(* TEST
 expect;
*)

let f o x = o##x;;
[%%expect {|
Line 1, characters 13-15:
1 | let f o x = o##x;;
                 ^^
Error: "##" is not a valid value identifier.
|}]

let f x = !#x
[%%expect {|
Line 1, characters 10-12:
1 | let f x = !#x
              ^^
Error: "!#" is not a valid value identifier.
|}]

let f x = ?#x
[%%expect {|
Line 1, characters 10-12:
1 | let f x = ?#x
              ^^
Error: "?#" is not a valid value identifier.
|}]

let f x = ~#x
[%%expect {|
Line 1, characters 10-12:
1 | let f x = ~#x
              ^^
Error: "~#" is not a valid value identifier.
|}]

let f o x = o#-#x
[%%expect {|
Line 1, characters 13-16:
1 | let f o x = o#-#x
                 ^^^
Error: "#-#" is not a valid value identifier.
|}]

let f x = !-#x
[%%expect {|
Line 1, characters 10-13:
1 | let f x = !-#x
              ^^^
Error: "!-#" is not a valid value identifier.
|}]

let f x = ?-#x
[%%expect {|
Line 1, characters 10-13:
1 | let f x = ?-#x
              ^^^
Error: "?-#" is not a valid value identifier.
|}]

let f x = ~-#x
[%%expect {|
Line 1, characters 10-13:
1 | let f x = ~-#x
              ^^^
Error: "~-#" is not a valid value identifier.
|}]