PHP-style (embedded variables) print statements

[Lars Ivar Igesund]

Don Clugston wrote:

> Jarrett Billingsley wrote:
>> "Don Clugston" <dac at nospam.com.au> wrote in message
>> news:f3lt8d$2je5$1 at digitalmars.com...
>>> Note that unlike a tuple solution, it does not cause any template bloat.
>>> Also doesn't have some of writefln's pitfalls (the case where a string
>>> contains a % character).
>> 
>> You can't print out the string using %s?
> 
> The problem is that it's so easy to forget the %s, and have a latent bug
> that lies undetected.
> 
>> 
>>> Opinions? Is something like this worth considering as an alternative to
>>> writefln, and to Tango's C# formatting and whisper syntax?
>> 
>> Not to burst your bubble, but I've just never found variable
>> interpolation to be all that useful, mostly because it's not really
>> obvious (unless you have some kind of fancy code highlighter) when
>> something's being interpolated, and because there's already syntaxes that
>> look fine to me. Some people like it though.
> 
> Yes, these are the main issues. I know that people have requested it in
> the past (and it was also touted as something Nemerle can do which D can't
> <g>). Personally, I thought it was one of very few interesting features of
> PHP.
> 
> There's probably a syntax which would be a bit more obvious, but still...
> BTW, do you feel the same way about the C# syntax? Is it obvious enough?
> 
> mixin interpolation:
>    mixin(dprint("current=$i next=$(i+1) const=$(k*3) $str"));
> 
> C# (available in Tango):
>    print("current={0} next={1} const={2} {3}", i, i+1, k+3, str));

To compare, you should use

     Stdout("current=")(i)(" next=")(i+1)(" const=")(k*3)(" ")(str);

Since I'm not too happy about $vars , I would find it more interesting if it
was

   mixin(dprint("current={i} next={i+1,5} const={k*3:C} {str}));

which would allow for the specifiers in the C# format, like padding (,5) or
print as currency (:C). Even more interesting would be to use Sprint to
make it usable in logging.

Would have to get rid of the mixin, though :)

-- 
Lars Ivar Igesund
blog at http://larsivi.net
DSource, #d.tango & #D: larsivi
Dancing the Tango