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D - scope of variables in do-while

reply "Robert" <no spam.ne.jp> writes:
I sometimes want to write as:

do {
    int c = getchar();
} while(!(c == EOF || c == '\n'));

but condition expression of the 'while' is out of scope of 'c'.
So, I must write as:

int c;
do {
    c = getchar();
} while(!(c == EOF || c == '\n'));

Though, I think the former is better than the latter.
Jan 07 2004
next sibling parent reply Ilya Minkov <minkov cs.tum.edu> writes:
I vote for it! I just ran over the same in C++ today!

do scope should extend to while.

Robert wrote:

 do {
     int c = getchar();
 } while(!(c == EOF || c == '\n'));
Jan 07 2004
parent "Sean L. Palmer" <palmer.sean verizon.net> writes:
Yes.  I often wish for this.

Sean

"Ilya Minkov" <minkov cs.tum.edu> wrote in message
news:bthssm$2s00$1 digitaldaemon.com...

 I vote for it! I just ran over the same in C++ today!

 do scope should extend to while.

 Robert wrote:

 do {
     int c = getchar();
 } while(!(c == EOF || c == '\n'));
Jan 11 2004
prev sibling next sibling parent reply Tony West <Tony_member pathlink.com> writes:
I've had the same problem and yes, it would be nice for the scope to extend to
the while expression.

I would imagine that this is not normally supported because of the possibility
that an identifier may be redefined within an inner block, e.g.

int a;
do
{
int a;
blah...
}while (a == 1);

Which "a" is referenced within the while expression?

Fortunately, since D does not allow multiple definitions, this should not be an
issue.

Tony
Jan 07 2004
parent Ilya Minkov <minkov cs.tum.edu> writes:
Tony West wrote:

 int a;
 do
 {
 int a;
 blah...
 }while (a == 1);


Such a loop is a nonsense anyway, since it either loops only once, or 
never stops, depending on the value of outermost a. That's most probably 
not what the average coder wants when he writes that.

-eye
Jan 07 2004
prev sibling next sibling parent "Matthew" <matthew.hat stlsoft.dot.org> writes:
How about

do with (int c)
{
    c = getchar();
} while(!(c == EOF || c == '\n'));


Walter, would that be unambiguously parseable?


"Robert" <no spam.ne.jp> wrote in message
news:bthsbo$2raj$1 digitaldaemon.com...

 I sometimes want to write as:

 do {
     int c = getchar();
 } while(!(c == EOF || c == '\n'));

 but condition expression of the 'while' is out of scope of 'c'.
 So, I must write as:

 int c;
 do {
     c = getchar();
 } while(!(c == EOF || c == '\n'));

 Though, I think the former is better than the latter.
Jan 07 2004
prev sibling next sibling parent reply Heretic <Heretic_member pathlink.com> writes:
In article <bthsbo$2raj$1 digitaldaemon.com>, Robert says...

I sometimes want to write as:

do {
    int c = getchar();
} while(!(c == EOF || c == '\n'));


I also vote ;) for this... i wish it was this way everytime i write a do-while
loop :)
Jan 07 2004
parent "Sean L. Palmer" <palmer.sean verizon.net> writes:
while is somewhat ambiguous anyway.  Why not go ahead and add until?

{
    int c=getchar();
} until (c > 32);

Or it could also start with do

do { } until (false);

Just prevents a bit of logical negation, may make some source code a wee bit
clearer in intent.

Sean

"Heretic" <Heretic_member pathlink.com> wrote in message
news:bti7kf$bou$1 digitaldaemon.com...

 In article <bthsbo$2raj$1 digitaldaemon.com>, Robert says...

I sometimes want to write as:

do {
    int c = getchar();
} while(!(c == EOF || c == '\n'));


 I also vote ;) for this... i wish it was this way everytime i write a


do-while

 loop :)
Jan 11 2004
prev sibling parent J Anderson <REMOVEanderson badmama.com.au> writes:
Robert wrote:


I sometimes want to write as:

do {
    int c = getchar();
} while(!(c == EOF || c == '\n'));

but condition expression of the 'while' is out of scope of 'c'.
So, I must write as:

int c;
do {
    c = getchar();
} while(!(c == EOF || c == '\n'));

Though, I think the former is better than the latter.

  


I like this idea. It could also apply to the last parameter in a for
loop, but that's a bit picky.
Jan 07 2004