Naming methods from strings using mixin

[Adam D. Ruppe]

On Tuesday, 21 February 2012 at 14:53:06 UTC, Robert Rouse wrote:
> Using a mixin, is it possible to have it define a method based 
> on a string passed into the mixin?

Yeah, though you'll have to build a string of the method.

Something like this:

string make_method_string(string name) {
     string code = "void "; // return type
     code ~= name;
     code ~= "() {"; // arglist
     code ~= q{ // body (q{ } is just another string literal but 
prettier for this imo
          writeln("hello");
     };
     code ~= "}";
     return code;
}

mixin template make_method(string name) {
        mixin(make_method_string(name)); // string mixin runs the 
above function at compile time, and then pastes the resulting 
code in here to be compiled
}


// and now  to use it

struct Test {
    mixin make_method("bark");
}


void main() {
    Test foo;
    foo.bark(); // works!
}





The string mixin and string builder helper function pattern
can do pretty much anything you can think up, though it can
get pretty ugly as it gets bigger just due to being strings.