Re: How to tell the difference bewteen comparing and assigning
- Posted by jbrown105 at speedymail.org May 12, 2002
- 434 views
On 0, stabmaster_ at HOTMAIL.COM wrote: > > One way to spot comparisons (although it probably doesn't cover _all_ > possible comparisons) are when '=' is used after 'if' or 'while' > > if 1=0 then... > > while 0=1 do... > > etc. > Aside from not covering all situations, what do i do about this: if a > b then a = b else b = a end if i could try looking only between the "if" and "then" tokens (and ditto for while..do) but it would be hard to do that for all possible situations: ?(a=b) --check for ( ?a[b=b] --check for [ ? a=b --check for ? a = a = b --check for previous = etc etc etc as there are too many exceptions and to make a parser which takes care of this cleanly would be quite difficult. i was thinking about making my preprocessor use == for comparision and := for assignment and ignore the = sign completely. (Perhaps even make the = sign an illegal token, although that would be going to the extreme.) I'd prefer not to do that however, so if you or anyone else has an idea on how this could be done, it would be greatly appreciated. TIA, jbrown -- http://fastmail.fm Quick as a click