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digitalmars.D.announce - Boost::Any ported to D

reply Marcin Kuszczak <aarti interia.pl> writes:
Hello all!

I am happy to announce that Boost::any is now ported to D Programming
Language. 

You can find sources in attachment. You can find there also original boost
file for reference.

Documentation is on boost site: http://boost.org/doc/html/any.html - with
below modifications:
1. You can not construct Any type with specific value as parameter of
constructor.
2. There is no assignment operator in D, so I used function template
function assign()

Test program attached.

After translation I have to say that D is great - source is about half size
of original and is much more understantable (I hope) <g>.

I encountered also few problems when porting from C++. Some of them are
probably bugs, some, maybe are D Language design decisions - I would be
happy to know how to threat them.

Here are they:
1. I couldn't make templatized class constructor
        this(ValueType)(ValueType v);
   It seems that it shouldn't be a problem to support such a construct in 
   language - constructor is very similar to method which can be 
   templatized.
2. Arrays with static size are not fully supported e.g. function can not
return static array. Also static arrays are not implicitly converted to
dynamic arrays, so when assigning string to Any class there is a need to
cast to dynamic array:
        (new Any).assign(cast(char[])("char[] test"));
3. I can not compile program after putting PlaceHolder interface and Holder
class into Any class (like in the original approach). Is it bug or am I
doing something wrong?
4. Why specialization for implicitly instatiated function templates is not
possible? (But it is possible to use static if and is operator).
5. It seems that compiler works different when calling it in different way -
at least on Linux.
For example below commands are not equivalent:
dmd test_any.d any.d
above command works

dmd -c -I../../ test_any.d
dmd -c any.d
gcc test_any.o any.o -o test_any -m32 -lphobos -lpthread -lm -Xlinker -ldl
above command produces error message:
test_any.o: In function
`_D5doost3any3any28__T7anyCastTC8test_any4TestZ7anyCastFC5doost3any3any3AnyZC8test_any4Test':test_any.d
(.gnu.linkonce.t_D5doost3any3any28__T7anyCastTC8test_any4TestZ7anyCastFC5doost3any3any3AnyZC8test_any4Test+0x54):
undefined reference to `_init_24TypeInfo_C8test_any4Test'
test_any.o: In function
`_D5doost3any3any27__T6HolderTC8test_any4TestZ6Holder4typeFZC8TypeInfo':test_any.d
(.gnu.linkonce.t_D5doost3any3any27__T6HolderTC8test_any4TestZ6Holder4typeFZC8TypeInfo+0x9):
undefined reference to `_init_24TypeInfo_C8test_any4Test'
collect2: ld returned 1 exit status

It seems that similar situation is when using Box from std.boxer. It is
especially painful as very good IDE Codeblocks uses this method of
compilation of D programs.

I used namespace doost (read: dust :-)) as I think it would be good idea to
put all classes translated from boost to one library. (I am also in
progress of translating boost::program_options, which will also be putted
into doost namespace).

Review of code and comments are welcomed.

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Sep 24 2006
next sibling parent reply Lionello Lunesu <lio lunesu.remove.com> writes:
Just for my understanding: is this like std.boxer?

L.
Sep 25 2006
parent Aarti_pl <aarti interia.pl> writes:
Lionello Lunesu napisał(a):

 Just for my understanding: is this like std.boxer?
 
 L.


Yes. But without problems of std.boxer :-)

Problems with std.boxer:

1. I couldn't get information from Box type if Box is empty. There is no 
direct access to data[] property. The only way I could find is invoke on 
Box .toString method and check if returned value is "<empty string>" . 
As you see it's rather obscure.

2. I think that Any implementation is much cleaner. In std.boxer 
implementation box function gets as argument variadic number of 
parameters. Assertion is make if there is more than one parameter 
passed. And arguments type is checked on runtime...

3. Implementation of boxer seems to be much longer. boxer.d is about 29 
Kb, when any.d is just 2Kb (but without unit tests and comments - it 
will be added later)

In other hand I did not test Any with pointer types and other more 
exotic types - i will do it as i will have a little bit of free time :-)

Regards
Marcin Kuszczak
Sep 25 2006
prev sibling parent reply Bruno Medeiros <brunodomedeiros+spam com.gmail> writes:
Marcin Kuszczak wrote:

 
 I encountered also few problems when porting from C++. Some of them are
 probably bugs, some, maybe are D Language design decisions - I would be
 happy to know how to threat them.
 
 Here are they:
 1. I couldn't make templatized class constructor
         this(ValueType)(ValueType v);
    It seems that it shouldn't be a problem to support such a construct in 
    language - constructor is very similar to method which can be 
    templatized.


Indeed.


 2. Arrays with static size are not fully supported e.g. function can not
 return static array. Also static arrays are not implicitly converted to
 dynamic arrays, so when assigning string to Any class there is a need to
 cast to dynamic array:
         (new Any).assign(cast(char[])("char[] test"));


Static arrays are teh suck. :(
"Certain aspects of D are a pathway to many issues some consider to 
be... unnatural." :P


 3. I can not compile program after putting PlaceHolder interface and Holder
 class into Any class (like in the original approach). Is it bug or am I
 doing something wrong?


Hum, C++ allows member(=inner) classes? Didn't know that. Are they 
static or "instance"(meaning they require an outer class context) classes?
Recall that in D they are "instance" by default, and static on option only.


 4. Why specialization for implicitly instatiated function templates is not
 possible? (But it is possible to use static if and is operator).


What exactly did you want to do? Is it like the issue here: 
http://d.puremagic.com/issues/show_bug.cgi?id=337 ? Are the workarounds 
there acceptable?

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D
Sep 26 2006
next sibling parent reply Marcin Kuszczak <aarti interia.pl> writes:
Bruno Medeiros wrote:


 Marcin Kuszczak wrote:

 3. I can not compile program after putting PlaceHolder interface and
 Holder class into Any class (like in the original approach). Is it bug or
 am I doing something wrong?


 
 Hum, C++ allows member(=inner) classes? Didn't know that. Are they
 static or "instance"(meaning they require an outer class context) classes?
 Recall that in D they are "instance" by default, and static on option
 only.


As I know outer class works just as namespace for inner class. So I would
say static class definitions.


 

 4. Why specialization for implicitly instatiated function templates is
 not possible? (But it is possible to use static if and is operator).


 
 What exactly did you want to do? Is it like the issue here:
 http://d.puremagic.com/issues/show_bug.cgi?id=337 ? Are the workarounds
 there acceptable?
 


I used workaround with static if:

Any assign(ValueType)(ValueType value) {
        static if (is(ValueType == Any)) content = value.content!=null ? 
                value.content.clone() : null;
        else content=new Holder!(ValueType)(value);
        return this;
}

but why below doesn't work?:
Any assign(ValueType)(ValueType value) {
        content=new Holder!(ValueType)(value);
        return this;
}

Any assign(ValueType : Any)(ValueType value) {
        content = value.content!=null ? value.content.clone() : null;
        return this;
}

according to documentation specialization is not permitted when using
implicit instatiation. But still don't know why...

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Sep 26 2006
next sibling parent reply notknown <notknown none.com> writes:
I was just wondering if this is still the case with D, but iirc at least 
some time ago I remember that you should use "is" keyword to test if 
object is null because "==" means opEquals.



 I used workaround with static if:
 
 Any assign(ValueType)(ValueType value) {
         static if (is(ValueType == Any)) content = value.content!=null ? 
                 value.content.clone() : null;
         else content=new Holder!(ValueType)(value);
         return this;
 }
 
 but why below doesn't work?:
 Any assign(ValueType)(ValueType value) {
         content=new Holder!(ValueType)(value);
         return this;
 }
 
 Any assign(ValueType : Any)(ValueType value) {
         content = value.content!=null ? value.content.clone() : null;
         return this;
 }
 
 according to documentation specialization is not permitted when using
 implicit instatiation. But still don't know why...
 


static if (is(ValueType == Any)) content = value.content !is null ?
         value.content.clone() : null;                     ^----- there


Or then I have old/wrong information.
Sep 27 2006
parent Marcin Kuszczak <aarti interia.pl> writes:
notknown wrote:


  wondering if this is still the case with D, but iirc at least
 some time ago I remember that you should use "is" keyword to test if
 object is null because "==" means opEquals.


Probably you are right :-) Thanks for remark.

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Sep 27 2006
prev sibling parent reply Bruno Medeiros <brunodomedeiros+spam com.gmail> writes:
Marcin Kuszczak wrote:

 Bruno Medeiros wrote:
 

 Marcin Kuszczak wrote:

 3. I can not compile program after putting PlaceHolder interface and
 Holder class into Any class (like in the original approach). Is it bug or
 am I doing something wrong?


 Hum, C++ allows member(=inner) classes? Didn't know that. Are they
 static or "instance"(meaning they require an outer class context) classes?
 Recall that in D they are "instance" by default, and static on option
 only.


 
 As I know outer class works just as namespace for inner class. So I would
 say static class definitions.
 


And when you ported to D, did you make the D inner classes static too?

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D
Oct 02 2006
parent Marcin Kuszczak <aarti interia.pl> writes:
Bruno Medeiros wrote:


 Marcin Kuszczak wrote:

 Bruno Medeiros wrote:
 

 Marcin Kuszczak wrote:

 3. I can not compile program after putting PlaceHolder interface and
 Holder class into Any class (like in the original approach). Is it bug
 or am I doing something wrong?


 Hum, C++ allows member(=inner) classes? Didn't know that. Are they
 static or "instance"(meaning they require an outer class context)
 classes? Recall that in D they are "instance" by default, and static on
 option only.


 
 As I know outer class works just as namespace for inner class. So I would
 say static class definitions.
 


 
 And when you ported to D, did you make the D inner classes static too?
 


After some more experiments it occurs that I can move Holder class into Any
class without problems. It could be putted into public or private section.
It doesn't have to have keyword static to work well.

Problems are beginning when I move interface PlaceHolder into private
section of Any. After that I get linking errors:

dmd test_any.d any.d
gcc test_any.o any.o -o test_any -m32 -lphobos -lpthread -lm -Xlinker -ldl
test_any.o: In function
`_D5doost3any3any3Any31__T6assignTC5doost3any3any3AnyZ6assignFC5doost3any3any3AnyZC5doost3any3any3Any':test_any.d
(.gnu.linkonce.t_D5doost3any3any3Any31__T6assignTC5doost3any3any3AnyZ6assignFC5doost3any3any3AnyZC5doost3any3any3Any+0x1b):
undefined reference to
`_D5doost3any3any3Any11PlaceHolder5cloneFZC5doost3any3any3Any11PlaceHolder'
any.o: In function `_D5doost3any3any3Any4typeFZC8TypeInfo':any.d
(.gnu.linkonce.t_D5doost3any3any3Any4typeFZC8TypeInfo+0x1b): undefined
reference to `_D5doost3any3any3Any11PlaceHolder4typeFZC8TypeInfo'
collect2: ld returned 1 exit status
--- errorlevel 1


What is more interesting there is no problem when I put interface into
public section of Any.

In attachment best code which works.

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Oct 02 2006
prev sibling parent reply Fredrik Olsson <peylow gmail.com> writes:
Bruno Medeiros skrev:

 2. Arrays with static size are not fully supported e.g. function can not
 return static array. Also static arrays are not implicitly converted to
 dynamic arrays, so when assigning string to Any class there is a need to
 cast to dynamic array:
         (new Any).assign(cast(char[])("char[] test"));


 
 Static arrays are teh suck. :(
 "Certain aspects of D are a pathway to many issues some consider to 
 be... unnatural." :P
 


Perhaps a prefix is in order, in your example:
(new Any).assign(d"char[] test"); // Dynamic
(new Any).assign(s"char[] test"); // Static

And same for the new array literals (That I love).
(new Any).assign(d[1,2,3]); // Dynamic
(new Any).assign(s[1,2,3]); // Static

I guess no prefix would default to static as is?


(And before you even think about going about to complain about choosing 
'd', and 's' as prefixes have in mind: I do not care if any other 
character is used, if it is postfix instead, or whatere. It is the 
functionality I want!)


// Fredrik Olsson
Sep 26 2006
next sibling parent reply Oskar Linde <oskar.lindeREM OVEgmail.com> writes:
Fredrik Olsson wrote:

 Perhaps a prefix is in order, in your example:
 (new Any).assign(d"char[] test"); // Dynamic
 (new Any).assign(s"char[] test"); // Static
 
 And same for the new array literals (That I love).
 (new Any).assign(d[1,2,3]); // Dynamic
 (new Any).assign(s[1,2,3]); // Static
 
 I guess no prefix would default to static as is?
 
 
 (And before you even think about going about to complain about choosing 
 'd', and 's' as prefixes have in mind: I do not care if any other 
 character is used, if it is postfix instead, or whatere. It is the 
 functionality I want!)


There is already a postfix: []

"test"[] // Dynamic
"test" // Static

/Oskar
Sep 26 2006
next sibling parent reply Fredrik Olsson <peylow gmail.com> writes:
Oskar Linde skrev:

 Fredrik Olsson wrote:

 Perhaps a prefix is in order, in your example:




<snip>

 There is already a postfix: []
 
 "test"[] // Dynamic
 "test" // Static
 


Ah, stupid of me. I like it.

But where is this documented? I can not find any mention about it under 
StringLiterals, and ArrayLiterals under expressions.


// Fredrik
Sep 27 2006
parent reply Oskar Linde <oskar.lindeREM OVEgmail.com> writes:
Fredrik Olsson wrote:

 Oskar Linde skrev:

 Fredrik Olsson wrote:

 Perhaps a prefix is in order, in your example:




 <snip>

 There is already a postfix: []

 "test"[] // Dynamic
 "test" // Static


 
 Ah, stupid of me. I like it.
 
 But where is this documented? I can not find any mention about it under 
 StringLiterals, and ArrayLiterals under expressions.


Not very well documented, but:

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

"""
SliceExpression:
	PostfixExpression [ ]
	PostfixExpression [ AssignExpression .. AssignExpression ]
"""

The first form is the full slice. It seems to be missing from

http://www.digitalmars.com/d/expression.html#SliceExpression

though.

/Oskar
Sep 27 2006
parent Fredrik Olsson <peylow gmail.com> writes:
Oskar Linde skrev:

 Fredrik Olsson wrote:

 Oskar Linde skrev:

 Fredrik Olsson wrote:

 Perhaps a prefix is in order, in your example:




 <snip>

 There is already a postfix: []

 "test"[] // Dynamic
 "test" // Static


 Ah, stupid of me. I like it.

 But where is this documented? I can not find any mention about it 
 under StringLiterals, and ArrayLiterals under expressions.


 
 Not very well documented, but:
 
 http://www.digitalmars.com/d/expression.html
 
 """
 SliceExpression:
     PostfixExpression [ ]
     PostfixExpression [ AssignExpression .. AssignExpression ]
 """
 
 The first form is the full slice. It seems to be missing from
 
 http://www.digitalmars.com/d/expression.html#SliceExpression
 
 though.
 


Aah, I see. Not as much an intentional postfix, as an useful side-effect 
of slicing. Goot thing(tm), a small amount of highly flexible stuff, is 
way better then tons of specialization.

// Fredrik Olsson


 /Oskar
Sep 27 2006
prev sibling parent Marcin Kuszczak <aarti interia.pl> writes:
Oskar Linde wrote:


 Fredrik Olsson wrote:

 Perhaps a prefix is in order, in your example:
 (new Any).assign(d"char[] test"); // Dynamic
 (new Any).assign(s"char[] test"); // Static
 
 And same for the new array literals (That I love).
 (new Any).assign(d[1,2,3]); // Dynamic
 (new Any).assign(s[1,2,3]); // Static
 
 I guess no prefix would default to static as is?
 
 
 (And before you even think about going about to complain about choosing
 'd', and 's' as prefixes have in mind: I do not care if any other
 character is used, if it is postfix instead, or whatere. It is the
 functionality I want!)


 
 There is already a postfix: []
 
 "test"[] // Dynamic
 "test" // Static
 
 /Oskar


Postfix form works well, opposite to prefix form which doesn't...

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Sep 27 2006
prev sibling parent reply Marcin Kuszczak <aarti interia.pl> writes:
Fredrik Olsson wrote:


 Bruno Medeiros skrev:

 2. Arrays with static size are not fully supported e.g. function can not
 return static array. Also static arrays are not implicitly converted to
 dynamic arrays, so when assigning string to Any class there is a need to
 cast to dynamic array:
         (new Any).assign(cast(char[])("char[] test"));


 
 Static arrays are teh suck. :(
 "Certain aspects of D are a pathway to many issues some consider to
 be... unnatural." :P
 


 Perhaps a prefix is in order, in your example:
 (new Any).assign(d"char[] test"); // Dynamic
 (new Any).assign(s"char[] test"); // Static
 
 And same for the new array literals (That I love).
 (new Any).assign(d[1,2,3]); // Dynamic
 (new Any).assign(s[1,2,3]); // Static
 
 I guess no prefix would default to static as is?
 
 
 (And before you even think about going about to complain about choosing
 'd', and 's' as prefixes have in mind: I do not care if any other
 character is used, if it is postfix instead, or whatere. It is the
 functionality I want!)
 
 
 // Fredrik Olsson


Unfortunately this functionality doesn't work with my installed compiler
(dmd 0.167 / Linux) :-( I assume it is a bug?

None of your examples work (I get "undefined identifier d" error)
(new Any).assign(d"char[] test"); // Dynamic
(new Any).assign(s"char[] test"); // Static
(new Any).assign(d[1,2,3]); // Dynamic
(new Any).assign(s[1,2,3]); // Static

Does it work on Windows?

-- 
Regards
Marcin Kuszczak
(Aarti_pl)
Sep 27 2006
parent Fredrik Olsson <peylow gmail.com> writes:
Marcin Kuszczak skrev:

 Fredrik Olsson wrote:


<snip>

 // Fredrik Olsson


 
 Unfortunately this functionality doesn't work with my installed compiler
 (dmd 0.167 / Linux) :-( I assume it is a bug?
 
 None of your examples work (I get "undefined identifier d" error)
 (new Any).assign(d"char[] test"); // Dynamic
 (new Any).assign(s"char[] test"); // Static
 (new Any).assign(d[1,2,3]); // Dynamic
 (new Any).assign(s[1,2,3]); // Static
 
 Does it work on Windows?
 


I seriously doubt it :). This was just a suggestion for how it could be 
done.

Oskar Linde has since then teached me that this would be the correct and 
working way:
(new Any).assign("char[] test"[]); // Dynamic
(new Any).assign("char[] test"); // Static
(new Any).assign([1,2,3][]); // Dynamic
(new Any).assign([1,2,3]); // Static


// Fredrik Olsson
Sep 27 2006