nint (short for nix interpreter) is a tiny wrapper around nix-instantiate
which allows to run nix scripts, i. e. nix expressions that conform to
a certain calling convention. A nix script runnable using nint must
conform to the following constraints:
* It must evaluate to a function which has a set pattern with an
ellipsis as the single argument.
* It must produce a string as a return value or fail.
When invoked, a the expression receives the following arguments:
* `currentDir`: the current working directory as a nix path
* `argv`: a list of strings containing `argv` including `argv[0]`
* extra arguments which are manually specified which allows for
passing along dependencies or libraries, for example:
nint --arg depot '(import /depot {})' my-prog.nix [ argv[1] … ]
would pass along depot to be used in `my-prog.nix`.
Such nix scripts are purely functional in a sense: The way inputs can be
taken is very limited and causing effects is also only possible in a
very limited sense (using builtins.fetchurl if TARBALL_TTL is 0,
adding files and directories to the nix store, realising derivations).
As an approximation, a program executed using nint can be thought of
as a function with the following signature:
λ :: environment → working directory → argv → stdout
where environment includes:
* the time at the start of the program (`builtins.currentTime`)
* other information about the machine (`builtins.currentSystem` …)
* environment variables (`builtins.getEnv`)
* the file system (`builtins.readDir`, `builtins.readFile`, …) which
is the biggest input impurity as it may change during evaluation
Additionally import from derivation and builtin fetchers are available
which introduce further impurities to be utilized.
Future work:
* Streaming I/O via lazy lists. This would allow usage of
stdin and output before the program terminates. However this would
require using libexpr directly or writing a custom nix interpreter.
A description of how this would work can be found on the website of the
esoteric programming language Lazy K: https://tromp.github.io/cl/lazy-k.html
* An effect system beyond stdin / stdout.
* Better error handling, support setting exit codes etc.
These features would require either using an alternative or custom
interpreter for nix (tvix or hnix) or to link against libexpr directly
to have more control over evaluation.
Change-Id: I61528516eb418740df355852f23425acc4d0656a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2745
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
We use builtins.split directly as it should be a bit more efficient as
lib.splitStrings. Also its returning of a list for every regex match is
useful to update the state while parsing the tokens:
* The tokens are obtained by splitting the string at every '%'
* Everytime we see a boundary (that is a list in the returned
list of builtins.split), we know that the first two chars of
the next string are a percent encoded character.
One implementation flaw is that it will currently crash if it encounters
mal-formed URLs (since int.fromHex chrashes if it encounters any non
hex digit characters) and accepts some malformed urlencoding like
"foo %A".
Change-Id: I90d08d7a71b16b4f4a4879214abd7aeff46c20c8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2744
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
We make use of the -O man=… option of mandoc(1) which allows to convert
cross references via the .Xr macro into actual hyperlinks in the output.
This can be disabled (by passing "none") or done in two modes:
* all: links all .Xr cross references as if they were in
$out/%N.%S.html. This will lead to broken links of course.
* inManDir: only link to files in $out if the man page is found in
manDir, use the template defined in linkXrFallback if not.
all is the default, since we don't require all man pages to be in
manDir, so it would be potentially confusing if the path attribute was
used in the pages list.
linkXrFallback uses the debian online man viewer by default currently,
since it can be decently hyperlinked and debian has a lot of packages.
Other options would be:
* https://manpages.ubuntu.com/manpages/latest/en/man%S/%N.%S.html
* https://man.archlinux.org/man/%N.%S.en
* https://man.openbsd.org/%N.%S
* https://www.man7.org/linux/man-pages/man%S/%N.%S.html
Change-Id: I1363b9dfdda25cb7383c7310b8115c335444bd3d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2597
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
htmlman is a very simple nix based static site generator which is
intended for rendering HTML representations for man pages plus an index
page listing all available pages. For the sake of simplicity (and unlike
previous iterations of this piece of code) other documentation artifacts
and formats are not supported.
Usually web services like GitHub and depot's web interface are pretty
good at displaying "normal" documentation artifacts like markdown files,
but man pages are usually not rendered — with the additional problem
that it's source is virtually unreadable. htmlman should provide a
simple static site generator which can be plugged into GitHub actions or
the like to automatically generate rendered version of man pages tracked
in version control.
Change-Id: Ib53292964b3ff84c32d70c5fde257a2edb8c2122
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2596
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: Profpatsch <mail@profpatsch.de>
Reviewed-by: sterni <sternenseemann@systemli.org>
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>
switch would probably otherwise be called match, but has been renamed so
it isn't confused with string.match and the enum matching capabilities
yants has.
It implements the closest to pattern matching nix can come which is
still flexible enough to not be painful: Syntactically it works like
cond, but is given a value. Instead of booleans it checks passed
predicates or equality if simple values are passed. Both types of checks
can be mixed.
Change-Id: I40f000979cfd469316e15fd58d6c3a80312c1cc4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2589
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Since nix ends the substring at the end of the string anyways we can
just statically use the largest nix integer as the length of the string.
According to my testing this it ever so slightly faster as well.
Change-Id: I64566e91c7b223f03dcebe3bc5710696dc4261bc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2587
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
This way ci should pick up on clhs-lookup since only a single derivation
is exposed with the default.nix and it is less cumbersome to type the
attribute path (users.sterni.clhs.clhs-lookup →
users.sterni.clhs-lookup). The exposed CLHS wasn't used for anything
anyways and I can always expose it again using passthru or extra if it's
ever merged.
Change-Id: I6c5aeba1b58ca650700c6efa0913e4b42685ea6b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2461
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Probably very similar to M-x sly-hyperspec-lookup: take a list of
common lisp symbols on the command line open the corresponding pages
in a local copy of the hyperspec in $BROWSER. Optionally the paths can
be printed to stdout.
Change-Id: I389e254f14eb0fc8fd8b18a4dbfe7adeeda9ba72
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2397
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
