digitalmars.D.announce - DMD 0.173 release

Walter Bright (4/4) Nov 02 2006 Major new stuff! But please, let's discuss that over in the

Lars Ivar Igesund (6/12) Nov 02 2006 The links in the changelog seems to be dead. (S&S, cpuid)

Mike Parker (3/14) Nov 02 2006 Those particular files are also missing from the documentation in the

Walter Bright (2/7) Nov 02 2006 Fixed.

Don Clugston (5/11) Nov 02 2006

John Reimer (5/14) Nov 07 2006 Yes, it does seem that Walter is heading straight for 2.0. I guess

Lutger (2/8) Nov 02 2006 OMG, template variadics! And standard signal-slots, I'm pretty excited.
Tom (4/10) Nov 02 2006 You seem to be drinking too much caffeine, you're at full speed!
Serg Kovrov (5/7) Nov 02 2006 Yet gain, great work, Walter!
Chris Miller (5/9) Nov 02 2006 Some of my programs get random access violations with this version. Wind...
Pragma (6/12) Nov 02 2006 Holy crap.
John Demme (7/13) Nov 02 2006 The reference links to "A Deeper Look at Signals and Slots" and "Boost

Walter Bright (2/4) Nov 02 2006 Fixed.

Jarrett Billingsley (6/10) Nov 02 2006 Un. Be. Liev. A. Ble.

Jarrett Billingsley (61/65) Nov 02 2006 Waaahaha! This is so cool. A variadic "call" function for MiniD which ...

Chris Nicholson-Sauls (5/86) Nov 02 2006 That has to be about as significant an example as one could ask for. Al...

Bastiaan Veelo (4/10) Nov 02 2006 Excellent! I would love to check out the Signal and Slot implementation....

Brad Anderson (2/3) Nov 02 2006 Resistance is futile.

Chad J (2/8) Nov 02 2006 Variadic templates, and tuples... badass.
Don Clugston (52/56) Nov 03 2006 One of the 'minor things' is also

Walter Bright (3/11) Nov 03 2006 What happens is when one of the parameters is an alias to a local, the

Don Clugston (4/16) Nov 03 2006 OK, that makes sense -- that should prevent the alias from 'leaking out'...
Don Clugston (12/24) Nov 04 2006 I think I've found a bug in a corner case:

Bruno Medeiros (5/11) Nov 05 2006 The file phobos/std_outofmemory.html is still missing from the dmd packa...

Walter Bright (2/3) Nov 06 2006 I'll fix.

Georg Wrede (6/7) Nov 05 2006 Belated congrats!!
Bruno Medeiros (19/19) Nov 05 2006 Ok, so this one is about a feature of some releases ago, but you're

Ivan Senji (10/28) Nov 05 2006 I'm afraid that things have to be that way. It would make sense for

Bill Baxter (14/50) Nov 05 2006 It doesn't even need to be dynamic values. Given

Bill Baxter (21/41) Nov 05 2006 Agreed. It also makes life interesting in that things that depend of an...

Don Clugston (3/9) Nov 06 2006 The relaxed rules for template alias parameters aren't documented in the...

Walter Bright (2/4) Nov 06 2006 I'll fix.

Walter Bright <newshound digitalmars.com> writes:

Major new stuff! But please, let's discuss that over in the 
digitalmars.D group.

http://www.digitalmars.com/d/changelog.html

http://ftp.digitalmars.com/dmd.173.zip

Nov 02 2006

Lars Ivar Igesund <larsivar igesund.net> writes:

Walter Bright wrote:

 Major new stuff! But please, let's discuss that over in the
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

The links in the changelog seems to be dead. (S&S, cpuid)

-- 
Lars Ivar Igesund
blog at http://larsivi.net
DSource & #D: larsivi

Nov 02 2006

Mike Parker <aldacron71 yahoo.com> writes:

Lars Ivar Igesund wrote:
 Walter Bright wrote:
 
 Major new stuff! But please, let's discuss that over in the
 digitalmars.D group.

 http://www.digitalmars.com/d/changelog.html

 http://ftp.digitalmars.com/dmd.173.zip

 
 The links in the changelog seems to be dead. (S&S, cpuid)
 

Those particular files are also missing from the documentation in the 
download.

Nov 02 2006

Walter Bright <newshound digitalmars.com> writes:

Mike Parker wrote:
 Lars Ivar Igesund wrote:
 The links in the changelog seems to be dead. (S&S, cpuid)

 Those particular files are also missing from the documentation in the 
 download.

Fixed.

Nov 02 2006

Don Clugston <dac nospam.com.au> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

<stunned>
Have I slipped through a wormhole? This appears to be an advanced beta 
of DMD 2.0.
</stunned>

Nov 02 2006

"John Reimer" <terminal.node gmail.com> writes:

On Thu, 02 Nov 2006 01:52:42 -0800, Don Clugston <dac nospam.com.au> wrote:

 Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the  
 digitalmars.D group.
  http://www.digitalmars.com/d/changelog.html
  http://ftp.digitalmars.com/dmd.173.zip

 <stunned>
 Have I slipped through a wormhole? This appears to be an advanced beta  
 of DMD 2.0.
 </stunned>


Yes, it does seem that Walter is heading straight for 2.0.  I guess  
there's no stopping the momentum now.  I'm not sure whether this is a good  
idea or not... but whatever... it sure /looks/ impressive.

-JJR

Nov 07 2006

Lutger <lutger.blijdestijn gmail.com> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

OMG, template variadics! And standard signal-slots, I'm pretty excited.

Nov 02 2006

Tom <tom nospam.com> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

You seem to be drinking too much caffeine, you're at full speed!

:)
Tom;

Nov 02 2006

Serg Kovrov <kovrov no.spam> writes:

Hello Walter, you wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.

Yet gain, great work, Walter!
I just want to express my profound respect for you.

-- 
serg.

Nov 02 2006

"Chris Miller" <chris dprogramming.com> writes:

On Thu, 02 Nov 2006 03:53:56 -0500, Walter Bright  
<newshound digitalmars.com> wrote:

 Major new stuff! But please, let's discuss that over in the  
 digitalmars.D group.

 http://www.digitalmars.com/d/changelog.html

 http://ftp.digitalmars.com/dmd.173.zip

Some of my programs get random access violations with this version. Windbg  
says it's somewhere in std.utf's unittest. I rebuilt phobos.lib and the  
problem went away (make -f win32.mak).

Nov 02 2006

Pragma <ericanderton yahoo.removeme.com> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

Holy crap.

So many nice new features.  So little time.

Thank you Walter.

-- 
- EricAnderton at yahoo

Nov 02 2006

John Demme <me teqdruid.com> writes:

Walter Bright wrote:

 Major new stuff! But please, let's discuss that over in the
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

The reference links to "A Deeper Look at Signals and Slots" and "Boost
Signals" appear to be broken.

-- 
~John Demme
me teqdruid.com
http://www.teqdruid.com/

Nov 02 2006

Walter Bright <newshound digitalmars.com> writes:

John Demme wrote:
 The reference links to "A Deeper Look at Signals and Slots" and "Boost
 Signals" appear to be broken.

Fixed.

Nov 02 2006

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"Walter Bright" <newshound digitalmars.com> wrote in message 
news:eicbn3$2qba$1 digitaldaemon.com...
 Major new stuff! But please, let's discuss that over in the digitalmars.D 
 group.

 http://www.digitalmars.com/d/changelog.html

 http://ftp.digitalmars.com/dmd.173.zip

Un.  Be.  Liev.  A.  Ble.

Not only are variadic templates _amazing_ things, they're also _exactly_ 
what I'll need to do the MiniD binding library (and Kirk is understandably 
happy as well!).

Nov 02 2006

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"Jarrett Billingsley" <kb3ctd2 yahoo.com> wrote in message 
news:eidi8o$11o4$2 digitaldaemon.com...
 Un.  Be.  Liev.  A.  Ble.

 Not only are variadic templates _amazing_ things, they're also _exactly_ 
 what I'll need to do the MiniD binding library (and Kirk is understandably 
 happy as well!).

Waaahaha!  This is so cool.  A variadic "call" function for MiniD which used 
to look like:

public void easyCall(MDClosure func, uint numReturns, ...)
 {
  uint funcReg = push(func);

  for(int i = 0; i < _arguments.length; i++)
  {
   TypeInfo ti = _arguments[i];

   if(ti == typeid(bool)) 
push(cast(bool)va_arg!(bool)(_argptr));
   else if(ti == typeid(byte))        push(cast(int)va_arg!(byte)(_argptr));
   else if(ti == typeid(ubyte)) 
push(cast(int)va_arg!(ubyte)(_argptr));
   else if(ti == typeid(short)) 
push(cast(int)va_arg!(ushort)(_argptr));
   else if(ti == typeid(ushort)) 
push(cast(int)va_arg!(ushort)(_argptr));
   else if(ti == typeid(int))         push(cast(int)va_arg!(int)(_argptr));
   else if(ti == typeid(uint))        push(cast(int)va_arg!(uint)(_argptr));
   else if(ti == typeid(long))        push(cast(int)va_arg!(long)(_argptr));
   else if(ti == typeid(ulong)) 
push(cast(int)va_arg!(ulong)(_argptr));
   else if(ti == typeid(float)) 
push(cast(float)va_arg!(float)(_argptr));
   else if(ti == typeid(double)) 
push(cast(float)va_arg!(double)(_argptr));
   else if(ti == typeid(real)) 
push(cast(float)va_arg!(real)(_argptr));
   else if(ti == typeid(char[]))      push(new 
MDString(va_arg!(char[])(_argptr)));
   else if(ti == typeid(wchar[]))     push(new 
MDString(va_arg!(wchar[])(_argptr)));
   else if(ti == typeid(dchar[]))     push(new 
MDString(va_arg!(dchar[])(_argptr)));
   else if(ti == typeid(MDObject)) 
push(cast(MDObject)va_arg!(MDObject)(_argptr));
   else if(ti == typeid(MDUserdata)) 
push(cast(MDUserdata)va_arg!(MDUserdata)(_argptr));
   else if(ti == typeid(MDClosure)) 
push(cast(MDClosure)va_arg!(MDClosure)(_argptr));
   else if(ti == typeid(MDTable)) 
push(cast(MDTable)va_arg!(MDTable)(_argptr));
   else if(ti == typeid(MDArray)) 
push(cast(MDArray)va_arg!(MDArray)(_argptr));
   else throw new MDRuntimeException(this, "MDState.easyCall(): invalid 
parameter ", i);
  }

  call(funcReg, _arguments.length, numReturns);
 }

Has now become:

public void easyCall(T...)(MDClosure func, uint numReturns, T params)
{
 uint funcReg = push(func);

 foreach(param; params)
  push(param);

 call(funcReg, params.length, numReturns);
}

Not only is it magnitudes easier to read, it's also far more efficient.

Amazing, amazing, amazing.  Thank you so much, again and again.

Nov 02 2006

Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:

Jarrett Billingsley wrote:
 "Jarrett Billingsley" <kb3ctd2 yahoo.com> wrote in message 
 news:eidi8o$11o4$2 digitaldaemon.com...
 
Un.  Be.  Liev.  A.  Ble.

Not only are variadic templates _amazing_ things, they're also _exactly_ 
what I'll need to do the MiniD binding library (and Kirk is understandably 
happy as well!).

 
 
 Waaahaha!  This is so cool.  A variadic "call" function for MiniD which used 
 to look like:
 
 public void easyCall(MDClosure func, uint numReturns, ...)
  {
   uint funcReg = push(func);
 
   for(int i = 0; i < _arguments.length; i++)
   {
    TypeInfo ti = _arguments[i];
 
    if(ti == typeid(bool)) 
 push(cast(bool)va_arg!(bool)(_argptr));
    else if(ti == typeid(byte))        push(cast(int)va_arg!(byte)(_argptr));
    else if(ti == typeid(ubyte)) 
 push(cast(int)va_arg!(ubyte)(_argptr));
    else if(ti == typeid(short)) 
 push(cast(int)va_arg!(ushort)(_argptr));
    else if(ti == typeid(ushort)) 
 push(cast(int)va_arg!(ushort)(_argptr));
    else if(ti == typeid(int))         push(cast(int)va_arg!(int)(_argptr));
    else if(ti == typeid(uint))        push(cast(int)va_arg!(uint)(_argptr));
    else if(ti == typeid(long))        push(cast(int)va_arg!(long)(_argptr));
    else if(ti == typeid(ulong)) 
 push(cast(int)va_arg!(ulong)(_argptr));
    else if(ti == typeid(float)) 
 push(cast(float)va_arg!(float)(_argptr));
    else if(ti == typeid(double)) 
 push(cast(float)va_arg!(double)(_argptr));
    else if(ti == typeid(real)) 
 push(cast(float)va_arg!(real)(_argptr));
    else if(ti == typeid(char[]))      push(new 
 MDString(va_arg!(char[])(_argptr)));
    else if(ti == typeid(wchar[]))     push(new 
 MDString(va_arg!(wchar[])(_argptr)));
    else if(ti == typeid(dchar[]))     push(new 
 MDString(va_arg!(dchar[])(_argptr)));
    else if(ti == typeid(MDObject)) 
 push(cast(MDObject)va_arg!(MDObject)(_argptr));
    else if(ti == typeid(MDUserdata)) 
 push(cast(MDUserdata)va_arg!(MDUserdata)(_argptr));
    else if(ti == typeid(MDClosure)) 
 push(cast(MDClosure)va_arg!(MDClosure)(_argptr));
    else if(ti == typeid(MDTable)) 
 push(cast(MDTable)va_arg!(MDTable)(_argptr));
    else if(ti == typeid(MDArray)) 
 push(cast(MDArray)va_arg!(MDArray)(_argptr));
    else throw new MDRuntimeException(this, "MDState.easyCall(): invalid 
 parameter ", i);
   }
 
   call(funcReg, _arguments.length, numReturns);
  }
 
 Has now become:
 
 public void easyCall(T...)(MDClosure func, uint numReturns, T params)
 {
  uint funcReg = push(func);
 
  foreach(param; params)
   push(param);
 
  call(funcReg, params.length, numReturns);
 }
 
 Not only is it magnitudes easier to read, it's also far more efficient.
 
 Amazing, amazing, amazing.  Thank you so much, again and again. 
 
 

That has to be about as significant an example as one could ask for.  Also, the
new code 
makes it much more future-compatable, as it can be made ready for new datatypes
without 
ever editing easyCall itself!  (So long as push() supports the type, you're
good to go.)

-- Chris Nicholson-Sauls

Nov 02 2006

Bastiaan Veelo <Bastiaan Veelo.net> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

Excellent! I would love to check out the Signal and Slot implementation. 
Too bad I am tied up in other projects using other languages.

Bastiaan.

Nov 02 2006

Brad Anderson <brad dsource.org> writes:

Bastiaan Veelo wrote:
 Too bad I am tied up in other projects using other languages.

Resistance is futile.

Nov 02 2006

Chad J <gamerChad _spamIsBad_gmail.com> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

Variadic templates, and tuples... badass.

Nov 02 2006

Don Clugston <dac nospam.com.au> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html

One of the 'minor things' is also

"Template instantiations can now accept alias parameters for local 
variables and nested functions."

which is of great interest to me, since now meta.prettynameof!() can 
work with local variables; this will be significant for DDL and probably 
things like PyD as well.
But, the name mangling is really weird. It's totally different to the 
name mangling for static variables, for example.

Maybe this is intentional, and needs to be that way; but it's a bit 
tricky to parse, so I'd like confirmation that it's not a mistake.

Below is an example, taken from my meta.nameof file.

-----------
     template inner(alias F)
     {
       class inner { }
     }
     template outer(alias B)
     {
       void function( inner!(B) ) outer;
     }
     template rawmanglednameof(alias A)
     {
       const char [] rawmanglednameof  =
                  typeof(&outer!(A)).mangleof;
     }

void wolf() {
        static int proto;
        int quark;

        static assert(rawmanglednameof!(proto)==
        "PPFC"
        ~ "4meta6nameof42__T5inner"
        ~ "S29_D4meta6nameof4wolfFZv"
        ~ "5protoi"
        ~ "Z5innerZv");

         static assert(rawmanglednameof!(quark)==
         "PPFC"

         ~ "_D4meta6nameof4wolfFZv54__T16rawmanglednameof"
         ~ "S29_D4meta6nameof4wolfFZv5quarkiZ42__T5outer"
         ~ "S29_D4meta6nameof4wolfFZv5quarkiZ42__T5inner"

         ~ "S29_D4meta6nameof4wolfFZv"
         ~ "5quarki"
         ~ "Z5innerZv");

/* Why isn't it just:
       "PPFC"
        ~ "4meta6nameof42__T5inner"
        ~ "S29_D4meta6nameof4wolfFZv"
        ~ "5quarki"
        ~ "Z5innerZv"
?
*/
}

Nov 03 2006

Walter Bright <newshound digitalmars.com> writes:

Don Clugston wrote:
 "Template instantiations can now accept alias parameters for local 
 variables and nested functions."
 
 which is of great interest to me, since now meta.prettynameof!() can 
 work with local variables; this will be significant for DDL and probably 
 things like PyD as well.
 But, the name mangling is really weird. It's totally different to the 
 name mangling for static variables, for example.

What happens is when one of the parameters is an alias to a local, the 
template becomes a *nested* class/function, and is mangled like one.

Nov 03 2006

Don Clugston <dac nospam.com.au> writes:

Walter Bright wrote:
 Don Clugston wrote:
 "Template instantiations can now accept alias parameters for local 
 variables and nested functions."

 which is of great interest to me, since now meta.prettynameof!() can 
 work with local variables; this will be significant for DDL and 
 probably things like PyD as well.
 But, the name mangling is really weird. It's totally different to the 
 name mangling for static variables, for example.

 
 What happens is when one of the parameters is an alias to a local, the 
 template becomes a *nested* class/function, and is mangled like one.

OK, that makes sense -- that should prevent the alias from 'leaking out' 
from the function. Might take me a while to get my head around all the 
consequences, though <g>. Opens up lots of possibilities.

Nov 03 2006

Don Clugston <dac nospam.com.au> writes:

Walter Bright wrote:
 Don Clugston wrote:
 "Template instantiations can now accept alias parameters for local 
 variables and nested functions."

 which is of great interest to me, since now meta.prettynameof!() can 
 work with local variables; this will be significant for DDL and 
 probably things like PyD as well.
 But, the name mangling is really weird. It's totally different to the 
 name mangling for static variables, for example.

 
 What happens is when one of the parameters is an alias to a local, the 
 template becomes a *nested* class/function, and is mangled like one.

I think I've found a bug in a corner case:

template t (alias A) {...}

void g() {
   void f() {
//    t!(f);   // CASE 1 --->  template t is nested in both g and f.
  }
    t!(f);    // CASE 2 ---> template t is nested in g but not f.
}

If case 1 appears anywhere (even in a pragma(msg)), it changes the name 
mangling of case 2.
I think case 1 is wrong: an inner function is not inside itself.

Nov 04 2006

Bruno Medeiros <brunodomedeiros+spam com.gmail> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

The file phobos/std_outofmemory.html is still missing from the dmd package.

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D

Nov 05 2006

Walter Bright <newshound digitalmars.com> writes:

Bruno Medeiros wrote:
 The file phobos/std_outofmemory.html is still missing from the dmd package.

I'll fix.

Nov 06 2006

Georg Wrede <georg.wrede nospam.org> writes:

Walter Bright wrote:
 Major new stuff!

Belated congrats!!

At this rate we're well past 2.0 at end of year! :-)

And for anybody contemplating a book on D, don't include the last 
chapter! Reason is, the back cover of the book runs away from you at 
precisely the speed you're writing the next-to-last chapter!  :-)

Nov 05 2006

Bruno Medeiros <brunodomedeiros+spam com.gmail> writes:

Ok, so this one is about a feature of some releases ago, but you're 
releasing new features faster than what we can keep up and look at :P

Regarding array literals, it concerns me that each new literal 
"evaluation" will create a new instance. For example a literal inside a 
function will allocate a new instance every time the function is called. 
Likewise a literal inside a loop will allocate a new instance for every 
cycle of the loop!
This strikes me as both inefficient (as there is no simple way to use 
the opposite behavior: static/global instances) and inconsistent: other 
kinds of literals, like string literals, are not instanced per 
"evaluation" but instead are single/global/static instances.
Is there any particular reason for this behavior? Because if not I'm 
inclined to think it would be better that array literals work as string 
literals (global/static instances). If the new'ed-instance behavior is 
needed it could be easily emulated with dup'ing:
   ar = [1, 4, 9].dup;

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D

Nov 05 2006

Ivan Senji <ivan.senji_REMOVE_ _THIS__gmail.com> writes:

Bruno Medeiros wrote:
 Ok, so this one is about a feature of some releases ago, but you're 
 releasing new features faster than what we can keep up and look at :P

Aint that the truth. :)

 
 Regarding array literals, it concerns me that each new literal 
 "evaluation" will create a new instance. For example a literal inside a 
 function will allocate a new instance every time the function is called. 
 Likewise a literal inside a loop will allocate a new instance for every 
 cycle of the loop!
 This strikes me as both inefficient (as there is no simple way to use 
 the opposite behavior: static/global instances) and inconsistent: other 
 kinds of literals, like string literals, are not instanced per 
 "evaluation" but instead are single/global/static instances.
 Is there any particular reason for this behavior? Because if not I'm 
 inclined to think it would be better that array literals work as string 
 literals (global/static instances). If the new'ed-instance behavior is 
 needed it could be easily emulated with dup'ing:
   ar = [1, 4, 9].dup;
 

I'm afraid that things have to be that way. It would make sense for 
array literals to be allocated only once if they were made of only 
constant values, but in cases like:

for(int i=0; i<100; i++)
{
    f( [i, i*i] );
}

I would expect a new instance to be created at each step in the loop.

Nov 05 2006

Bill Baxter <wbaxter gmail.com> writes:

Ivan Senji wrote:
 Bruno Medeiros wrote:
 
 Ok, so this one is about a feature of some releases ago, but you're 
 releasing new features faster than what we can keep up and look at :P

 
 
 Aint that the truth. :)
 
 Regarding array literals, it concerns me that each new literal 
 "evaluation" will create a new instance. For example a literal inside 
 a function will allocate a new instance every time the function is 
 called. Likewise a literal inside a loop will allocate a new instance 
 for every cycle of the loop!
 This strikes me as both inefficient (as there is no simple way to use 
 the opposite behavior: static/global instances) and inconsistent: 
 other kinds of literals, like string literals, are not instanced per 
 "evaluation" but instead are single/global/static instances.
 Is there any particular reason for this behavior? Because if not I'm 
 inclined to think it would be better that array literals work as 
 string literals (global/static instances). If the new'ed-instance 
 behavior is needed it could be easily emulated with dup'ing:
   ar = [1, 4, 9].dup;

 
 I'm afraid that things have to be that way. It would make sense for 
 array literals to be allocated only once if they were made of only 
 constant values, but in cases like:
 
 for(int i=0; i<100; i++)
 {
    f( [i, i*i] );
 }
 
 I would expect a new instance to be created at each step in the loop.
 

It doesn't even need to be dynamic values.  Given

for(int i=0; i<100; i++)
{
    f( [1, 42] );
}

You might have f modifying the array since D doesn't have good support 
for const:

void f(int[2] v) {
       v[0]++;
}

And then f([1,42]) after the first call becomes equivalent to f([2,42]) 
which would be bad.

--bb

Nov 05 2006

Bill Baxter <wbaxter gmail.com> writes:

Bruno Medeiros wrote:
 Ok, so this one is about a feature of some releases ago, but you're 
 releasing new features faster than what we can keep up and look at :P
 
 Regarding array literals, it concerns me that each new literal 
 "evaluation" will create a new instance. For example a literal inside a 
 function will allocate a new instance every time the function is called. 
 Likewise a literal inside a loop will allocate a new instance for every 
 cycle of the loop!
 This strikes me as both inefficient (as there is no simple way to use 
 the opposite behavior: static/global instances) and inconsistent: other 
 kinds of literals, like string literals, are not instanced per 
 "evaluation" but instead are single/global/static instances.
 Is there any particular reason for this behavior? Because if not I'm 
 inclined to think it would be better that array literals work as string 
 literals (global/static instances). If the new'ed-instance behavior is 
 needed it could be easily emulated with dup'ing:
   ar = [1, 4, 9].dup;
 

Agreed.  It also makes life interesting in that things that depend of an 
array having compile-time constant value fail:

   const bool[3] a = [true,false,true];
   static if(a[0]) {}

(and fail with the misleading error message "expression (a)[0] does not 
evaluate to a boolean").

This is ok though:
   static if([true,false,true][0]) {}

Another thing that should work is:

    static const int[3] a = [4,5,6];
    static const int[a[0]] b = [1,2,3,4];

test.d(17): a is used as a type
test.d(17): can't have associative array key of void[0]

Ok, that's maybe a different issue... but I bet if it weren't trying to 
interpret the above as an associative array it would be complaining that 
the value a[0] isn't constant.  :-)

Ah, here's a better example:

   static const int[2] sizes = [2,4];
   static const int[2] use_sizes = [sizes[0], sizes[1]];

 staticdata.d(19): non-constant expression (sizes)[0]
 staticdata.d(19): non-constant expression (sizes)[1]


--bb

Nov 05 2006

Don Clugston <dac nospam.com.au> writes:

Walter Bright wrote:
 Major new stuff! But please, let's discuss that over in the 
 digitalmars.D group.
 
 http://www.digitalmars.com/d/changelog.html
 
 http://ftp.digitalmars.com/dmd.173.zip

The relaxed rules for template alias parameters aren't documented in the 
spec. The example under 'global names' compiles now <g>.

Nov 06 2006

Walter Bright <newshound digitalmars.com> writes:

Don Clugston wrote:
 The relaxed rules for template alias parameters aren't documented in the 
 spec. The example under 'global names' compiles now <g>.

I'll fix.

Nov 06 2006

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