Context:
I am currently writing a small library that compiles sql strings
at compile-time and generates query objects.
Something like this:
unittest
{
mixin Sql!(q{
select feed.url, feed.title
from users
join user_feeds as feed
on users.id = feed.user
where user.id = {user}
}, DBInterface) UserFeeds;
UserFeeds.Query query;
query.user = 1; //some user
auto con = //Open db connection
auto feeds = con.execute(query);
foreach(f; feeds)
{
writef("Feed: %s\n\tTitle: %s\n", f.url, f.title);
}
}
The parsing step does some amount work like validates the sql
query, makes sure that tables "user" and "user_feed" exists in
DBInterface and creates a query having "user" as input and a
result type containing url, title with appropriate type.
Now the compile times for parsing a small number of queries are
marginal. However, as the queries become more numerous and
complex compile-times starts to become a problem.
Currently I "solve"tm long compile times by having the
DBInterface and queries be compiled into a separate lib and
linking to that lib from the main application.
Having a dedicated db lib fixes compile times for the main
application. But I am wondering if it's possible to work on a
lower level of granularity. Somehow "cache" the queries between
compiles, without resorting to each query being compiled into
it's own lib/object file.
Does D have any facilities that could make this possible?
