArgLoc ][@attr ]) ->
-           fun [arity:1]((d)[@attrOnD ]) -> ())
+       fun ((b)[@attrOnB ]) ->
+         fun ~c:((c)[@res.namedArgLoc ][@attr ]) ->
+           fun ((d)[@attrOnD ]) -> ())
 let f = Function$ (fun [arity:1]list -> list ())
 ;;match colour with
   | Red when

tests/syntax_tests/data/parsing/grammar/expressions/expected/async.res.txt

@@ -24,12 +24,9 @@ let async =
   [@res.braces ])
 let f =
   ((if isPositive
-    then
-      Function$ ((fun [arity:2]a -> fun [arity:1]b -> (a + b : int))
-        [@res.async ])
+    then Function$ ((fun [arity:2]a -> fun b -> (a + b : int))[@res.async ])
     else
-      Function$ (((fun [arity:2]c -> fun [arity:1]d -> (c - d : int)))
-        [@res.async ]))
+      Function$ (((fun [arity:2]c -> fun d -> (c - d : int)))[@res.async ]))
   [@res.ternary ])
 let foo = async ~a:((34)[@res.namedArgLoc ])
 let bar =

tests/syntax_tests/data/parsing/grammar/expressions/expected/block.res.txt

@@ -84,5 +84,5 @@ let reifyStyle (type a) =
 let calc_fps =
   Function$
     (fun [arity:2]t0 ->
-       fun [arity:1]t1 -> ((let delta = (t1 -. t0) /. 1000. in 1. /. delta)
+       fun t1 -> ((let delta = (t1 -. t0) /. 1000. in 1. /. delta)
          [@res.braces ]))

tests/syntax_tests/data/parsing/grammar/expressions/expected/firstClassModule.res.txt

@@ -16,13 +16,13 @@ let numbers = [three; (module struct let x = 4 end)]
 let plus =
   Function$
     (fun [arity:2]m1 ->
-       fun [arity:1]m2 -> ((((module
+       fun m2 -> ((((module
          struct let x = (to_int m1) + (to_int m2) end) : (module X_int)))
          [@res.braces ]))
 let plus =
   Function$
     (fun [arity:2]m1 ->
-       fun [arity:1]m2 -> ((module
+       fun m2 -> ((module
          struct let x = (to_int m1) + (to_int m2) end) : (module X_int)))
 let unique_instance = ((module
   struct module Query_handler = Unique
@@ -31,15 +31,15 @@ let build_instance (type a) =
   Function$
     (fun [arity:2]((module Q)  : (module Query_handler with type config = a))
        ->
-       fun [arity:1]config -> ((module
+       fun config -> ((module
          struct module Query_handler = Q
                 let this = Q.create config end) : (module
                                                     Query_handler_instance)))
 let build_instance (type a) =
   Function$
     (fun [arity:2]((module Q)  : (module Query_handler with type config = a))
        ->
-       fun [arity:1]config -> ((((module
+       fun config -> ((((module
          struct module Query_handler = Q
                 let this = Q.create config end) : (module
                                                     Query_handler_instance)))