From 2423ad020a44a6c2f55fe776e632d6bbb6992f3c Mon Sep 17 00:00:00 2001
From: Cristiano Calcagno <cristianoc@users.noreply.github.com>
Date: Thu, 12 Dec 2024 10:57:29 +0100
Subject: [PATCH] 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               |  4 +-
 .../errors/expressions/expected/arrow.res.txt |  3 +-
 .../errors/expressions/expected/block.res.txt |  4 +-
 .../expressions/expected/consecutive.res.txt  |  5 +-
 .../expressions/expected/emptyBlock.res.txt   |  2 +-
 .../other/expected/labelledParameters.res.txt |  8 +-
 .../errors/structure/expected/gh16B.res.txt   |  2 +-
 .../expected/UncurriedAlways.res.txt          |  4 +-
 .../expected/UncurriedByDefault.res.txt       | 46 ++++++------
 .../expressions/expected/apply.res.txt        |  3 +-
 .../expressions/expected/arrow.res.txt        | 74 ++++++++-----------
 .../expressions/expected/async.res.txt        |  7 +-
 .../expressions/expected/block.res.txt        |  2 +-
 .../expected/firstClassModule.res.txt         |  8 +-
 .../grammar/expressions/expected/jsx.res.txt  | 47 ++++++------
 .../expected/locallyAbstractTypes.res.txt     | 14 ++--
 .../expressions/expected/uncurried.res.txt    | 15 ++--
 .../expected/underscoreApply.res.txt          |  2 +-
 .../expected/firstClassModules.res.txt        |  2 +-
 .../grammar/modexpr/expected/functor.res.txt  |  2 +-
 .../grammar/pattern/expected/any.res.txt      |  4 +-
 .../grammar/pattern/expected/constant.res.txt |  2 +-
 .../pattern/expected/extension.res.txt        |  3 +-
 .../expected/firstClassModules.res.txt        | 13 ++--
 .../pattern/expected/polyvariants.res.txt     |  2 +-
 .../grammar/pattern/expected/unit.res.txt     |  4 +-
 .../expected/equalAfterBinaryExpr.res.txt     |  4 +-
 .../expected/nonRecTypes.res.txt              | 54 +++++++-------
 .../expression/expected/emptyBlock.res.txt    |  2 +-
 29 files changed, 149 insertions(+), 193 deletions(-)

diff --git a/compiler/syntax/src/res_core.ml b/compiler/syntax/src/res_core.ml
index 610a37b734..e99a4ec156 100644
--- a/compiler/syntax/src/res_core.ml
+++ b/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,
diff --git a/tests/syntax_tests/data/parsing/errors/expressions/expected/arrow.res.txt b/tests/syntax_tests/data/parsing/errors/expressions/expected/arrow.res.txt
index 921b269614..c21d3abef2 100644
--- a/tests/syntax_tests/data/parsing/errors/expressions/expected/arrow.res.txt
+++ b/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 ])))
\ No newline at end of file
+          fun providerId -> ((let x = 1 in let b = 2 in x + b)[@res.braces ])))
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/errors/expressions/expected/block.res.txt b/tests/syntax_tests/data/parsing/errors/expressions/expected/block.res.txt
index 636937df30..13d6efcccf 100644
--- a/tests/syntax_tests/data/parsing/errors/expressions/expected/block.res.txt
+++ b/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
diff --git a/tests/syntax_tests/data/parsing/errors/expressions/expected/consecutive.res.txt b/tests/syntax_tests/data/parsing/errors/expressions/expected/consecutive.res.txt
index 9d12fcc36f..431ca31f84 100644
--- a/tests/syntax_tests/data/parsing/errors/expressions/expected/consecutive.res.txt
+++ b/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 ])
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/errors/expressions/expected/emptyBlock.res.txt b/tests/syntax_tests/data/parsing/errors/expressions/expected/emptyBlock.res.txt
index b08fdd7412..fca8935cc9 100644
--- a/tests/syntax_tests/data/parsing/errors/expressions/expected/emptyBlock.res.txt
+++ b/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 -> {  })
\ No newline at end of file
+let f = Function$ (fun [arity:2]a -> fun b -> {  })
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/errors/other/expected/labelledParameters.res.txt b/tests/syntax_tests/data/parsing/errors/other/expected/labelledParameters.res.txt
index ad41ffd983..d42c21ede3 100644
--- a/tests/syntax_tests/data/parsing/errors/other/expected/labelledParameters.res.txt
+++ 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$
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/errors/structure/expected/gh16B.res.txt b/tests/syntax_tests/data/parsing/errors/structure/expected/gh16B.res.txt
index 278e3ab31b..39d03805ec 100644
--- a/tests/syntax_tests/data/parsing/errors/structure/expected/gh16B.res.txt
+++ b/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))
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedAlways.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedAlways.res.txt
index 8e6a52419c..cd268cd8a5 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedAlways.res.txt
+++ b/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)
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedByDefault.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedByDefault.res.txt
index 4d86f16622..1d60dbec09 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/UncurriedByDefault.res.txt
+++ b/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$
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/apply.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/apply.res.txt
index a08df40ebd..1a0f7fdc0e 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/apply.res.txt
+++ b/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 ])
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/arrow.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/arrow.res.txt
index 9060aa6494..36cc7d1c18 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/arrow.res.txt
+++ b/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
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/async.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/async.res.txt
index d76ad3ec36..245e144a22 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/async.res.txt
+++ b/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 =
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/block.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/block.res.txt
index 556b20feda..2e9038568e 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/block.res.txt
+++ b/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 ]))
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/firstClassModule.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/firstClassModule.res.txt
index f9f3af0c9c..7769f2dbe1 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/firstClassModule.res.txt
+++ b/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
@@ -31,7 +31,7 @@ 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)))
@@ -39,7 +39,7 @@ 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)))
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/jsx.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/jsx.res.txt
index cd3f51ae10..ebbbcb723f 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/jsx.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/expressions/expected/jsx.res.txt
@@ -151,12 +151,12 @@ let y =
       [@res.namedArgLoc ]) ~isHistorical:((true)[@res.namedArgLoc ])
       ~onHashChange:((Function$
                         (fun [arity:3]_oldPath ->
-                           fun [arity:2]_oldUrl ->
-                             fun [arity:1]newUrl ->
+                           fun _oldUrl ->
+                             fun newUrl ->
                                updater
                                  (Function$
                                     (fun [arity:2]latestComponentBag ->
-                                       fun [arity:1]_ ->
+                                       fun _ ->
                                          ((let currentActualPath =
                                              Routes.hashOfUri newUrl in
                                            let pathFromState =
@@ -345,10 +345,10 @@ let _ =
   ((StaticDiv.createElement
       ~onClick:((Function$
                    (fun [arity:5]foo ->
-                      fun [arity:4]bar ->
-                        fun [arity:3]baz ->
-                          fun [arity:2]lineBreak ->
-                            fun [arity:1]identifier ->
+                      fun bar ->
+                        fun baz ->
+                          fun lineBreak ->
+                            fun identifier ->
                               ((doStuff foo bar baz; bar lineBreak identifier)
                               [@res.braces ])))
       [@res.namedArgLoc ][@res.braces ]) ~children:[] ())
@@ -369,16 +369,11 @@ let _ =
   ((StaticDivNamed.createElement
       ~onClick:((Function$
                    (fun [arity:6]~foo:((foo)[@res.namedArgLoc ]) ->
-                      fun [arity:5]~bar:((bar)[@res.namedArgLoc ]) ->
-                        fun [arity:4]~baz:((baz)[@res.namedArgLoc ]) ->
-                          fun
-                            [arity:3]~lineBreak:((lineBreak)[@res.namedArgLoc
-                                                              ])
-                            ->
-                            fun
-                              [arity:2]~identifier:((identifier)[@res.namedArgLoc
-                                                                  ])
-                              -> fun [arity:1]() -> bar lineBreak identifier))
+                      fun ~bar:((bar)[@res.namedArgLoc ]) ->
+                        fun ~baz:((baz)[@res.namedArgLoc ]) ->
+                          fun ~lineBreak:((lineBreak)[@res.namedArgLoc ]) ->
+                            fun ~identifier:((identifier)[@res.namedArgLoc ])
+                              -> fun () -> bar lineBreak identifier))
       [@res.namedArgLoc ][@res.braces ]) ~children:[] ())
   [@JSX ])
 let _ =
@@ -392,7 +387,7 @@ let _ =
   ((div
       ~onClick:((Function$
                    (fun [arity:2]e ->
-                      fun [arity:1]e2 -> (((doStuff (); bar foo)
+                      fun e2 -> (((doStuff (); bar foo)
                         [@res.braces ]) : event)))
       [@res.namedArgLoc ][@res.braces ]) ~children:[] ())
   [@JSX ])
@@ -400,10 +395,10 @@ let _ =
   ((div
       ~onClick:((Function$
                    (fun [arity:5]foo ->
-                      fun [arity:4]bar ->
-                        fun [arity:3]baz ->
-                          fun [arity:2]superLongIdent ->
-                            fun [arity:1]breakLine -> (((doStuff (); bar foo)
+                      fun bar ->
+                        fun baz ->
+                          fun superLongIdent ->
+                            fun breakLine -> (((doStuff (); bar foo)
                               [@res.braces ]) : (event * event2 * event3 *
                                                   event4 * event5))))
       [@res.namedArgLoc ][@res.braces ]) ~children:[] ())
@@ -412,10 +407,10 @@ let _ =
   ((div
       ~onClick:((Function$
                    (fun [arity:5]foo ->
-                      fun [arity:4]bar ->
-                        fun [arity:3]baz ->
-                          fun [arity:2]superLongIdent ->
-                            fun [arity:1]breakLine ->
+                      fun bar ->
+                        fun baz ->
+                          fun superLongIdent ->
+                            fun breakLine ->
                               (doStuff () : (event * event2 * event3 * event4
                                               * event5))))
       [@res.namedArgLoc ][@res.braces ]) ~children:[] ())
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/locallyAbstractTypes.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/locallyAbstractTypes.res.txt
index 2e3d1e4b3b..7e6f17ed76 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/locallyAbstractTypes.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/expressions/expected/locallyAbstractTypes.res.txt
@@ -1,25 +1,22 @@
 let f (type t) = Function$ (fun [arity:1](xs : t list) -> ())
 let f (type t) =
   Function$
-    (fun [arity:2](xs : t list) -> fun (type s) ->
-       fun [arity:1](ys : s list) -> ())
+    (fun [arity:2](xs : t list) -> fun (type s) -> fun (ys : s list) -> ())
 let f (type t) (type u) (type v) =
   Function$ (fun [arity:1](xs : (t * u * v) list) -> ())
 let f (type t) (type u) (type v) =
   Function$
     (fun [arity:2](xs : (t * u * v) list) -> fun (type s) -> fun (type w) ->
-       fun (type z) -> fun [arity:1](ys : (s * w * z) list) -> ())
+       fun (type z) -> fun (ys : (s * w * z) list) -> ())
 let f = ((fun (type t) -> fun (type u) -> fun (type v) ->
   Function$
     (fun [arity:2](xs : (t * u * v) list) -> ((fun (type s) -> fun (type w)
-       -> fun (type z) -> fun [arity:1](ys : (s * w * z) list) -> ())
-       [@attr2 ])))
+       -> fun (type z) -> fun (ys : (s * w * z) list) -> ())[@attr2 ])))
   [@attr ])
 let f = ((fun (type t) -> ((fun (type s) ->
   Function$
     (fun [arity:2](xs : (t * s) list) -> ((fun (type u) -> ((fun (type v) ->
-       fun (type w) -> fun [arity:1](ys : (u * v * w) list) -> ())[@attr ]))
-       [@attr ])))
+       fun (type w) -> fun (ys : (u * v * w) list) -> ())[@attr ]))[@attr ])))
   [@attr ]))[@attr ])
 let cancel_and_collect_callbacks :
   'a 'u 'c .
@@ -27,5 +24,4 @@ let cancel_and_collect_callbacks :
       [ `Has_arity2 ]) function$
   = fun (type x) ->
   Function$
-    (fun [arity:2]callbacks_accumulator ->
-       fun [arity:1](p : (_, _, c) promise) -> ())
\ No newline at end of file
+    (fun [arity:2]callbacks_accumulator -> fun (p : (_, _, c) promise) -> ())
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/uncurried.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/uncurried.res.txt
index 1b6cb630d1..46c2414859 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/uncurried.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/expressions/expected/uncurried.res.txt
@@ -1,10 +1,7 @@
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> a + b)
-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:2]a -> fun b -> a + b)
 let f =
-  Function$
-    (fun [arity:4]a ->
-       fun [arity:3]b ->
-         fun [arity:2]c -> fun [arity:1]d -> ((a + b) + c) + d)
+  Function$ (fun [arity:4]a -> fun b -> fun c -> fun d -> ((a + b) + c) + d)
 let f =
   Function$
     ((fun [arity:1]a ->
@@ -19,12 +16,10 @@ let f =
 let f =
   Function$
     (fun [arity:4]((a)[@attr ]) ->
-       fun [arity:3]((b)[@attr2 ]) ->
-         fun [arity:2]((c)[@attr3 ]) -> fun [arity:1]((d)[@attr4 ]) -> ())
+       fun ((b)[@attr2 ]) -> fun ((c)[@attr3 ]) -> fun ((d)[@attr4 ]) -> ())
 let f =
   Function$
     (fun [arity:4]((a)[@attr ]) ->
-       fun [arity:3]((b)[@attr2 ]) ->
-         fun [arity:2]((c)[@attr3 ]) -> fun [arity:1]((d)[@attr4 ]) -> ())
+       fun ((b)[@attr2 ]) -> fun ((c)[@attr3 ]) -> fun ((d)[@attr4 ]) -> ())
 ;;add 1 2
 ;;add 2 3 4 5 6 7 8 9 10
\ No newline at end of file
diff --git a/tests/syntax_tests/data/parsing/grammar/expressions/expected/underscoreApply.res.txt b/tests/syntax_tests/data/parsing/grammar/expressions/expected/underscoreApply.res.txt
index 86a8b0da28..ebfa3f12d5 100644
--- a/tests/syntax_tests/data/parsing/grammar/expressions/expected/underscoreApply.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/expressions/expected/underscoreApply.res.txt
@@ -24,7 +24,7 @@ let l2 =
 let optParam =
   Function$
     (fun [arity:2]?v:((v)[@res.namedArgLoc ]) ->
-       fun [arity:1]() -> ((if v = None then 0 else 1)[@res.ternary ]))
+       fun () -> ((if v = None then 0 else 1)[@res.ternary ]))
 let l1 =
   List.length
     (List.map (Function$ (fun [arity:1]__x -> optParam ?v:__x ()))
diff --git a/tests/syntax_tests/data/parsing/grammar/modexpr/expected/firstClassModules.res.txt b/tests/syntax_tests/data/parsing/grammar/modexpr/expected/firstClassModules.res.txt
index 1c09739d12..55f32eeffe 100644
--- a/tests/syntax_tests/data/parsing/grammar/modexpr/expected/firstClassModules.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/modexpr/expected/firstClassModules.res.txt
@@ -5,7 +5,7 @@ module Device = (val
 let draw_using_device =
   Function$
     (fun [arity:2]device_name ->
-       fun [arity:1]picture ->
+       fun picture ->
          ((let module Device = (val
              (Hashtbl.find devices device_name : (module DEVICE))) in
              Device.draw picture)
diff --git a/tests/syntax_tests/data/parsing/grammar/modexpr/expected/functor.res.txt b/tests/syntax_tests/data/parsing/grammar/modexpr/expected/functor.res.txt
index 7f898aba98..415ac22303 100644
--- a/tests/syntax_tests/data/parsing/grammar/modexpr/expected/functor.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/modexpr/expected/functor.res.txt
@@ -32,7 +32,7 @@ module Make(Cmp:sig
     let add =
       Function$
         (fun [arity:2](y : coll) ->
-           fun [arity:1](e : key) ->
+           fun (e : key) ->
              if List.exists (Function$ (fun [arity:1]x -> eq x e)) y
              then y
              else e :: y)
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/any.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/any.res.txt
index 3123064d47..80c80c49d3 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/any.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/any.res.txt
@@ -22,8 +22,8 @@ let f = Function$ (fun [arity:1](_ as _x) -> ())
 let f = Function$ (fun [arity:1](_ : unit) -> ())
 let f = Function$ (fun [arity:1](_ : unit) -> ())
 let f = Function$ (fun [arity:1]((_ : unit) as _x) -> ())
-let g = Function$ (fun [arity:2]a -> fun [arity:1]_ -> ())
-let g = Function$ (fun [arity:2]_ -> fun [arity:1]a -> ())
+let g = Function$ (fun [arity:2]a -> fun _ -> ())
+let g = Function$ (fun [arity:2]_ -> fun a -> ())
 ;;for _ = 0 to 10 do () done
 ;;for _ as _x = 0 to 10 do () done
 ;;for _ = 0 to 10 do () done
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/constant.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/constant.res.txt
index 713dc033fc..70ade709ab 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/constant.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/constant.res.txt
@@ -52,7 +52,7 @@ let _0 = 0x9A
 let print =
   Function$
     (fun [arity:2]ppf ->
-       fun [arity:1]i ->
+       fun i ->
          match i.stamp with
          | 0 -> fprintf ppf {js|%s!|js} i.name
          | (-1) -> fprintf ppf {js|%s#|js} i.name
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/extension.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/extension.res.txt
index 9c5b5db261..e669ad16e2 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/extension.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/extension.res.txt
@@ -15,8 +15,7 @@ let f = Function$ (fun [arity:1][%patternExtension ] -> ())
 let f = Function$ (fun [arity:1][%pattern.extension ] -> ())
 let f = Function$ (fun [arity:1][%raw {js|x|js}] -> ())
 let f =
-  Function$
-    (fun [arity:2][%raw {js|x|js}] -> fun [arity:1][%raw {js|y|js}] -> ())
+  Function$ (fun [arity:2][%raw {js|x|js}] -> fun [%raw {js|y|js}] -> ())
 let f = Function$ (fun [arity:1]([%raw {js|x|js}] as _y) -> ())
 let f = Function$ (fun [arity:1]([%raw {js|x|js}] : unit) -> ())
 let f = Function$ (fun [arity:1]([%patExt1 ]|[%patExt2 ]) -> ())
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/firstClassModules.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/firstClassModules.res.txt
index 875aa2d5a5..c971522621 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/firstClassModules.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/firstClassModules.res.txt
@@ -1,22 +1,19 @@
-let sort (type s) =
-  Function$ (fun [arity:2](module Set)  -> fun [arity:1]l -> ())
+let sort (type s) = Function$ (fun [arity:2](module Set)  -> fun l -> ())
 let sort (type s) =
   Function$
     (fun [arity:2]((module Set)  : (module Set.S with type elt = s)) ->
-       fun [arity:1]l -> ())
+       fun l -> ())
 let sort (type s) =
   Function$
     (fun
        [arity:2]((module Set)  :
                   (module Set.S with type elt = s and type elt2 = t))
-       -> fun [arity:1]l -> ())
-let foo =
-  Function$ (fun [arity:2](module Foo)  -> fun [arity:1]baz -> Foo.bar baz)
+       -> fun l -> ())
+let foo = Function$ (fun [arity:2](module Foo)  -> fun baz -> Foo.bar baz)
 let bump_list (type a) =
   Function$
     (fun [arity:2]((module B)  : (module Bumpable with type t = a)) ->
-       fun [arity:1](l : a list) ->
-         List.map ~f:((B.bump l)[@res.namedArgLoc ]))
+       fun (l : a list) -> List.map ~f:((B.bump l)[@res.namedArgLoc ]))
 ;;match x with
   | (module Set)  -> ()
   | ((module Set)  : (module Set.S with type elt = s)) -> ()
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/polyvariants.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/polyvariants.res.txt
index 8b18583c4b..f9342b085d 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/polyvariants.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/polyvariants.res.txt
@@ -70,7 +70,7 @@ let f =
 let cmp =
   Function$
     (fun [arity:2]selectedChoice ->
-       fun [arity:1]value ->
+       fun value ->
          match (selectedChoice, value) with
          | (#a, #a) -> true
          | [|#b;#b|] -> true
diff --git a/tests/syntax_tests/data/parsing/grammar/pattern/expected/unit.res.txt b/tests/syntax_tests/data/parsing/grammar/pattern/expected/unit.res.txt
index f1d3f48961..600c1ab974 100644
--- a/tests/syntax_tests/data/parsing/grammar/pattern/expected/unit.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/pattern/expected/unit.res.txt
@@ -29,8 +29,8 @@ let (() : unit) as x = ()
 let f = Function$ (fun [arity:1]() -> ())
 let f = Function$ (fun [arity:1]() -> ())
 let f = Function$ (fun [arity:1](() as _u) -> ())
-let f = Function$ (fun [arity:2]() -> fun [arity:1]() -> ())
-let f = Function$ (fun [arity:2](() as _u) -> fun [arity:1](() as _u) -> ())
+let f = Function$ (fun [arity:2]() -> fun () -> ())
+let f = Function$ (fun [arity:2](() as _u) -> fun (() as _u) -> ())
 let f = Function$ (fun [arity:1](() : unit) -> ())
 let f = Function$ (fun [arity:1]((() as _u) : unit) -> ())
 let f = Function$ (fun [arity:1]((() : unit) as _u) -> ())
diff --git a/tests/syntax_tests/data/parsing/infiniteLoops/expected/equalAfterBinaryExpr.res.txt b/tests/syntax_tests/data/parsing/infiniteLoops/expected/equalAfterBinaryExpr.res.txt
index 6e2dbf6a62..2a06ff2c95 100644
--- a/tests/syntax_tests/data/parsing/infiniteLoops/expected/equalAfterBinaryExpr.res.txt
+++ b/tests/syntax_tests/data/parsing/infiniteLoops/expected/equalAfterBinaryExpr.res.txt
@@ -13,7 +13,7 @@
 let rec _addLoop =
   Function$
     (fun [arity:2]rbt ->
-       fun [arity:1]currentNode ->
+       fun currentNode ->
          ((if (Some currentNode) == (rbt |.u root)
            then currentNode.color <- Black
            else
@@ -64,7 +64,7 @@ let rec _addLoop =
 let removeNode =
   Function$
     (fun [arity:2]rbt ->
-       fun [arity:1]node ->
+       fun node ->
          ((if nodeToRemove.color == Black
            then
              (if successor.color == Red
diff --git a/tests/syntax_tests/data/parsing/infiniteLoops/expected/nonRecTypes.res.txt b/tests/syntax_tests/data/parsing/infiniteLoops/expected/nonRecTypes.res.txt
index b45c9d086d..f690cecfef 100644
--- a/tests/syntax_tests/data/parsing/infiniteLoops/expected/nonRecTypes.res.txt
+++ b/tests/syntax_tests/data/parsing/infiniteLoops/expected/nonRecTypes.res.txt
@@ -128,13 +128,13 @@ include
     let has =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]value -> (_findNode rbt (rootGet rbt) value) != None)
+           fun value -> (_findNode rbt (rootGet rbt) value) != None)
     let rec minNode = Function$ (fun [arity:1]node -> [%rescript.exprhole ])
     let findMin = Function$ (fun [arity:1]rbt -> [%rescript.exprhole ])
     let removeNode =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]node ->
+           fun node ->
              ((let nodeToRemove =
                  match ((leftGet node), (rightGet node)) with
                  | (Some _, Some _) ->
@@ -315,7 +315,7 @@ include
     let remove =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]value ->
+           fun value ->
              match _findNode rbt (rootGet rbt) value with
              | Some node ->
                  (removeNode rbt node;
@@ -325,12 +325,12 @@ include
     let findThroughCallback =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]cb ->
+           fun cb ->
              ((let rec findThroughCallback =
                  Function$
                    (fun [arity:3]rbt ->
-                      fun [arity:2]node ->
-                        fun [arity:1]cb ->
+                      fun node ->
+                        fun cb ->
                           match node with
                           | None -> None
                           | Some node ->
@@ -356,9 +356,9 @@ include
     let rec heightOfInterval =
       Function$
         (fun [arity:4]rbt ->
-           fun [arity:3]node ->
-             fun [arity:2]lhs ->
-               fun [arity:1]rhs ->
+           fun node ->
+             fun lhs ->
+               fun rhs ->
                  match node with
                  | None -> 0.
                  | Some n ->
@@ -385,12 +385,11 @@ include
     let heightOfInterval =
       Function$
         (fun [arity:3]rbt ->
-           fun [arity:2]lhs ->
-             fun [arity:1]rhs -> heightOfInterval rbt (rootGet rbt) lhs rhs)
+           fun lhs -> fun rhs -> heightOfInterval rbt (rootGet rbt) lhs rhs)
     let rec firstVisibleNode =
       Function$
         (fun [arity:2]node ->
-           fun [arity:1]offset ->
+           fun offset ->
              match node with
              | None -> None
              | Some node ->
@@ -413,14 +412,14 @@ include
     let lastVisibleNode =
       Function$
         (fun [arity:2]node ->
-           fun [arity:1]offset ->
+           fun offset ->
              match firstVisibleNode node offset with
              | None -> maxNode node
              | first -> first)
     let firstVisible =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]~offset:((offset)[@res.namedArgLoc ]) ->
+           fun ~offset:((offset)[@res.namedArgLoc ]) ->
              match firstVisibleNode (rootGet rbt) offset with
              | None -> None
              | Some node -> Some (valueGet node))
@@ -446,8 +445,7 @@ include
     let rec sumLeftSpine =
       Function$
         (fun [arity:2]node ->
-           fun [arity:1]~fromRightChild:((fromRightChild)[@res.namedArgLoc ])
-             ->
+           fun ~fromRightChild:((fromRightChild)[@res.namedArgLoc ]) ->
              ((let leftSpine =
                  match leftGet node with
                  | None -> heightGet node
@@ -471,11 +469,11 @@ include
     let linearSearch =
       Function$
         (fun [arity:2]rbt ->
-           fun [arity:1]callback ->
+           fun callback ->
              ((let rec find =
                  Function$
                    (fun [arity:2]node ->
-                      fun [arity:1]callback ->
+                      fun callback ->
                         if Js.Internal.fn_run1 callback (valueGet node)
                         then Some (valueGet node)
                         else
@@ -489,9 +487,9 @@ include
     let rec iterate =
       Function$
         (fun [arity:4]~inclusive:((inclusive)[@res.namedArgLoc ]) ->
-           fun [arity:3]firstNode ->
-             fun [arity:2]lastNode ->
-               fun [arity:1]~callback:((callback)[@res.namedArgLoc ]) ->
+           fun firstNode ->
+             fun lastNode ->
+               fun ~callback:((callback)[@res.namedArgLoc ]) ->
                  match firstNode with
                  | None -> ()
                  | Some node ->
@@ -506,10 +504,10 @@ include
     let rec iterateWithY =
       Function$
         (fun [arity:5]?y:((y)[@res.namedArgLoc ]) ->
-           fun [arity:4]~inclusive:((inclusive)[@res.namedArgLoc ]) ->
-             fun [arity:3]firstNode ->
-               fun [arity:2]lastNode ->
-                 fun [arity:1]~callback:((callback)[@res.namedArgLoc ]) ->
+           fun ~inclusive:((inclusive)[@res.namedArgLoc ]) ->
+             fun firstNode ->
+               fun lastNode ->
+                 fun ~callback:((callback)[@res.namedArgLoc ]) ->
                    match firstNode with
                    | None -> ()
                    | Some node ->
@@ -526,7 +524,7 @@ include
     let rec updateSum =
       Function$
         (fun [arity:2]node ->
-           fun [arity:1]~delta:((delta)[@res.namedArgLoc ]) ->
+           fun ~delta:((delta)[@res.namedArgLoc ]) ->
              match node with
              | None -> ()
              | Some node ->
@@ -536,8 +534,8 @@ include
     let setHeight =
       Function$
         (fun [arity:3]rbt ->
-           fun [arity:2]value ->
-             fun [arity:1]~height:((height)[@res.namedArgLoc ]) ->
+           fun value ->
+             fun ~height:((height)[@res.namedArgLoc ]) ->
                match _findNode rbt (rootGet rbt) value with
                | None -> ()
                | Some node ->
diff --git a/tests/syntax_tests/data/parsing/recovery/expression/expected/emptyBlock.res.txt b/tests/syntax_tests/data/parsing/recovery/expression/expected/emptyBlock.res.txt
index b08fdd7412..fca8935cc9 100644
--- a/tests/syntax_tests/data/parsing/recovery/expression/expected/emptyBlock.res.txt
+++ b/tests/syntax_tests/data/parsing/recovery/expression/expected/emptyBlock.res.txt
@@ -1,2 +1,2 @@
 let x = {  }
-let f = Function$ (fun [arity:2]a -> fun [arity:1]b -> {  })
\ No newline at end of file
+let f = Function$ (fun [arity:2]a -> fun b -> {  })
\ No newline at end of file