Improve error messages for function arity errors (rescript-lang#6990)

* Improve some error texts ("uncurried function" -> "function")

* CHANGELOG

Author: cknitt

CHANGELOG.md

@@ -120,6 +120,7 @@
 - Fix `Js.Types.JSBigInt` payload to use native `bigint` type. https://github.com/rescript-lang/rescript-compiler/pull/6911
 - Deprecate `%external` extension, which has never been officially introduced. https://github.com/rescript-lang/rescript-compiler/pull/6906
 - Deprecate `xxxU` functions in Belt. https://github.com/rescript-lang/rescript-compiler/pull/6941
+- Improve error messages for function arity errors. https://github.com/rescript-lang/rescript-compiler/pull/6990
 
 # 11.1.3
 

jscomp/build_tests/super_errors/expected/arity_mismatch.res.expected

@@ -6,5 +6,5 @@
   2 │ let makeVariables = makeVar(.~f=f => f)
   3 │ 
 
-  This uncurried function has type (~f: 'a => 'a, unit) => int
+  This function has type (~f: 'a => 'a, unit) => int
   It is applied with 1 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/arity_mismatch2.res.expected

@@ -6,5 +6,5 @@
   2 │ let makeVariables = makeVar(. 1, 2, 3)
   3 │ 
 
-  This uncurried function has type ('a, unit) => int
+  This function has type ('a, unit) => int
   It is applied with 3 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/method_arity_mismatch.res.expected

@@ -8,5 +8,5 @@
   4 │ }
   5 │ 
 
-  This uncurried function has type (int, int) => unit
+  This function has type (int, int) => unit
   It is applied with 1 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/moreArguments1.res.expected

@@ -6,5 +6,5 @@
   2 │ let y = x(~a=2) + 2
   3 │ 
 
-  This uncurried function has type (~a: int, ~b: int) => int
+  This function has type (~a: int, ~b: int) => int
   It is applied with 1 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/moreArguments2.res.expected

@@ -6,5 +6,5 @@
   2 │ let y = x(2) + 2
   3 │ 
 
-  This uncurried function has type (int, int) => int
+  This function has type (int, int) => int
   It is applied with 1 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/moreArguments3.res.expected

@@ -6,5 +6,5 @@
   2 │ let y = x(2) + 2
   3 │ 
 
-  This uncurried function has type (int, int, 'a, 'b) => int
+  This function has type (int, int, 'a, 'b) => int
   It is applied with 1 arguments but it requires 4.

jscomp/build_tests/super_errors/expected/moreArguments4.res.expected

@@ -6,5 +6,5 @@
   2 │ let y = x(2) + 2
   3 │ 
 
-  This uncurried function has type (int, ~b: int, ~c: 'a, ~d: 'b) => int
+  This function has type (int, ~b: int, ~c: 'a, ~d: 'b) => int
   It is applied with 1 arguments but it requires 4.

jscomp/build_tests/super_errors/expected/moreArguments5.res.expected

@@ -7,5 +7,5 @@
   5 │ let y = x(2).Sub.a
   6 │ 
 
-  This uncurried function has type (int, 'a, 'b, 'c) => Sub.a
+  This function has type (int, 'a, 'b, 'c) => Sub.a
   It is applied with 1 arguments but it requires 4.

jscomp/build_tests/super_errors/expected/partial_app.res.expected

@@ -7,5 +7,5 @@
   5 │ f(1, 2)
   6 │ 
 
-  This uncurried function has type (int, int, int) => int
+  This function has type (int, int, int) => int
   It is applied with 2 arguments but it requires 3.

jscomp/build_tests/super_errors/expected/primitives3.res.expected

@@ -7,5 +7,5 @@
   3 │ x(2, 4)
   4 │ 
 
-  This uncurried function has type int => int
+  This function has type int => int
   It is applied with 2 arguments but it requires 1.

jscomp/build_tests/super_errors/expected/recursive_type.res.expected

@@ -8,6 +8,6 @@
   36 │   assert(false)
   37 │ }
 
-  This uncurried function has type
+  This function has type
     ((option<'a>, ([> #List(list<'b>)] as 'b)) => 'c, 'd) => 'c
   It is applied with 1 arguments but it requires 2.

jscomp/build_tests/super_errors/expected/warnings1.res.expected

@@ -8,5 +8,5 @@
   4 │   10
   5 │ }
 
-  This uncurried function has type (int, int) => int
+  This function has type (int, int) => int
   It is applied with 1 arguments but it requires 2.

jscomp/ml/typecore.ml

@@ -4011,7 +4011,7 @@ let report_error env ppf = function
   | Empty_record_literal ->
       fprintf ppf  "Empty record literal {} should be type annotated or used in a record context."
   | Uncurried_arity_mismatch (typ, arity, args) ->
-    fprintf ppf "@[<v>@[<2>This uncurried function has type@ %a@]"
+    fprintf ppf "@[<v>@[<2>This function has type@ %a@]"
       type_expr typ;
     fprintf ppf "@ @[It is applied with @{<error>%d@} argument%s but it requires @{<info>%d@}.@]@]"
       args (if args = 0 then "" else "s") arity