Re: C syntax, and spurious semicolons

Seriously advanced syntax code, that :-)! That seems to work very
well. Consequential errors show up as well, braces and semicolons
showing up as red, so fixing the first erroneous semicolon clears a
lot of red later. This helps in finding the culprit, so that isn't
a problem. The only thing now is that I'm getting the ; in for
loops showing up as red, when the rest is cleared by fixing the
syntax.

for(k=0;k<mk;k++)
{
...
}

Any ideas about that?
Thank you,
Hugh

On Tue, 22 Feb 2011, Ben Schmidt wrote:

> On 22/02/11 1:23 AM, Hugh Sasse wrote:
> > I've been assisting a colleague with their C code, and he has
> > learned to add semicolons at the end of statements too well. His
> > current favourite mistake is to write
> > if (expression == value);
> > {
> > do_something();
> > };
>
> O nooo!!!
>
> > I frequently miss the trailing semicolon on the first line. So I
> > was wondering if it would make sense to modify the C syntax file to
> > highlight
> > if (expr);
> > such that the semicolon shows up as an error. Clearly it is a legal
> > null statement, and so is syntactically correct. But if one only
> > wanted the expr for its side effects, one would not need to put it
> > in an if. To do this because one is only using the else part is
> > poor communication with other programmers.
>
> I agree nobody should ever do this, even though it's valid.
>
> > Is there a good reason not to change the syntax file? Otherwise,
> > can anyone suggest a patch: my skills in this area are suboptimal,
> > as I don't change syntax files very often.
>
> It's a relatively complicated change, because the syntax file currently
> doesn't recognise the if as a construct; it only recognises if as a
> keyword and treats the parentheses just as any other set of parentheses.
>
> This code seems to work for me to get it to recognise the construct and
> call the empty-statement semi-colon an error; it also highlights the
> parentheses of the if as a keyword, as a side-effect. You can put it in
> ~/.vim/after/syntax/c.vim (or on Windows,
> $HOME/vimfiles/after/syntax/c.vim) and it should work.
>
> syn clear cConditional
> syn keyword cConditional else switch
> syn region cIf matchgroup=cConditional start=+if\_s*(+
> end=+)\_s*\ze[^;)]+ contains=ALLBUT,@cParenGroup,cCppParen,cCppString,@Spell
> skipwhite skipnl skipempty nextgroup=cSemiError
> syn match cSemiError contained ";"
> hi link cSemiError cParenError
>
> Not sure that it's a good idea for the distributed Vim C syntax file,
> though. It may slow down the matching, possibly, and there may be a
> bunch of corner cases that don't work so well, and other usability
> glitches while you're writing code (before the syntax is valid). I guess
> it depends if others would find this useful, and whether there are
> noticable hassles with it or not. Maybe try it out and get back to us if
> you think it would be worth including (Bram is the maintainer of the C
> syntax, so he's the person you'd need to convince!).
>
> Ben.
>
>
>
> --
> You received this message from the "vim_use" maillist.
> Do not top-post! Type your reply below the text you are replying to.
> For more information, visit http://www.vim.org/maillist.php
>

--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php