This displays how users can configure an impure evaluation for
tvix-serde, which makes it possible to use e.g. `nixpkgs/lib`.
We might want to add an example showing how the full Nix-glue
compatibility stuff can be added here, too.
Change-Id: I2224a3fc66e739969d4c723c3d9d8127a046b6fd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10994
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Makes use of the SourceCode field now being stored directly in
errors (see parent CL). With this change, the default `Display`
implementation can now format errors correctly, and there is no need
to keep a `SourceCode` around just for error formatting.
Updates dependent crates (CLI, serde, tvixbolt) to use this correctly.
Change-Id: Iddc5d7a6b4bab391f30a999e4c68aca34304c059
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10987
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
NixString is *quite* large - like 80 bytes - because of the extra
capacity value for BString and because of the context. We want to keep
Value small since we're passing it around a lot, so let's box the
NixString inside Value::String to save on some memory, and make cloning
ostensibly a little cheaper
Change-Id: I343c8b4e7f61dc3dcbbaba4382efb3b3e5bbabb2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10729
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
C++ nix uses C-style zero-terminated char pointers to represent strings
internally - however, up to this point, tvix has used Rust `String` and
`str` for string values. Since those are required to be valid utf-8, we
haven't been able to properly represent all the string values that Nix
supports.
To fix that, this change converts the internal representation of the
NixString struct from `Box<str>` to `BString`, from the `bstr` crate -
this is a wrapper around a `Vec<u8>` with extra functions for treating
that byte vector as a "morally string-like" value, which is basically
exactly what we need.
Since this changes a pretty fundamental assumption about a pretty core
type, there are a *lot* of changes in a lot of places to make this work,
but I've tried to keep the general philosophy and intent of most of the
code in most places intact. Most notably, there's nothing that's been
done to make the derivation stuff in //tvix/glue work with non-utf8
strings everywhere, instead opting to just convert to String/str when
passing things into that - there *might* be something to be done there,
but I don't know what the rules should be and I don't want to figure
them out in this change.
To deal with OS-native paths in a way that also works in WASM for
tvixbolt, this also adds a dependency on the "os_str_bytes" crate.
Fixes: b/189
Fixes: b/337
Change-Id: I5e6eb29c62f47dd91af954f5e12bfc3d186f5526
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10200
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: aspen <root@gws.fyi>
Tested-by: BuildkiteCI
Have a Evaluation::new() function that's used to set up the Evaluation
struct initially - which is also used by both new_pure and new_impure
internally.
It's generic over the exact type of IO, making it easier to instantiate
Evaluation with non-tvix-eval EvalIO implementations, that might not be
in a Box.
Change-Id: Ibf728da24aca59639c5b6df58d00ae98c99a63f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10640
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Don't restrict to a Box<dyn EvalIO>.
There's still one or two places where we do restrict, this will be
solved by b/262.
Change-Id: Ic8d927d6ea81fa12d90b1e4352f35ffaafbd1adf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10639
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Instead, it's passed in the evaluate/compile_only functions, which feels
more naturally. It lets us set up the Evaluation struct long before
we actually feed it with data to evaluate.
Now that Evaluation::new() would be accepting an empty list of
arguments, we can simply implement Default, making things a bit more
idiomatic.
Change-Id: I4369658634909a0c504fdffa18242a130daa0239
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10475
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
This commit makes catchable errors a variant of Value.
The main downside of this approach is that we lose the ability to
use Rust's `?` syntax for propagating catchable errors.
Change-Id: Ibe89438d8a70dcec29e016df692b5bf88a5cad13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9289
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
The change allows applications that use tvix_serde for parsing
nix-based configuration to extend the language with domain-specific
set of features.
Change-Id: Ia86612308a167c456ecf03e93fe0fbae55b876a6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8848
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
When dealing with a formal argument in a function argument pattern that
has a default expression, there are two different things that can happen
at runtime: Either we select its value from the passed attribute
successfully or we need to use the default expression. Both of these may
be thunks and both of these may need finalisers. However, in the former
case this is taken care of elsewhere, the value will always be finalised
already if necessary. In the latter case we may need to finalise the
thunk resulting from the default expression. However, the thunk
corresponding to the expression may never end up in the local's stack
slot. Since finalisation goes by stack slot (and not constants), we need
to prevent a case where we don't fall back to the default expression,
but finalise anyways.
Previously, we worked around this by making `OpFinalise` ignore
non-thunks. Since finalisation of already evaluated thunks still
crashed, the faulty compilation of function pattern arguments could
still cause a crash.
As a new approach, we reinstate the old behavior of `OpFinalise` to
crash whenever encountering something that is either not a thunk or
doesn't need finalisation. This can also help catching (similar)
miscompilations in the future. To then prevent the crash, we need to
track whether we have fallen back or not at runtime. This is done using
an additional phantom on the stack that holds a new `FinaliseRequest`
value. When it comes to finalisation we check this value and
conditionally execute `OpFinalise` based on its value.
Resolves b/261 and b/265 (partially).
Change-Id: Ic04fb80ec671a2ba11fa645090769c335fb7f58b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8705
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
This adds a `from_str_with_config` function which takes a
user-supplied closure that sets additional settings on the
`tvix_eval::Evaluation`.
Note that users can not set `strict = false`, but other settings are
not restricted.
This solves b/262.
Change-Id: Ice184400b843cfbcaa5b6fe251ced12b6815e085
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8808
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This makes it possible for callers to control whether they can receive
partially evaluated values from an evaluation or not.
We're actually flipping the default behaviour to non-strict top-level
evaluation, which means that callers have to set `strict = true` on
the Evaluation to get the previous behaviour.
Change-Id: Ic048e9ba09c88866d4c3177d5fa07db11c4eb20e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8325
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
This drops the usage of serde::Serialize, as the trait can not be used
to implement the correct semantics (function colouring!).
Instead, a manual JSON serialisation function is written which
correctly handles toString, outPath and other similar weirdnesses.
Unexpectedly, the eval-okay-tojson test from the C++ Nix test suite
now passes, too.
This fixes an issue where serialising data structures containing
derivations to JSON would fail.
Change-Id: I5c39e3d8356ee93a07eda481410f88610f6dd9f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8209
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
This is an example, which uses the debug trait to print all field
values.
Silence the compiler warning about unused fields.
Change-Id: I5f1216c77819003302e83ba1af1ff13c924f3b38
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7971
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
This shows how people can use tvix_serde to deserialise configuration
structs for their programs from Nix code.
Change-Id: I71bf4e03dce19dddafe67dd729b4e4b10719a739
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7945
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Implements externally tagged enum deserialisation. Other serialisation
methods are handled by serde internally using the existing methods.
See the tests for examples.
Change-Id: Ic4a9da3b5a32ddbb5918b1512e70c3ac5ce64f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7721
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Only missing enums at this point, but they're a bit of a beast.
Change-Id: I4ad47c034851f9a8794c81f39a5149a8ac1826e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7716
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
This will make it possible fairly easily use Nix to represent
arbitrary data structures, e.g. for using Nix as a config language.
Only pure Nix (i.e. no `import` etc.) is supported for now.
Not all types, specifically no struct traversal, are implemented in
this commit.
Change-Id: I9ac91a229a0d12bf818e6e3249f3e5a691599a2c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7712
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
