Closes#9343
See that issue for motivation.
Installing these is disabled by default, but we enable it (and the
additional output we want isntall these too so as not to clutter the
existing ones) to use in cross builds and dev shells.
Try to stay away from stack overflows.
These small vectors use stack space. Most instances will not need
to allocate because in general most things are small, and large
things are worth heap allocating.
16 * 3 * word = 384 bytes is still quite a bit, but these functions
tend not to be part of deep recursions.
This makes stack usage significantly more compact, allowing larger
amounts of data to be processed on the same stack.
PrimOp functions with more than 8 positional (curried) arguments
should use an attrset instead.
VLAs are a dangerous feature, and their usage triggers an undefined
behavior since theire size can be zero in some cases.
So replace them with `boost::small_vector`s which fit the same goal but
are safer.
It's also incidentally consistently 1% faster on the benchmarks.
This is the core functionality but just unit-tested and not yet made
part of the store layer. This is because there is some tech debt around
(a) repeated boilerplate hashing objects (b) better integration of the
new `SourceAccessor` type that needs to be cleaned up first.
Part of RFC 133
Co-Authored-By: Matthew Bauer <mjbauer95@gmail.com>
Co-Authored-By: Carlo Nucera <carlo.nucera@protonmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Florian Klink <flokli@flokli.de>
As discussed in our last meeting, we need a bit more time, but we are
"time boxing" the work left to do to ensure there is not unbounded
delay.
Rather than putting it back underneath `flakes`, though, put it
underneath its own `fetch-tree` experimental feature (which `flakes`
includes/implies). This signals our commitment to the plan to stabilize
it first without waiting to go through the rest of Flakes, and also will
give users a "release candidate" when we get closer to stabilization.
This reverts commit 4112dd1fc9.
These usages of the working directory are perhaps unlikely to
interact with shebangs, but the code is more consistent this way,
and we're less likely to miss usages that do interact.
