Re: Buffered input for a lexer?

Randall Hyde wrote:
> Like GCC and a few other compilers, I require that the source file end
> with a newline (actually, any whitespace or single character lexeme
> would be fine, but I explicitly check for a newline after mapping the
> file and warn the user if one isn't present (*). If a newline is
> present, then I don't have to check for the end of the buffer except
> when scanning whitespace.


Is there a deep reason for doing it this way? I mean, it wouldn't be
too difficult to check for end-of-file. Just let the routine that gets
the next character check whether it's past EOF, in which case it
returns a line feed. (Or a special EOF character that's handled mostly
like a line feed, except that it also ends the scanning process.) If
you're doing memory-mapped IO, the EOF check is just a pointer
comparison.


So: what did I overlook?


Regards,
Joachim

Return to the comp.compilers page.
Search the comp.compilers archives again.