Are you tired of D's sane, straightforward scoping rules? Itching for a taste of that old-fashioned C++ madness? Well, itch no more: addle is here to help.

addle is a tiny library that implements C++-style argument-dependent lookup (ADL) for D, on an opt-in basis. It lets you extend existing types with UFCS methods, and share those methods seamlessly with code in other modules--no `import` required!

Here's a brief example:

    import addle;
    import std.range;

    // Import a type from another module
    import mylib: MyStruct;

    // Define range primitives for MyStruct
    bool empty(MyStruct a) { return false; }
    string front(MyStruct a) { return "ok"; }
    void popFront(MyStruct a) {}

    // MyStruct isn't considered an input range, because
    // std.range can't see our UFCS methods.
    static assert(isInputRange!MyStruct == false);

    // ...but extending it makes those methods visible.
    static assert(isInputRange!(Extended!MyStruct));

    void main()
    {
        import std.range: take, only;
        import std.algorithm: equal;

        MyStruct myStruct;

        // Now we can use all of the standard range algorithms
        assert(
            myStruct.extended
            .take(3)
            .equal(only("ok", "ok", "ok"))
        );
    }

Now available on Dub, by "popular demand"!

Links:
  - Documentation: https://addle.dpldocs.info/addle.html
  - Dub: https://code.dlang.org/packages/addle
  - Github: https://github.com/pbackus/addle

On Sunday, 21 June 2020 at 00:06:12 UTC, Paul Backus wrote:
> Now available on Dub, by "popular demand"!
>
> Links:
>   - Documentation: https://addle.dpldocs.info/addle.html
>   - Dub: https://code.dlang.org/packages/addle
>   - Github: https://github.com/pbackus/addle

Cool. Thanks.

On Sunday, 21 June 2020 at 00:06:12 UTC, Paul Backus wrote:
>     import addle;
>     import std.range;
>
>     // Import a type from another module
>     import mylib: MyStruct;
>
>     // Define range primitives for MyStruct
>     bool empty(MyStruct a) { return false; }
>     string front(MyStruct a) { return "ok"; }
>     void popFront(MyStruct a) {}
>
>     // MyStruct isn't considered an input range, because
>     // std.range can't see our UFCS methods.
>     static assert(isInputRange!MyStruct == false);
>
>     // ...but extending it makes those methods visible.
>     static assert(isInputRange!(Extended!MyStruct));
>
>     void main()
>     {
>         import std.range: take, only;
>         import std.algorithm: equal;
>
>         MyStruct myStruct;
>
>         // Now we can use all of the standard range algorithms
>         assert(
>             myStruct.extended
>             .take(3)
>             .equal(only("ok", "ok", "ok"))
>         );
>     }

As a demonstration of what you can do in D, I love this. Maybe one day I'll even find a use for it. Good work!

--
  Simen

On Sunday, 21 June 2020 at 00:06:12 UTC, Paul Backus wrote:
> Are you tired of D's sane, straightforward scoping rules? Itching for a taste of that old-fashioned C++ madness? Well, itch no more: addle is here to help.
>
> addle is a tiny library that implements C++-style argument-dependent lookup (ADL) for D, on an opt-in basis. It lets you extend existing types with UFCS methods, and share those methods seamlessly with code in other modules--no `import` required!
>
> Here's a brief example:
>
>     import addle;
>     import std.range;
>
>     // Import a type from another module
>     import mylib: MyStruct;
>
>     // Define range primitives for MyStruct
>     bool empty(MyStruct a) { return false; }
>     string front(MyStruct a) { return "ok"; }
>     void popFront(MyStruct a) {}
>
>     // MyStruct isn't considered an input range, because
>     // std.range can't see our UFCS methods.
>     static assert(isInputRange!MyStruct == false);
>
>     // ...but extending it makes those methods visible.
>     static assert(isInputRange!(Extended!MyStruct));
>
>     void main()
>     {
>         import std.range: take, only;
>         import std.algorithm: equal;
>
>         MyStruct myStruct;
>
>         // Now we can use all of the standard range algorithms
>         assert(
>             myStruct.extended
>             .take(3)
>             .equal(only("ok", "ok", "ok"))
>         );
>     }
>
> Now available on Dub, by "popular demand"!
>
> Links:
>   - Documentation: https://addle.dpldocs.info/addle.html
>   - Dub: https://code.dlang.org/packages/addle
>   - Github: https://github.com/pbackus/addle

That's pretty neat.

I wonder if something like that could have been used when checking types in phobos? Probably wouldn't be implemented as I can imagine a performance impact during compilation tho.