Bug reports [Was: Re: About Andrei's interview, part 3]

[Andrej Mitrovic]

Wouldn't it be better if we had some kind of compile-time block
statement instead of making separate compile-time keywords for every
run-time keyword?

For example, we could reuse static, and instead of code like this from
std.range:

private template MostDerivedInputRangeImpl(R) {
    private alias ElementType!R E;

    static if(isRandomAccessRange!R) {
        static if(isInfinite!R) {
            alias RandomAccessInfinite!E ret;
        } else static if(hasAssignableElements!R) {
            alias RandomFiniteAssignable!E ret;
        } else {
            alias RandomAccessFinite!E ret;
        }
    } else static if(isBidirectionalRange!R) {
        static if(hasAssignableElements!R) {
            alias BidirectionalAssignable!E ret;
        } else {
            alias BidirectionalRange!E ret;
        }
    } else static if(isForwardRange!R) {
        static if(hasAssignableElements!R) {
            alias ForwardAssignable!E ret;
        } else {
            alias ForwardRange!E ret;
        }
    } else {
        static if(hasAssignableElements!R) {
            alias InputAssignable!E ret;
        } else {
            alias InputRange!E ret;
        }
    }
}

We would have this:

private template MostDerivedInputRangeImpl(R) {
    private alias ElementType!R E;

    static {
         if(isRandomAccessRange!R) {
            if(isInfinite!R) {
                alias RandomAccessInfinite!E ret;
            } else if(hasAssignableElements!R) {
                alias RandomFiniteAssignable!E ret;
            } else {
                alias RandomAccessFinite!E ret;
            }
        } else if(isBidirectionalRange!R) {
            if(hasAssignableElements!R) {
                alias BidirectionalAssignable!E ret;
            } else {
                alias BidirectionalRange!E ret;
            }
        } else if(isForwardRange!R) {
            if(hasAssignableElements!R) {
                alias ForwardAssignable!E ret;
            } else {
                alias ForwardRange!E ret;
            }
        } else {
             if(hasAssignableElements!R) {
                alias InputAssignable!E ret;
            } else {
                alias InputRange!E ret;
            }
        }
    }
}

Or maybe use a different name for a compile-time block to not conflict
with static.


On Fri, Aug 27, 2010 at 2:42 AM, bearophile <bearophileHUGS at lycos.com> wrote:
>
> Steps toward a static foreach
> (just the first point is enough for now)
> http://d.puremagic.com/issues/show_bug.cgi?id=4085