phobos / tango / ares

Johan Granberg lijat.meREM at OVE.gmail.com
Thu Feb 8 23:32:37 PST 2007


Kevin Bealer wrote:

> Lars Ivar Igesund wrote:
>> Frits van Bommel wrote:
>> 
>>> Which one to use is hard to say at this point. I've been trying out
>>> Tango since its release and I like it but I sometimes miss some parts of
>>> Phobos. Whether this is because Phobos is just more familiar to me or
>>> actually better is hard to say...
>> 
>> Note that what you miss that you feel you have in Phobos, is very much
>> part of the feedback we would like.
>> 
> 
> Okay -- I'm really sorry if any of this seems to have a negative tone.
> I hesitate to write this since I have a lot of respect for the Tango
> design in general, but there are a couple of friction points I've noticed.
> 
> 1. writefln / format replacements
> 
> Concerning standard output and string formatting, in phobos I can do
> these operations:
> 
>    writefln("%s %s %s", a, b, c);
>    format("%s %s %s", a, b, c);
> 
> How do I do these in Tango?  The change to "{0} {1}" stuff is fine with
> me, in fact I like it, but this syntax:
> 
>    Stdout.formatln("{0} {1} {2}", a, b, c);
>    Format!(char).convert("{0} {1} {2}", a, b, c);
> 
> Is awkward.  And these statements are used *all the time*.  In a recent
> toy project I wrote, I used Stdout 15 times, compared to using "foreach"
> only 8 times.  I also use the "format to string" idiom a lot (oddly
> enough, not in that project), and it's even more awkward.
> 
> That's why I think phobos really did the "Right Thing" by keeping those
> down to one token.  Second, the fact that the second one does exactly
> what the first does but you need to build a template, etc, is annoying.
>   I kept asking myself if I was doing the right thing because it seemed
> like I was using too much syntax for this kind of operation (I'm still
> not sure it's the best way to go -- is it?)
> 
> I know about Cout as a replacement for the first one, but as far as I
> can tell it doesn't take parameters, and usually I need some.
> 
> When people ask "why D", I tell them that simpler syntax, better
> defaults and better garbage collection, each gain us a 50 % reduction in
> code, and when all three apply to a problem, D can each C++'s lunch.
> Let's not throw away the simpler syntax.
> 
> (I'm not talking about architecture changes, just wrappers with
> standardized short names that can become familiar to all D users.)
> 
> 
> 2. toString and toUtf8 (collisions)
> 
> The change of the terminology is actually okay with me.
> 
> But phobos has a way of using toString as both a method and a top-level
> function name, all over the place.  This gets really clumsy because you
> can never use the top level function names when writing a class unless
> you fully qualify them.
> 
> For example, std.cpuid.toString(), always has to be fully qualified when
> called from a class, and seems nondescriptive anyway.  All the
> std.conv.toString() functions are nice but it's easy to accidentally
> call the in-class toString() by accident.
> 
> For the utf8 <--> utf16 and similar, it's frustrating to have to do this:
> 
> dchar[] x32 = ...;
> char[] x8 = tango.text.convert.Utf.toUtf8(x32);
> 
> But you have to fully qualify if you are writing code in any class or
> struct.  If these were given another name, like makeUtf8, then these
> collisions would not happen.
> 
> Actually, if it wasn't already out there, I would want to go through all
> of phobos and remove all the common collisions.  They are much less
> trouble in an "import" system than in an "include" system, but every
> time there is a collision it requires an additional "edit-compile"
> cycle, and/or a fully qualified name.
> 
> And if you forget to import all the right modules, its can impact the
> correctness angle, because you pick up someone else's "toString" from
> who knows where.
> 
> I'm just saying, ideally tango should not be duplicating this with
> toUtf8 etc.
> 
> Kevin

I agree with all that is written above but had not had time to write it up
yet. 


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