users.sterni.nix.utf8 implements UTF-8 decoding in pure nix. We
implement the decoding as a simple state machine which is fed one byte
at a time. Decoding whole strings is possible by subsequently calling
step. This is done in decode which uses builtins.foldl' to get around
recursion restrictions and a neat trick using builtins.deepSeq puck
showed me limiting the size of the thunks in a foldl' (which can also
cause a stack overflow).
This makes decoding arbitrarily large UTF-8 files into codepoints using
nix theoretically possible, but it is not really practical: Decoding a
36KB LaTeX file I had lying around takes ~160s on my laptop.
Change-Id: Iab8c973dac89074ec280b4880a7408e0b3d19bc7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2590
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
After all it only matches strings.
Change-Id: I3d2e5221ef43f692de69028e78ed98b6b11f82d1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2586
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
What you see here is mostly the fallout of me implementing a correct
urlencode implementation in nix for Profpatsch's blog implementation
(although they'll probably keep it at arm's length).
Where I want to go from here:
* Extend this library towards general purpose nix™, mainly by
implementing missing interfaces which you'd still have to use
<nixpkgs/lib> for right now. Reexposing parts of <nixpkgs/lib>
with better naming is fine for now, at some point I'd contemplate
making this depend on nothing outside of depot, maybe even itself
(should be easy we only use yants for an easily replaceable check).
* Improve error messages possibly by carefully reintroducing yants. I
originally typed essentially everything using yants, but turns out
this can a) be dangerous when stuff you are handling throws because
type checking means evaluating and b) has a incredible performance
cost in some cases.
* Reexpose builtins with better naming and slightly wrapped so they
don't unrecoverably throw in cases where a null or something would
suffice.
Change-Id: I33ab08ca4e62dbc16b86c66c653935686e6b0e79
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2541
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI
