Tokens
are sequences of printable ASCII characters delimited by white space,
except that `(', `)', `[', `]',
`{', `}', and `,' are always considered as single
character tokens, unless backquoted.
Single line comments are started by one of *** or --, and ended by the end of line. Multiline comments are started by ***( and ended by ). Parentheses (whether backquoted or not) must balance within multiline comments.
String identifiers use C backslash conventions [47, Section A2.5.2].