scalaparse: ! and ~ cannot be parsed as object names

[abgruszecki]

Examples from Ammonite:

@ object !
defined object !

@ // Here I would write just !, but Ammonite doesn't actually allow entering that

@ !.toString
SyntaxError: found "!.toString", expected Import | Prelude ~ BlockDef | Expr | "{" | End at index 0
!.toString
^

@ {{ !.toString }}
SyntaxError: found "!.toString }}", expected ";" | Newline.rep(1) | "}" at index 3
{{ !.toString }}
   ^

@ val a = !.toString
SyntaxError: found "!.toString", expected If | While | Try | DoWhile | For | Throw | Return | ImplicitLambda | SmallerExprOrLambda at index 8
val a = !.toString
        ^

@ `!`
res1: !.type = ammonite.$sess.cmd0$$bang$@39ae6408

Same goes for ~.

For comparison, scala behaviour:

scala> object !
defined object $bang

scala> !
res2: !.type = $bang$@40d23c82

scala> !.toString
res3: String = $bang$@40d23c82

scala> object ~
defined object $tilde

scala> ~
res4: ~.type = $tilde$@29170a47