Calling method by name.

[Robert Jacques]

On Wed, 02 Feb 2011 12:55:37 -0500, %u <fghf at jhgjhb.com> wrote:

> I know is possible to create an object from its name. It's possible to
> call a method from that object if the name is only known at runtime?
>
> Would something like the following be possible?
>
> string classname, methodname;
> // Ask the user for class and method.
> auto obj = Object.factory(classname);
> invoke(methodname, obj, param1, param2);
>
> Thanks

I've been working on an update to std.variant, which includes a  
compile-time reflection to runtime-reflection system. (See  
https://jshare.johnshopkins.edu/rjacque2/public_html/) From the docs:

Manually registers a class with Variant's runtime-reflection system. Note  
that Variant automatically registers any types it is exposed. Note how in  
the example below, only Student is manually registered; Grade is  
automatically registered by Variant via compile-time reflection of Student.

module example;
class Grade   { real  mark;  }
class Student { Grade grade; }
void main(string[] args) {
     Variant.__register!Student;
     Variant grade = Object.factory("example.Grade");
     grade.mark(96.6);
     assert(grade.mark == 96.6);
}

And dynamic method/field calls are handled via the __reflect(string name,  
Variant[]  args...) method like so:

grade.__reflect("mark",Variant(96.6));
assert(grade.__reflect("mark") == 96.6);