On Tue, Nov 27, 2012 at 01:34:59PM -0800, Evan Laforge wrote:
I don't totally understand how ghci loading would work. I assume that for external packages it will go load x.so instead of x.a, but what about local modules? I assume ghc -c is still going to produce .o files, so does that mean ghci will have to interpret all local moules?
No, it links them into a temporary .so in /tmp and dlopens that.
On the plus side, it seems like this would do wonders for link time, which is currently about 15s of "machine grinds to a halt" for me. I didn't see mention of it on the page, but I assume linking a binary with lots of giant packages is going to be a lot faster if they can be loaded on demand at runtime... or is just going to make startup really slow?
It looks like it's fractionally slower on x86_64/Linux: Using static libraries with ghci: $ time echo GHC.maxPrecedence | ghc --interactive -package ghc -v0 9 1.00s user 0.12s system 100% cpu 1.122 total Using dynamic libraries with ghci: $ time echo GHC.maxPrecedence | ghc --interactive -package ghc -v0 9 1.01s user 0.15s system 101% cpu 1.141 total Thanks Ian