I cannot judge on your proposal as I have not much experience with macros (nor with staged functions). Jameson surely can because he has a clear opinion when to use macros and when not.
I just wanted to make clear that defining the type can be a serious issue. Further I don't really see whats wrong with the following function a() data = read_data_from_file() # I am highly type unstable do_some_hard_computation!(data) # I am type stable end What would I gain if the function a would be typestable. The hard work is done in the inner function. Where you absolutely have a point is that it is currently hard to be sure if the inner function is type stable. Maybe it would be cool if one could annotated functions to be stable and raise an error if not? Cheers Tobi Am Samstag, 3. Januar 2015 16:23:22 UTC+1 schrieb Ariel Keselman: > > But using a function for this is wrong because macros allow you to load > the vector at runtime w/o specifying types and without inner scope > type-instability. So why insisting using a function instead of a macro? The > only scenario I can think of is if the name of the file is only known at > runtime and only inside some type-stable inner scope. But then some > type-stable macro could help getting rid of the mess. I just don't see this > mess happening in julia where you can use staged functions and macros; The > solution would look much different than in C++. It could be coded as some > DSL in a library which only exposes a nice API where you list the expected > types and structure and that's it. Not a single 'if' would leak ;) > > There are no free lunches of course, and yes, you could run into some mess > but that seems would rarely happen. I would argue taht un that case no > other language either can help you (they cant help to get this both fast > clean) -- Julia, that's nothing to be ashemed of ;) > > Now if macros are somehow too constrained for such uses we could have a > tag for functions as "type-unstable" in a form that prevents the type > instability from leaking outside, but of course I'm looking for solutions > within the current Julia state > > >
