digitalmars.D - UCFS, Reflection/Metadata, Overload Resolution, Templates, and other issues

%u (15/15) Apr 07 2011 I was trying to write a "Dynamic" class for D, which uses opDispatch

Steven Schveighoffer (10/25) Apr 07 2011 I tried a "wrapper" type using opDispatch in dcollections, but what I ra...

%u (118/119) Apr 07 2011 I ran into is, opDispatch uses its called parameter types to decide

Caligo (1/1) Apr 07 2011 What's UCFS?

%u (1/2) Apr 07 2011 Whoops, typo. xD Uniform Function Call Syntax. :)

Robert Jacques (11/26) Apr 07 2011 I've added reflection capabilities to an update to std.variant I'm worki...

%u (6/8) Apr 08 2011 General functions work. (Although a few bugs with opCall and opDispatch ...

Robert Jacques (6/20) Apr 08 2011 Here's a snapshot I posted a while ago, if you'd like to have a look:

%u (18/18) Apr 09 2011 Thanks for the link!

Robert Jacques (9/30) Apr 09 2011 Sorry. It was late and I forgot to mention some things. A) My code is

%u (10/11) Apr 09 2011 changes, etc, that I had to make to go from DMD 2.051 to DMD 2.052. I've...

Robert Jacques (6/24) Apr 10 2011 Well, 5155 is fairly simple. The bug report details four one line change...

%u (8/9) Apr 12 2011 changes to Object.di and Object_.d. See

%u <wfunction hotmail.com> writes:

I was trying to write a "Dynamic" class for D, which uses opDispatch
to allow for late binding, but I ran into a problem:

While my class works well for regular methods inside a class, it
fails to work for:
(1) Template methods inside a class
(2) Methods with overloads
(3) Global methods that have nothing to do with a class, like
writeln
Furthermore, it would also fail to work for (4) UCFS if/when it's
implemented.

It seems like templates by design *don't* allow for anything to
happen dynamically, and at the same time, it seems like _everything_
is becoming a template nowadays.

So my question is, is there anything we can do about it (either now
or later)? Or is a dynamic extension simply beyond the reach of D?

Apr 07 2011

"Steven Schveighoffer" <schveiguy yahoo.com> writes:

On Thu, 07 Apr 2011 14:20:53 -0400, %u <wfunction hotmail.com> wrote:

 I was trying to write a "Dynamic" class for D, which uses opDispatch
 to allow for late binding, but I ran into a problem:

 While my class works well for regular methods inside a class, it
 fails to work for:
 (1) Template methods inside a class
 (2) Methods with overloads
 (3) Global methods that have nothing to do with a class, like
 writeln
 Furthermore, it would also fail to work for (4) UCFS if/when it's
 implemented.

 It seems like templates by design *don't* allow for anything to
 happen dynamically, and at the same time, it seems like _everything_
 is becoming a template nowadays.

 So my question is, is there anything we can do about it (either now
 or later)? Or is a dynamic extension simply beyond the reach of D?

I tried a "wrapper" type using opDispatch in dcollections, but what I ran  
into is, opDispatch uses its called parameter types to decide the function  
parameter types, you have very little control over that.  I basically  
ended up abandoning the use of opDispatch and implemented each covered  
function by hand.

I filed an enhancement request for it, which probably doesn't cover  
everything you listed, but it might help:

http://d.puremagic.com/issues/show_bug.cgi?id=4998

-Steve

Apr 07 2011

%u <wfunction hotmail.com> writes:

 I tried a "wrapper" type using opDispatch in dcollections, but what

I ran into is, opDispatch uses its called parameter types to decide
the function parameter types, you have very little control over that.
I basically ended up abandoning the use of opDispatch and implemented
each covered function by hand.

I managed to get this far (my file attached), using D-style runtime
variadic functions... it seems to work well in most cases, with the
notable exceptions being:
(1) Things I already mentioned
(2) Possibly ref/out/lazy parameters (I haven't tested them yet)

Any thoughts?
begin 644 std.dynamic.core.d

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end

Apr 07 2011

Caligo <iteronvexor gmail.com> writes:

What's UCFS?

Apr 07 2011

%u <wfunction hotmail.com> writes:

 What's UCFS?

Whoops, typo. xD Uniform Function Call Syntax. :)

Apr 07 2011

"Robert Jacques" <sandford jhu.edu> writes:

On Thu, 07 Apr 2011 14:20:53 -0400, %u <wfunction hotmail.com> wrote:

 I was trying to write a "Dynamic" class for D, which uses opDispatch
 to allow for late binding, but I ran into a problem:

 While my class works well for regular methods inside a class, it
 fails to work for:
 (1) Template methods inside a class
 (2) Methods with overloads
 (3) Global methods that have nothing to do with a class, like
 writeln
 Furthermore, it would also fail to work for (4) UCFS if/when it's
 implemented.

 It seems like templates by design *don't* allow for anything to
 happen dynamically, and at the same time, it seems like _everything_
 is becoming a template nowadays.

 So my question is, is there anything we can do about it (either now
 or later)? Or is a dynamic extension simply beyond the reach of D?

I've added reflection capabilities to an update to std.variant I'm working  
on. Overloads work. General functions work. (Although a few bugs with  
opCall and opDispatch prevents the ideal syntax: var.x(5) vs var.x = 5 and  
var.call(5) vs var(5), but I assume those will be eventually fixed). I've  
also added an internal type database, so you can auto-magically build a  
Variant(TypeInfo, void*) or Variant(Object) and then call methods on the  
real, underlying type.

Templates, I think, will out of the range of dynamic D capabilities for  
some time to come.

Also, because I'm wrapping / unwrapping all arguments, ref doesn't work.

Apr 07 2011

%u <wfunction hotmail.com> writes:

 I've added reflection capabilities to an update to std.variant I'm working on.
Overloads work.

General functions work. (Although a few bugs with opCall and opDispatch
prevents the ideal syntax:
var.x(5) vs var.x = 5 and var.call(5) vs var(5), but I assume those will be
eventually fixed). I've
also added an internal type database, so you can auto-magically build a
Variant(TypeInfo, void*) or
Variant(Object) and then call methods on the real, underlying type.

Whoa nice. I'm eagerly waiting to see it. :)


 Templates, I think, will out of the range of dynamic D capabilities for some
time to come.

Yeah, 'cause I just realized they basically need you to implement the entire
compiler.

Apr 08 2011

"Robert Jacques" <sandford jhu.edu> writes:

On Fri, 08 Apr 2011 11:31:48 -0400, %u <wfunction hotmail.com> wrote:

 I've added reflection capabilities to an update to std.variant I'm  
 working on. Overloads work.

 General functions work. (Although a few bugs with opCall and opDispatch  
 prevents the ideal syntax:
 var.x(5) vs var.x = 5 and var.call(5) vs var(5), but I assume those will  
 be eventually fixed). I've
 also added an internal type database, so you can auto-magically build a  
 Variant(TypeInfo, void*) or
 Variant(Object) and then call methods on the real, underlying type.

 Whoa nice. I'm eagerly waiting to see it. :)

Here's a snapshot I posted a while ago, if you'd like to have a look:
https://jshare.johnshopkins.edu/rjacque2/public_html/

I'd love some feedback, particularly with regard to the runtime-reflection  
API.

 Templates, I think, will out of the range of dynamic D capabilities for  
 some time to come.

 Yeah, 'cause I just realized they basically need you to implement the  
 entire compiler.

Yah, you'd need a VM.

Apr 08 2011

%u <wfunction hotmail.com> writes:

Thanks for the link!

I tried compiling the file, and I got these errors:

variant.d(454): Warning: statement is not reachable
variant.d(454): Warning: statement is not reachable
variant.d(454): Warning: statement is not reachable
variant.d(634): Warning: statement is not reachable
variant.d(660): Warning: statement is not reachable
variant.d(337): Error: template variant.Variant.Box.opAssign(A : Variant) does
not match any function template declaration
variant.d(337): Error: template variant.Variant.Box.opAssign(A : Variant)
cannot deduce template function from argument types !
()(char[])
variant.d(612): Error: template instance variant.Variant.Box.opAssign!(char[])
error instantiating
variant.d(1041): instantiated from here: __vtableOf!(char[])
variant.d(605): instantiated from here: opAssign!(char[])
variant.d(757): instantiated from here: SaveResult!(char[])
    ... (23 instantiations, -v to show) ...
variant.d(376): instantiated from here: SaveResult!(TypeInfo)
variant.d(351): instantiated from here: __vtableOf!(void)

Any ideas how I should fix them?

Apr 09 2011

"Robert Jacques" <sandford jhu.edu> writes:

On Sat, 09 Apr 2011 04:07:11 -0400, %u <wfunction hotmail.com> wrote:

 Thanks for the link!

 I tried compiling the file, and I got these errors:

 variant.d(454): Warning: statement is not reachable
 variant.d(454): Warning: statement is not reachable
 variant.d(454): Warning: statement is not reachable
 variant.d(634): Warning: statement is not reachable
 variant.d(660): Warning: statement is not reachable
 variant.d(337): Error: template variant.Variant.Box.opAssign(A :  
 Variant) does not match any function template declaration
 variant.d(337): Error: template variant.Variant.Box.opAssign(A :  
 Variant) cannot deduce template function from argument types !
 ()(char[])
 variant.d(612): Error: template instance  
 variant.Variant.Box.opAssign!(char[]) error instantiating
 variant.d(1041): instantiated from here: __vtableOf!(char[])
 variant.d(605): instantiated from here: opAssign!(char[])
 variant.d(757): instantiated from here: SaveResult!(char[])
     ... (23 instantiations, -v to show) ...
 variant.d(376): instantiated from here: SaveResult!(TypeInfo)
 variant.d(351): instantiated from here: __vtableOf!(void)

 Any ideas how I should fix them?

Sorry. It was late and I forgot to mention some things. A) My code is  
dependent on patch 5155, and B) I forgot about changes, etc, that I had to  
make to go from DMD 2.051 to DMD 2.052. I've uploaded my current working  
copy and remade the docs. Let me know if you have any issues with this.  
(And please include a brief description of what/how you're building it:  
i.e. dmd 2.052, debug mode, etc) Also, if you want to try my updated  
std.json, it requires a few more patches, each listed at the top of the  
file.

Apr 09 2011

%u <wfunction hotmail.com> writes:

 Sorry. It was late and I forgot to mention some things. A) My code is
dependent on patch 5155, and B) I forgot about

changes, etc, that I had to make to go from DMD 2.051 to DMD 2.052. I've
uploaded my current working copy and remade the
docs. Let me know if you have any issues with this. (And please include a brief
description of what/how you're building
it: i.e. dmd 2.052, debug mode, etc) Also, if you want to try my updated
std.json, it requires a few more patches, each
listed at the top of the file.



Whoops my bad. I'm using DMD 2.052, the version on the website, to compile
variant.d. I tried recompiling the file
(standalone) and got the same error again; I suspect it's because of the patch
5155 you mentioned, which I haven't
applied.
I'm actually not familiar with the patching system yet, so I'll try to use your
file when I find a bit more time to
figure it out.

Thanks! :)

Apr 09 2011

"Robert Jacques" <sandford jhu.edu> writes:

On Sat, 09 Apr 2011 18:08:58 -0400, %u <wfunction hotmail.com> wrote:

 Sorry. It was late and I forgot to mention some things. A) My code is  
 dependent on patch 5155, and B) I forgot about

 changes, etc, that I had to make to go from DMD 2.051 to DMD 2.052. I've  
 uploaded my current working copy and remade the
 docs. Let me know if you have any issues with this. (And please include  
 a brief description of what/how you're building
 it: i.e. dmd 2.052, debug mode, etc) Also, if you want to try my updated  
 std.json, it requires a few more patches, each
 listed at the top of the file.



 Whoops my bad. I'm using DMD 2.052, the version on the website, to  
 compile variant.d. I tried recompiling the file
 (standalone) and got the same error again; I suspect it's because of the  
 patch 5155 you mentioned, which I haven't
 applied.
 I'm actually not familiar with the patching system yet, so I'll try to  
 use your file when I find a bit more time to
 figure it out.

 Thanks! :)

Well, 5155 is fairly simple. The bug report details four one line changes  
to Object.di and Object_.d. See  
http://d.puremagic.com/issues/show_bug.cgi?id=5155
Also, If that doesn't do the trick, please e-mail me as I would like to  
fix the root cause. (And let you test the library)

Apr 10 2011

%u <wfunction hotmail.com> writes:

 Well, 5155 is fairly simple. The bug report details four one line

changes to Object.di and Object_.d. See
http://d.puremagic.com/issues/show_bug.cgi?id=5155
Also, If that doesn't do the trick, please e-mail me as I would like
to fix the root cause. (And let you test the library)

Oops sorry, I got a bit busier these couple of days and totally forgot
about this. I'll try to come back to it in the near future, and I'll
let you know if I have any success/failure.

Thanks for the info! :)

Apr 12 2011

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digitalmars.D - UCFS, Reflection/Metadata, Overload Resolution, Templates, and other issues