Can someone clear this up for me?  The following code doesn't work the way that I would expect from the description of slices.


int main()
{
  char[] one = "abc\ndef\n";
  char[] two = one[0..3];
  printf( "%s\n", cast(char *) one );
  return( 0 );
}

generates as output

  abc
  def

instead of just
  abc

"Steve Adams" <adamss@ascinet.com> wrote in message news:b58ekm$1kqe$1@digitaldaemon.com...
> Can someone clear this up for me?  The following code doesn't work the way that I would expect from the description of slices.
>
>
> int main()
> {
>   char[] one = "abc\ndef\n";
>   char[] two = one[0..3];
>   printf( "%s\n", cast(char *) one );
>   return( 0 );
> }
>
> generates as output
>
>   abc
>   def
>
> instead of just
>   abc
>

Seems correct output to me...

Now it may have your expected output if you did:

printf("%s\n", cast(char *) two);

Am I missing something?

Later,
John

Sigh.  The printf line should be:

  printf( "%s\n", case(char *)two);


"Steve Adams" <adamss@ascinet.com> wrote in message news:b58ekm$1kqe$1@digitaldaemon.com...
> Can someone clear this up for me?  The following code doesn't work the way that I would expect from the description of slices.
>
>
> int main()
> {
>   char[] one = "abc\ndef\n";
>   char[] two = one[0..3];
>   printf( "%s\n", cast(char *) one );
>   return( 0 );
> }
>
> generates as output
>
>   abc
>   def
>
> instead of just
>   abc
>
>
>

:-)

"Steve Adams" <adamss@ascinet.com> wrote in message news:b58fm5$1lke$1@digitaldaemon.com...
> Sigh.  The printf line should be:
>
>   printf( "%s\n", case(char *)two);
>
>

Nothing like hitting send too soon.

But, it still doesn't work.  It always prints all the characters in one.


"John Reimer" <jjreimer@telus.net> wrote in message news:b58fs0$1lm4$1@digitaldaemon.com...
> :-)
>
> "Steve Adams" <adamss@ascinet.com> wrote in message news:b58fm5$1lke$1@digitaldaemon.com...
> > Sigh.  The printf line should be:
> >
> >   printf( "%s\n", case(char *)two);
> >
> >
>
>

Well, I think the reason is because you've taken a slice of array one and put it in two, and two doesn't have a null terminator in it's slice by default, so you end up printing until there's a null termination of the string which, it appears, is in the same address as the string termination of one..

I didn't realize, though, that a slice seems to be like a pointer to variable one's memory space, if indeed it has the output you say. Or maybe it copies the whole string, but only represents the slice.

A convoluted way of saying it, I'm sure... but I think that's the problem.

Later,
John

"Steve Adams" <adamss@ascinet.com> wrote in news:b58g2f$1lo7$1@digitaldaemon.com:

> Nothing like hitting send too soon.
> 
> But, it still doesn't work.  It always prints all the characters in one.
> 
> 
> "John Reimer" <jjreimer@telus.net> wrote in message news:b58fs0$1lm4$1@digitaldaemon.com...
>> :-)
>>
>> "Steve Adams" <adamss@ascinet.com> wrote in message news:b58fm5$1lke$1@digitaldaemon.com...
>> > Sigh.  The printf line should be:
>> >
>> >   printf( "%s\n", case(char *)two);

This is a very common mistake.  D strings are
not null terminated, except for the constant
ones defined inline.  Try this instead.

printf("%.*s\n",two);

Seems like it's a pointer and a count (since strings are counted).  Not a
bad model, until
you want to print it out.  I'm working around it with

  printf( "%.*s\n", two.length, (char *)two );

but that seems rather wasteful.  Either the cast should really do a case, or
there should be
a format specifier for the counted strings.

Might be a way to do this with an array copy too I suppose.


"John Reimer" <jjreimer@telus.net> wrote in message news:b58gmo$1m3a$1@digitaldaemon.com...
> Well, I think the reason is because you've taken a slice of array one and put it in two, and two doesn't have a null terminator in it's slice by default, so you end up printing until there's a null termination of the string which, it appears, is in the same address as the string termination of one..
>
> I didn't realize, though, that a slice seems to be like a pointer to variable one's memory space, if indeed it has the output you say. Or maybe it copies the whole string, but only represents the slice.
>
> A convoluted way of saying it, I'm sure... but I think that's the problem.
>
> Later,
> John
>
>

> This is a very common mistake.  D strings are
> not null terminated, except for the constant
> ones defined inline.  Try this instead.
>
> printf("%.*s\n",two);
>
>

Ah, now there's a good answer :-)

Thanks cleaner.  Thanks.


> >> news:b58fm5$1lke$1@digitaldaemon.com...
> >> > Sigh.  The printf line should be:
> >> >
> >> >   printf( "%s\n", case(char *)two);
>
> This is a very common mistake.  D strings are
> not null terminated, except for the constant
> ones defined inline.  Try this instead.
>
> printf("%.*s\n",two);
>
>
>