Is the dot operator now obsolete in C?

smeezekitty · 11-03-2009, 12:52 PM

atleast they dont do it the WTF way!:

Code:

void cats(smeeze, tina)
cat *smeeze;
cat *tina;
{
}

TURBO C++ gives a warning: Style of function defininition is now obsolete.
now if its obsolete in 1991 it is very obsolete now.

JohnGraham · 11-04-2009, 03:29 AM

Quote:

Originally Posted by xhypno

White space is not a delimiter in c or c++ unless you overload it so your comment about void being on a different line is completely incorrect.

You can overload whitespace? Really? If you can, please tell us how!

John G

xhypno · 11-04-2009, 10:29 AM

Quote:

Originally Posted by JohnGraham

You can overload whitespace? Really? If you can, please tell us how!

John G

Here you go.

http://www2.research.att.com/~bs/whitespace98.pdf

It is a good paper from Stroustrup the creator of C++. I first read it in paper form in my hard back copy of The C++ Programming Language and used it a few times since for really odd ball problems.

tuxdev · 11-04-2009, 10:44 AM

Uh, that's non-standard, and completely different from what smeezekitty was talking about. I hope that *never* shows up in C++, it trades an easy parse error for a nasty missing operator error. Also it's a lot less clear because it breaks the ingrained training of C's lexing and grammar rules.

smeezekitty · 11-04-2009, 11:46 AM

Overload whitespace? i think not.

xhypno · 11-04-2009, 01:08 PM

Quote:

Originally Posted by tuxdev

Uh, that's non-standard, and completely different from what smeezekitty was talking about. I hope that *never* shows up in C++, it trades an easy parse error for a nasty missing operator error. Also it's a lot less clear because it breaks the ingrained training of C's lexing and grammar rules.

News flash, this is in c also as it is what is used to create lex'ed combo operators for Logic.

And the comment to Smeeze was about his incorrect statement that the return type being on the line above the rest of the function def was wrong as white space doesn't delimit code in c or c++.

xhypno · 11-04-2009, 01:09 PM

Quote:

Originally Posted by smeezekitty

Overload whitespace? i think not.

And again you show that your thinking is wrong.

jlliagre · 11-04-2009, 01:30 PM

Hmm, did anyone notice Stroustrup's whitespace overloading paper was an April fool joke ?

xhypno · 11-04-2009, 01:32 PM

Quote:

Originally Posted by jlliagre

Hmm, did anyone notice Stroustrup's whitespace overloading paper was an April fool joke ?

funny thing is that is how it started and ended up in the ISO99 standard for c and c++

tuxdev · 11-04-2009, 01:59 PM

Quote:

Hmm, did anyone notice Stroustrup's whitespace overloading paper was an April fool joke ?

Oh yeah.. totally missed that. Haha, it's almost plausible enough to actually be serious. I really should have checked when he started mentioning Unicode characters..

Quote:

funny thing is that is how it started and ended up in the ISO99 standard for c and c++

That's blatantly wrong, overloading whitespace is definitely non-standard, especially the non-context-free lex extension (actually, good lex rules are regular expressions, but I'm being lax here). If you really want to prove it otherwise, write an example that'll compile in Comeau.

smeezekitty · 11-04-2009, 02:09 PM

even if you did overload whitespace all code after it would have errors for example:

Code:

/*overload whitespace here*/
int main(){
   ^                     |-Parse error
   |-Parse error         V
printf("Hello world! %d", 123);
        |-- Parse error
        V
unsigned j=0;
return(j);
}

tuxdev · 11-04-2009, 02:25 PM

Those locations wouldn't cause parse errors - the whitespace operator would be an r-value expression.

smeezekitty · 11-04-2009, 02:38 PM

i tried it:
turbo C++ errors:

Code:

 Compiling OW.CPP:
•Error OW.CPP 2: Overloadable operator expected
 Error OW.CPP 2: Declaration terminated incorrectly

GNU CC

Code:

ow.cpp:2: error: expected identifier before '\x20'
ow.cpp: In function `int main()':
ow.cpp:4: error: expected `)' before numeric constant
ow.cpp:5:2: warning: no newline at end of file

CODE:

Code:

#include <stdio.h>
double operator ' '(double d1, double d2) { return d1*d2; }
int main(){
printf("%d", 2 2);
}

ta0kira · 11-04-2009, 05:43 PM

Quote:

Originally Posted by jlliagre

Hmm, did anyone notice Stroustrup's whitespace overloading paper was an April fool joke ?

I have to admit, the first time I read that a few years ago I was halfway through writing a post about how preposterous the idea was by the time read the "April fools" part...
Kevin Barry

PS On the other hand, one would think overloading operator , would be just as ridiculous, yet it's perfectly valid...

ta0kira · 11-04-2009, 05:46 PM

Quote:

Originally Posted by xhypno

funny thing is that is how it started and ended up in the ISO99 standard for c and c++

What? Do you have a reference? And I don't mean "C99"; do you have a section/paragraph in mind?
Kevin Barry