---input---
(define* (foo #:key (bar123? 'baz))
  (display bar123?)
  (newline))

(foo #:bar123? 'xyz)

---tokens---
'('           Punctuation
'define*'     Keyword
' '           Text.Whitespace
'('           Punctuation
'foo'         Name.Function
' '           Text.Whitespace
'#:key'       Keyword.Declaration
' '           Text.Whitespace
'('           Punctuation
'bar123?'     Name.Function
' '           Text.Whitespace
"'baz"        Literal.String.Symbol
')'           Punctuation
')'           Punctuation
'\n  '        Text.Whitespace
'('           Punctuation
'display'     Name.Builtin
' '           Text.Whitespace
'bar123?'     Name.Variable
')'           Punctuation
'\n  '        Text.Whitespace
'('           Punctuation
'newline'     Name.Builtin
')'           Punctuation
')'           Punctuation
'\n\n'        Text.Whitespace

'('           Punctuation
'foo'         Name.Function
' '           Text.Whitespace
'#:bar123?'   Keyword.Declaration
' '           Text.Whitespace
"'xyz"        Literal.String.Symbol
')'           Punctuation
'\n'          Text.Whitespace
