This question popped up every once in a while. While already explained
quite well at
https://inbox.tvl.su/depot/20230316120039.j4fkp3puzrtbjcpi@tp/T/#t,
it's not easily accessible.
Lift it from there into tvix/docs for better visibility.
Change-Id: I5f2d4aff31ab4adc421e06a7d36c871f45e09100
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9080
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
This explicitly documents behavior of C++ Nix that goes against the
intuition you'd gather from this document: that e.g. a simple select
from an attribute set causes a value to no longer be pointer equal to
its former self.
The point of documenting this is that we can show in a to be written
section on the use of pointer equality in nixpkgs that pointer equality
is only needed in a limited sense for evaluating it (C++ Nix's exterior
pointer equality). Tvix's pointer equality is far more powerful since
value identity preserving operations also preserve pointer equality,
generally speaking (this is because we implement interior pointer
equality in my made up terminology). This should eventually also be
documented.
Change-Id: I6ce7ef2d67b012f5ebc92f9e81bba33fb9dce7d0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8856
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
I want to expand on the C++ Nix behavior, since it seems relevant to
note that a lot of operations in C++ Nix (like select) don't preserve
pointer equality (see
<https://github.com/NixOS/nix/issues/3371#issuecomment-1596167957>).
It is especially so, as Tvix establishes pointer equality in a different
way and thus shows differing behavior. Therefore I want to additionally
document Tvix's current behavior and make it more explicit to what
extent nixpkgs needs pointer equality.
Change-Id: I9b4ba75dacb749c9fcbba4b9646c6b48bb57bbad
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8852
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Main one is the its-it's mistake in the last paragraph, the rest was
suggested by LanguageTool.
Change-Id: If1b87a11f480452f312fc2759be7ded782d0a522
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7930
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
This was put together by digging through the C++ Nix git history as
described in the second paragraph. Note that this is only based on
changes given when the language version was actually increased.
There is no guarantee that there have been no other changes inbetween
that would have warranted an increase as well.
Change-Id: I4ddee0d4ecafa1b3e5e1a867e9700d6c32e936ad
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7836
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
This extends various ideas around the store and its slightly different
internal model.
Thanks to store composition, lazy substitution and more efficient
transfer, we can also simplify some complicated logic while building.
Change-Id: Ib3380af650fe06e114f54e8dc2df231f18af876b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6585
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
This is only the introductory text, without any of the components
specified so far.
Change-Id: I6cd8eff6ec2daf14cc2420ee0a8e8983bfaa57d9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3052
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: sterni <sternenseemann@systemli.org>
We also want to access the produced SVGs separately.
Change-Id: I5bdfd95b8a56323ed8bf5f4585b703f6e728c677
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2742
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Most other docs folders in the repo are called `doc` too, let's make
this consistent.
Change-Id: Icd712429b51763076548c977321e370f2a77877e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2741
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>