22-Dec-2013 08:23, Andrei Alexandrescu пишет:
On 12/21/13 1:38 PM, Dmitry Olshansky wrote:
As it stands the only thing lazy buys us is "pay as you touch" contrary
to "pay as you name the intent to touch". The problem is that the
payment is for the whole stock of the said "shop". I see second problem
(granularity of imports) as far more critical then the first (condition
under which the pieces are imported). The second problem seems solvable
within the current implementation, the first seems like it would need
arbitrary amount of time to fix and gains are marginal.
The way I see it is we can improve the compilation speed for everyone
without having them change the code in any way, as opposed to toiling
over phobos to the benefit of nothing else but phobos.
Because of poor organization of Phobos we have to. Anyhow work on std
library is a major benefit to everyone who uses it (including
compilation speed). And nobody have to change code to get the benefits
e.g. the proverbial size of hello world is going to be smaller (you
surely recall that recent problem).
Unlike Phobos many projects already have sane package structure but the
moment they use this tiny primitive (e.g. writeln) in Phobos compile
times drop.
Which is the
better win?
I'd take both :o)
I'm not against lazy imports per see. The problem is that the "instant"
benefit is going to be smaller then you seem to imply. I'd like to be
proven otherwise but there is no experimental compiler to see yet.
If Phobos stays pretty much as is lazy imports is just a new
(potentially slow and bogus) feature. And we know how new stuff works -
see -allinst switch. On the other hand restructuring Phobos is a bonus
that users don't have to suffer for.
--
Dmitry Olshansky
