www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Loop through all modules and module members?

reply %u <wfunction hotmail.com> writes:
Hi,

I would like to perform compile-time reflection on a module (such as
enumerating all the classes inside the module) and/or on all modules in the
code -- are either of these possible? And if so, how?

Thank you!
Dec 31 2010
parent reply bearophile <bearophileHUGS lycos.com> writes:
%u:


 I would like to perform compile-time reflection on a module (such as
 enumerating all the classes inside the module) and/or on all modules in the
 code -- are either of these possible? And if so, how?


You may add your enhancement requests here, explaining why you need them:
http://d.puremagic.com/issues/show_bug.cgi?id=4476

At the moment the static reflection is not able to do everything. Listing all
modules in the code looks like work for rmdm. Listing all classes in a module
seems work for __traits/meta, plus a compile-time Filter.

Bye,
bearophile
Jan 01 2011
next sibling parent Philippe Sigaud <philippe.sigaud gmail.com> writes:
On Sat, Jan 1, 2011 at 11:14, bearophile <bearophileHUGS lycos.com> wrote:

 %u:


 I would like to perform compile-time reflection on a module (such as
 enumerating all the classes inside the module) and/or on all modules in the
 code -- are either of these possible? And if so, how?


 You may add your enhancement requests here, explaining why you need them:
 http://d.puremagic.com/issues/show_bug.cgi?id=4476

 At the moment the static reflection is not able to do everything. Listing all
modules in the code looks like work for rmdm. Listing all classes in a module
seems work for __traits/meta, plus a compile-time Filter.


Yes, it's doable :

template StaticFilter(alias Pred, T...)
{
    static if (T.length == 0)
        alias TypeTuple!() StaticFilter;
    else static if (Pred!(T[0]))
        alias TypeTuple!(T[0], StaticFilter!(Pred, T[1 .. $])) StaticFilter;
    else
        alias StaticFilter!(Pred, T[1 .. $]) StaticFilter;
}

template isClass(string name)
{
mixin("
      static if (is(" ~ name ~ " == class))
          enum bool isClass = true;
      else
        enum bool isClass = false;");
}

template extractClasses(string moduleName, members...)
{
    alias StaticFilter!(isClass,members) extractClasses;
}

template classMembers(string moduleName)
{
    mixin("alias extractClasses!(moduleName, __traits(allMembers, " ~
moduleName ~ ")) classMembers;");
}


if in module dir.mod1.d you have

class A {}
class B : A {}
struct S {}
class C {}
int foo() { return 0;}

then

classMembers!("dir.mod1") will become the tuple ("A", "B", "C") during
compilation.

It's buggy, though: the module needs to be in a directory. You cannot
do classMembers!("mod1"). Too bad.
Note that class templates are *not* classes. So most of std.* modules
will return an empty tuple, because they're full of templates.
Another detail I didn't have the time to correct: the names should be
tested fully qualified, to avoid any name clash with locally-defined
classes.

As for listing all modules imported by a module, I have something, but
it's not very elegant: it scans the text, looking for import
declarations. It works, but at runtime. I'm not sure it's doable at
compile-time right now: you need to have access to the module code, as
text. Do imports work in CT-evaluable functions?

Philippe
Jan 01 2011
prev sibling next sibling parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 1/1/11, Philippe Sigaud <philippe.sigaud gmail.com> wrote:

 I'm not sure it's doable at
 compile-time right now: you need to have access to the module code, as
 text. Do imports work in CT-evaluable functions?

 Philippe


You're gonna love this:

module mymodule;

void main()
{
    pragma(msg, import(.stringof[7..$] ~ ".d"));
}

Of course, you need to -J switch with the path of your module.
Jan 01 2011
prev sibling next sibling parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
*the* J switch.

On 1/1/11, Andrej Mitrovic <andrej.mitrovich gmail.com> wrote:

 On 1/1/11, Philippe Sigaud <philippe.sigaud gmail.com> wrote:

 I'm not sure it's doable at
 compile-time right now: you need to have access to the module code, as
 text. Do imports work in CT-evaluable functions?

 Philippe


 You're gonna love this:

 module mymodule;

 void main()
 {
     pragma(msg, import(.stringof[7..$] ~ ".d"));
 }

 Of course, you need to -J switch with the path of your module.
Jan 01 2011
prev sibling next sibling parent Philippe Sigaud <philippe.sigaud gmail.com> writes:
On Sat, Jan 1, 2011 at 18:56, Andrej Mitrovic
<andrej.mitrovich gmail.com> wrote:

 On 1/1/11, Philippe Sigaud <philippe.sigaud gmail.com> wrote:

 I'm not sure it's doable at
 compile-time right now: you need to have access to the module code, as
 text. Do imports work in CT-evaluable functions?

 Philippe


 You're gonna love this:

 module mymodule;

 void main()
 {
 =C2=A0 =C2=A0pragma(msg, import(.stringof[7..$] ~ ".d"));
 }


I saw your .stringof trick a few days ago and it made my day :-)
But I didn't know you could text-import at compile-time (with access
for the programmer, I mean. Obviously the compiler can import at CT).
Cool!

OK, then it's doable to get a compile-time list of imported modules
from a module name. Too bad modules are not first class in D: would
they have type, we could return a list of them [std.algorithm,
std.concurrency, ...]



 Of course, you need to -J switch with the path of your module.


I'm not much versed in DMD switches. I'll try and see.

Philippe
Jan 02 2011
prev sibling parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 1/2/11, Philippe Sigaud <philippe.sigaud gmail.com> wrote:

 Of course, you need to -J switch with the path of your module.


 I'm not much versed in DMD switches. I'll try and see.

 Philippe


Well it's a simple switch, really. If the module is in "C:\dev\project\", use:
dmd -JC:\dev\project\

On *nix it's the same, I believe.

http://www.digitalmars.com/d/2.0/dmd-windows.html#switches
http://www.digitalmars.com/d/2.0/dmd-linux.html#switches
Jan 02 2011