Improve spec/function#lazy-params example

[PetarKirov]

To better showcase the D's expressiveness.

[dlang-bot]

Thanks for your pull request, @ZombineDev!

Bugzilla references

Your PR doesn't reference any Bugzilla issue.

If your PR contains non-trivial changes, please reference a Bugzilla issue or create a manual changelog.

[PetarKirov]

@jacob-carlborg @thewilsonator can you guys help me debug the ddoc failure? I tried various things locally ~2 months ago, but it always seemed to fail for no reason.

[thewilsonator]

this is using SPEC_RUNNABLE_EXAMPLE_COMPILE which I have just discovered in #2507 wraps a void main(){ ... } around the example. so that code becomes

void main()
{
    import std.stdio : writeln;

    void main()
    {
        int x;
        3.times(writeln(x++)); // <<< fails here
        writeln("-");
        writeln(x);
    }

    void times(int n, lazy void exp)
    {
        while (n--)
            exp();
    }
}

which for me fails with Error: no property times for type int, presumably because times is nested. Whats with all the LaTeX failures, I have no idea. Maybe it confuses the macros. Either way it doesn't look like you will be able to show off 3.times(writeln(x++)); with SPEC_RUNNABLE_EXAMPLE_COMPILE , you'd have to do a no main wrapping version.

[PetarKirov]

Thanks for looking into this @thewilsonator. Actually I had gotten only so far as the LaTeX problems and I haven't even considered the the problem with SPEC_RUNNABLE_EXAMPLE_COMPILE. I propose we add SPEC_RUNNABLE_EXAMPLE_COMPILE_CUSTOM_MAIN version which would not try to wrap the code in another main(). I'll see if that's easy to do when I have some free time on my hands.

[wilzbach]

I propose we add SPEC_RUNNABLE_EXAMPLE_COMPILE_CUSTOM_MAIN version which would not try to wrap the code in another main(). I'll see if that's easy to do when I have some free time on my hands.

Please don't. The script already checks for void main. Better to fix that, but looking on this from my phone I don't think that's the root cause. We have had tons of problems with the function page getting too big and thus LaTeX throwing weird errors.

[thewilsonator]

The script already checks for void main.

Good to know

Better to fix that, but looking on this from my phone I don't think that's the root cause. We have had tons of problems with the function page getting too big and thus LaTeX throwing weird errors.

Ahh, right.

[wilzbach]

It could be related to the - and LaTeX not liking it (though I can't build the PDF at the moment either), but I tested this commit here.

[PetarKirov]

Thanks!