Commit graph

933 commits

Author SHA1 Message Date
Vincent Ambo
7cfdedfdfb feat(tvix/eval): compile with expression
Adds an additional structure to the compiler's scope to track the
runtime "with stack", i.e. the stack of values through which
identifiers should be dynamically resolved within a with-scope.

When encountering a `with` expression, the value from which the
bindings should be resolved is pushed onto the stack and tracked by
the compiler in the "with stack", as well as with a "phantom value"
which indicates that the stack contains an additional slot which is
not available to users via identifiers.

Runtime handling of this is not yet implemented.

Change-Id: I5e96fb55b6378e8e2a59c20c8518caa6df83da1c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6217
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-31 22:26:11 +00:00
Vincent Ambo
ec7db0235f refactor(tvix/eval): rename Locals to Scope
This name is much more sensible actually; its more than just a
collection of locals as it tracks additional scope information in the
case of Nix.

Change-Id: Ia2739bbd39aab222b1c4355e9248828973b0db43
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6216
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-31 22:10:40 +00:00
Vincent Ambo
f173161f4c feat(tvix/eval): implement inherit in let expressions
Note that at this point recursive bindings do not yet work in either
attrsets or let, so inheriting from the same scope is generally not
possible yet.

Change-Id: I6ca820d04b8ded5c22fb7ea18e2ec203bcaa8e9c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6215
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-31 22:10:40 +00:00
Vincent Ambo
8c1c9aee3c feat(tvix/eval): implement inherit in attribute set literals
Straightforward implementation, evaluating the elements of an inherit
and preparing the stack so that `OpAttrs` sees all relevant values
when constructing the attribute set itself.

The emitted instructions for inheriting a lot of values from the same
attribute set are inefficient, but it's too early to say whether this
actually matters.

Change-Id: Icb55a20936d4ef77173f34433811c5fa5d2c9ecc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6214
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-31 22:10:40 +00:00
Vincent Ambo
7db4f8d774 fix(tvix/eval): gently attempt to create state dir
If the directory in which REPL history is stored does not exist,
gently try to create it, but do not raise an error if it doesn't work.

We may want to warn about it, but in general this sort of
non-essential feature should not cause a hard failure.

Change-Id: If4fe8db0c7893c39627efe72c9cd9ebf7ed63f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6213
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-31 22:10:40 +00:00
Vincent Ambo
e07556493f feat(tvix/eval): Implement inherit from outer scope in attrs
Change-Id: I97fa45059b7f2cbe96eb60bd1821e3e25832df66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6212
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
3a67f91228 fix(tvix/eval): ? operator should use OpAttrsOrNotFound
Using `OpAttrSelect`, the ? operator will fail when encountering a
nested value that is not an attribute set.

This however breaks valid code, such as:

  { bs = 42; } ? bs.a.b

The fix is simply to use the same operator used in the `or` statement,
which leaves a sentinal on the stack if a field is not found or the
value is not an attribute set.

Change-Id: Ib28fc8a96e6d592b4cdbc3e65ba129ad8faecd66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6211
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
cfe37d36f7 fix(tvix/eval): or should handle non-attrset values, too
If a nested attrpath encounters a non-set value, the sentinel value
denoting a lack of next values should be emitted. This mirrors the
behaviour of Nix.

Change-Id: Ia80443d5a11243cc6d98dcab1249a3f5fdf77e27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6210
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
76846fe220 fix(tvix/eval): allow use of ? operator on non-set types
Nix allows this, but always returns false. Tvix needs to do the same.

Change-Id: Ic9eec90834a0d0969eea5316d5c25032d3691d94
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6209
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
43658a5b90 fix(tvix/eval): emit correct count in OpAttrPath
Not sure how exactly this snuck in, but it caused some subtle
breakages in deeply nested attribute sets.

Change-Id: I8049ce912405d3750031f79cc8d86ff1c3c02c2b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6208
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
8d45fbadea docs(tvix/eval): Use correct syntax for module doc comments
Change-Id: I35741856f34b86a538f226a8eaf8806edede60ec
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6207
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
11ea7b82d8 chore(tvix/eval): minor readability improvement in attrs
Change-Id: If9d9eaf60934e96ec4b41c57818afe0c2a99c862
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6206
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
de26894814 refactor(tvix/eval): remove Error::InvalidKeyType
We're confident that we're handling all branches that can reasonably
occur from valid AST, any other cases should be considered a critical
evaluator bug and panic rather than surfacing something that looks
like user error.

Change-Id: If96966eb32b8ff12fcaeb9ea3b0c8fc51b6abd11
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6205
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-30 17:13:27 +00:00
Vincent Ambo
ab9407bded fix(tvix/eval): address various clippy lints
Change-Id: I3ea0f51475e80948adfeb5d1620c1f2665cc39bc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6201
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-30 16:53:40 +00:00
Vincent Ambo
c4f73eecdc feat(tvix/eval): implement attribute set equality
Change-Id: Ia25f02610f2575e5e7fca81643e05b40f4a07820
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6200
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-30 16:53:40 +00:00
Vincent Ambo
2ea71aa4c3 fix(tvix/eval): null in dynamic attribute keys skips the element
This is actually *tested* behaviour in C++ Nix, so we need to
implement it here, too.

Change-Id: Ic4a4659a2f04cdd928cbe78a85dae90401515371
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6199
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-30 16:53:40 +00:00
Vincent Ambo
e041851581 feat(tvix/eval): implement chunk disassembler output
This makes for a much nicer view of an execution if `--feature
disassembler` is set, for example:

  tvix-repl> let value = [ 1 2 { a = 1; } ]; in value ++ [ 1 ]
  === compiled bytecode (11 operations) ===
  02   OpConstant(1)
  02   OpConstant(2)
  02   OpConstant("a")
  02   OpConstant(1)
  02   OpAttrs(1)
  02   OpList(3)
  02   OpGetLocal(0)
  02   OpConstant(1)
  02   OpList(1)
  02   OpConcat
  02   OpCloseScope(1)
  === runtime trace ===
  0001 OpConstant(ConstantIdx(0))  [ 1 ]
  0002 OpConstant(ConstantIdx(1))  [ 1 2 ]
  0003 OpConstant(ConstantIdx(2))  [ 1 2 "a" ]
  0004 OpConstant(ConstantIdx(3))  [ 1 2 "a" 1 ]
  0005 OpAttrs(1)                  [ 1 2 { a = 1; } ]
  0006 OpList(3)                   [ [ 1 2 { a = 1; } ] ]
  0007 OpGetLocal(0)               [ [ 1 2 { a = 1; } ] [ 1 2 { a = 1; } ] ]
  0008 OpConstant(ConstantIdx(4))  [ [ 1 2 { a = 1; } ] [ 1 2 { a = 1; } ] 1 ]
  0009 OpList(1)                   [ [ 1 2 { a = 1; } ] [ 1 2 { a = 1; } ] [ 1 ] ]
  0010 OpConcat                    [ [ 1 2 { a = 1; } ] [ 1 2 { a = 1; } 1 ] ]
  0011 OpCloseScope(1)             [ [ 1 2 { a = 1; } 1 ] ]
  => [ 1 2 { a = 1; } 1 ] :: list

Change-Id: If79c7fd1f0f18255ddb3763c1ba585fda8041b1b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6195
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-30 16:53:40 +00:00
Vincent Ambo
57d0dbb1c6 feat(tvix/eval): implement optional runtime tracing
This adds a `disassembler` feature to the crate configuration that
traces the operations executed and the state of the stack at runtime.

This can be enabled by compiling with `--feature disassembler`.

This will also gain a more sensible layout of code slices eventually.

Change-Id: I34c15e1cd346ecc4362b5afba6bf82dd49359d20
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6193
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-30 16:53:40 +00:00
Vincent Ambo
1cb1931406 feat(tvix/eval): emit warnings on useless inherit
Change-Id: Ifb9993cf8b85393eb43e1b204c7ab2f889b7113b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6194
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-29 20:13:26 +00:00
Vincent Ambo
ab12b0abff fix(tvix/eval): skip inherit with no explicit parent in let
Using `inherit` in a let-binding can not possibly have an effect, as
the given identifier is already bound exactly the same way in the
current scope.

This introduces a subtle bug that is fixed later on, as there
actually *is* a (single) condition where these inherits are
meaningful.

Change-Id: I8b24f0edcfe80db8153bb7e86cf478d36957d6f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6192
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-29 20:13:26 +00:00
Vincent Ambo
36748fe4f6 test(tvix/eval): add basic tests for let expressions
Change-Id: I788504f0c1848a1422c99006bf659738df614716
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6191
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-29 20:13:26 +00:00
Vincent Ambo
342b233a0a feat(tvix/eval): add local identifier access
This makes basic `let ... in ...` statements work correctly. It does
not yet account for the call frames pushed into the VM during function
application.

Change-Id: I67155171daf1a43011b96716dd9d1ab04b27db33
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6190
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-28 17:50:34 +00:00
Vincent Ambo
2d401a32e5 feat(tvix/eval): detect dynamic identifier names in let
Nix does not allow dynamic identifiers in let expressions (only in
attribute sets), but there are several different kinds of things it
considers static identifiers.

The functions introduced here put the path components of a let
expression into normalised (string) form, and surface an error about
dynamic keys if one is encountered.

Change-Id: Ia3ebd95c6f3ed3cd33b94e156930d2e9c39b6cbf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6189
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-28 17:50:34 +00:00
Vincent Ambo
691a596aac feat(tvix/eval): compile simple let ... in ... expressions
These expressions now leave the binding values on the stack, and clean
up the scope after the body of the expression.

While variable access is not yet implemented (as the identifier node
remains unhandled), this already gives us the correct stack behaviour.

Change-Id: I138c20ace9c64502c94b2c0f99a6077cd912c00d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6188
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-28 17:50:34 +00:00
Vincent Ambo
bbad338017 feat(tvix/eval): prepare structures for simulating locals stack
These are going to be used during compilation of `let`-expressions to
determine stack offsets for local variables.

Change-Id: Ibb79f3f1ae86650303f88eacf623ae456458de87
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6187
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-28 17:50:34 +00:00
Vincent Ambo
de21d201ba fix(tvix/eval): use path_clean instead of fs::canonicalize for paths
Canonicalisation performs much more functionality than what C++ Nix
implements for paths, and causes some undesirable behaviour (e.g.
handling non-existant files becomes difficult, but should be possible
in literals).

Instead, the path_clean crate provides a pure normalisation method.

There is an intention to add this to Rust itself:
https://github.com/rust-lang/rfcs/issues/2208

Change-Id: I775d238136db0a52cf6b12a68985833c8fb32882
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6186
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-28 11:02:15 +00:00
Vincent Ambo
6fe5e2d752 feat(tvix/eval): resolve relative path literals
Resolves relative paths (e.g. `./foo`) either relative to the location
of the Nix file, or relative to the working directory if none is
supplied.

Change-Id: I70ec574657b221b458015117a004b6e4a9c25a30
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6185
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-28 11:02:15 +00:00
Vincent Ambo
1f8aad0ab4 refactor(tvix/eval): implement error variant for path resolution
There are multiple things that can theoretically fail while resolving
a path, as some of it includes I/O. A new error variant has been added
for this and appropriate errors have been introduced.

Change-Id: Ie222245425207dabbf203166eb5ed1eec0114483
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6184
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-28 11:02:15 +00:00
Vincent Ambo
e68b6d33b0 feat(tvix/eval): support absolute and home-anchored paths
These two paths are the easiest to handle, as they are simply built up
from the components supplied in the text node and then normalised.

Note that the normalisation of fs::canonicalize includes symlink
resolution, which Nix does not actually do. We will need to fix that
at some point.

Change-Id: I54158f0684f197dd2a2583f7d0982d54c7619993
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6183
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-28 11:02:15 +00:00
Vincent Ambo
bf10c35201 chore(tvix/eval): add variant_size_differences warning to Value
Change-Id: I2f4719a81512a9a970edf22390afed490125bda7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6182
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-27 09:27:13 +00:00
Vincent Ambo
e33eaa2cb5 feat(tvix/eval): add Path representation to Value enum
Change-Id: I4827384201912131ea8fc2362188dcd862b94852
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6181
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-27 09:27:13 +00:00
Vincent Ambo
1d86c4537e refactor(tvix/eval): use write! macro instead of f.write_fmt
grfn pointed out in cl/6082 that this is actually the desugaring of
the write! macro, so it doesn't make sense to  write it out.

Change-Id: If7c055b042ad22b034722aec1eaadba92736d684
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6180
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-27 09:27:13 +00:00
Vincent Ambo
0a09356f82 refactor(tvix/eval): rename Chunk::add_* functions to ::push_*
grfn pointed out in cl/6069 that naming them like this makes it clear
that things are being added to the end of the state.

Change-Id: I6a23215c4fef713869a3c85b0dde1ebbda7637e9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6179
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-27 09:27:13 +00:00
Vincent Ambo
4c9d3fa2a6 chore(tvix/eval): explicitly set #[repr(transparent)] on wrappers
For representation wrappers that are used to control the visibility of
type internals, this ensures that the wrapper does not increase the
size of the type.

In practice, the optimiser likely does this anyways but it is good to
guarantee it.

Change-Id: Ic6df7d668fe6006dfbd5b6cfcfc2088afa95b810
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6178
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-27 09:27:13 +00:00
sterni
4523703a98 test(tvix/eval): make sure all language tests also pass with C++ Nix
Change-Id: I8428a82db9bf7af5c0273178acbf3e4d7355f5d9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6153
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-08-26 20:46:03 +00:00
Vincent Ambo
d952b29fca chore(tvix/eval): add variant_size_differences warning for OpCode
This makes it possible to quickly detect code errors that might blow
up the size of the OpCode type.

Change-Id: I7662dd0aa30c4762c0f9e4fa346418c9ca8b9994
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6177
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 20:32:12 +00:00
Vincent Ambo
598c197422 feat(tvix/eval): add warning for deprecated URL literals
Change-Id: I8a9cfcb5d99680344ee0e3461a4a52526b846c92
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6175
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 17:19:51 +00:00
Vincent Ambo
7e77972d71 feat(tvix/eval): add mechanism for emitting warnings from compiler
These can be used predominantly to emit warnings about things that the
compiler can infer, such as deprecated language features.

Change-Id: I3649c625459d7f3f95cdf42d5c651d23d66569ec
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6174
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-26 17:19:51 +00:00
Vincent Ambo
5512108ca7 fix(tvix/compiler): handle literal URL values
The parser creates this node type from literal URL values. Technically
these are deprecated and have been removed from nixpkgs.

Change-Id: I4d05034dd9b4d8348e4ed8a2bbb37c1b6ccef8bc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6173
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-26 17:19:51 +00:00
Vincent Ambo
7c803a7e72 feat(tvix/eval): use rustyline crate for REPL
This is a substantially nicer experience, immediately granting us
history, proper exiting and so on.

Change-Id: Iba4cb1713b9ac53d0799722bdbe2cd0e94a2f527
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6171
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-26 17:19:51 +00:00
Vincent Ambo
d14db8dcaa chore(tvix/cargo): add dirs dependency
This crate provides sensible default locations for directories on
different platforms.

Change-Id: I0b61cc7f626dc6c8df903ba0f873be24e07d69b5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6170
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-26 17:19:51 +00:00
Vincent Ambo
49f416c176 chore(tvix/cargo): add rustyline dependency
There's a few options for this, but this one seems fine in terms of
features and doesn't have an insane amount of dependencies.

Change-Id: Ief99e66bfee0ba0ba1cfdd09568b002121b7325b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6169
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-26 16:36:03 +00:00
Vincent Ambo
6c5d0344d9 style(tvix/eval): minor rephrasing in a comment
From cl/6070

Change-Id: I8ce8c1b40032d85cd2c01b04e225ae4a2842c7b7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6172
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 16:32:55 +00:00
Vincent Ambo
15c2986597 test(tvix/eval): add tests for the attrset or operator
Change-Id: I81f3ab94d8b987f5a4c87a27b2bcbb49cccee1ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6168
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 16:05:09 +00:00
Vincent Ambo
941d718a8a feat(tvix/compiler): implement or operator for attribute sets
This operator allows for accessing attribute sets (including nested
access) while also providing a default value.

This is one of the more complex operations to compile, as it needs to
keep track of a fairly large number of jumps that all need to be
patched correctly.

To make this easier to understand there's a small diagram included in
the comments.

Change-Id: Ia53bb20d8f779859bfd1692fa3f6d72af74c3a1f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6167
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 15:06:52 +00:00
Vincent Ambo
b8cec6d61e feat(tvix/vm): add opcodes for new Value::NotFound sentinel
This sentinel value is going to be used for certain nested accesses
into attribute sets.

There is a new instruction similar to `OpAttrsSelect` which leaves the
sentinel on the stack if a key is not found, instead of raising an
error.

Additionally, a new jump instruction makes its jump operation
conditional on finding such a sentinel value.

Change-Id: I2642f0a0bcc85bbe0ead68ea09a7dd794dbedeac
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6166
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 15:06:52 +00:00
Vincent Ambo
999b9c7a13 refactor(tvix/value): replace static representation with SmolStr
The only uses of the static variant were for `"name"` and `"value"`,
which are both small enough to fit into a SmolStr. The size of
NixString accomodates `String` anyways, so we may as well inline them.

Additionally smol_str is already in the dependency graph because rnix
uses it, and using it for representations of identifiers is sensible.

Change-Id: I9969312256d1657d69128e54c47dc7294a18ce58
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6165
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 15:06:52 +00:00
Vincent Ambo
f331874aeb chore(tvix/eval): implement improved Display for internal values
Having these visible more explicitly is useful while debugging.

Change-Id: I86b497883063d32792b635eb4514b7aeae484af4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6164
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 15:06:52 +00:00
Vincent Ambo
dd8f5f1dc8 feat(tvix/eval): implement nested '?' operator
Implements the nested presence check operator for attribuet sets by
traversing the chain of lookups through instructions that push/pop
sequentially deeper attribute sets onto the stack.

Note that this commit introduces a bug in case of nested attributes
not being found, which is fixed in a later commit.

Change-Id: Ic8b4c8648736f6cb048e3aa52592e4d075bf0544
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6163
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 15:06:52 +00:00
Vincent Ambo
cf3e3b784b feat(tvix/eval): implement ? operator (single-level only)
This makes it possible to check things like `{} ? a` with a single
level of nesting.

Change-Id: I567c36fcfd2f9e2f60071acd3ebfe56dea59b26f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6161
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-26 09:02:38 +00:00
Vincent Ambo
e8c4e26b41 feat(tvix/compiler): handle dynamic nodes for attribute access
Dynamic nodes (essentially unquoted interpolation) simply need to be
unwrapped (and, hopefully, evaluate to a string).

Example: `let key = "a"; in { a = 1; }.${key}`
Change-Id: Idafd376e19d0e237151b7b6c26d97713beae5041
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6160
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 09:02:38 +00:00
Vincent Ambo
5eb523e882 fix(tvix/compiler): support identifier literals in select expression
With this change, attribute set access is working as intended.

Change-Id: Ic5dbbd68aa59156106069289e7375a696909f78b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6159
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 09:02:38 +00:00
Vincent Ambo
20f5ccefeb feat(tvix/eval): implement attribute set access operator
Fairly straightforward, handling the optimised representations
manually and otherwise delegating to BTreeMap.

Note that parsing of raw identifiers is not yet implemented.

Encountering an identifier node usually means that there is locals
access going on, so we need a special case for compiling a node in
such a way that an identifier's literal value ends up on the stack.

Change-Id: I13fbab7ac657b17ef3f4c5859fe737c321890c8a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6158
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 09:02:38 +00:00
Vincent Ambo
671915837a fix(tvix/eval): add operation to assert boolean type
This operation is required because both sides of the logical operators
are strictly evaluated by Nix, even if the resulting value is not used
further.

For example, in our implementation of `&&`, if the left-hand side is
`true`, then the result of the expression is simply the right-hand
side value. This value must be asserted to be a boolean for the
semantics of the language to work correctly.

Change-Id: I34f5364f2a444753fa1d8b0a1a2b2d9cdf7c6700
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6157
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-26 09:02:38 +00:00
Griffin Smith
0c4c307926 feat(tvix/eval): Add initial benchmarking infrastructure
Bootstrap some (initially very simple, mostly proof-of-concept)
benchmarking infrastructure using Criterion, using the newly-exposed lib
from tvix-eval.

Change-Id: I4bb93c142ba8d018d7e67e58ac8907a0429398a5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6156
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: grfn <grfn@gws.fyi>
2022-08-25 16:03:55 +00:00
Griffin Smith
f648cec78e feat(tvix/eval): Expose interpret + related types from lib
Add a new `lib.rs` to tvix/eval, which `pub use`s the `interpret`
function, and all types mentioned in its return type, and then uses
*this* instead of direct `mod` statements in the `main.rs` to implement
the entrypoints to the interpreter. This is in preparation for calling
these functions from integrated benchmarking infrastructure using
Criterion, though other things (like integration tests) might want to do
that as well.

Change-Id: I7b585134a96b1c56a2ac64d2036b0e51d321bd27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6155
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: grfn <grfn@gws.fyi>
2022-08-25 16:01:46 +00:00
Vincent Ambo
63a0cc83d1 feat(tvix/compiler): implement -> (implication) operator
Similar to `||`, but inverting the left-hand side.

In other words, `a -> b` is essentially rewritten as `!a || b`.

Change-Id: I8a62da65ff070b389e46048d047a54279060a97b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6152
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 16:01:14 +00:00
Vincent Ambo
c7c7ab9bd4 feat(tvix/compiler): implement || operator
Same dance as `&&` but logically inverted.

Change-Id: I213e200e3836527e9abe510f354ee7cd1f70d041
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6151
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 16:00:55 +00:00
Vincent Ambo
4b920912b8 feat(tvix/compiler): implement && operator
This logical operator is implemented in terms of jumping operations
and thus requires slightly different treatment than other binary
operators.

Change-Id: Ib3d768b70dd7e16014c9b47d770aa74eec60ae92
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6150
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 16:00:55 +00:00
Vincent Ambo
f3f8262637 docs(tvix/compiler): add a note on use of unwrap/expect for rnix
Change-Id: I62ca28285685b69d1883afcf18c6068fc2defb5d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6149
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 16:00:55 +00:00
Vincent Ambo
d9d94eb27f feat(tvix/eval): implement if/else expressions
These expressions use simple jumps to skip the correct expression
conditionally in the bytecode by advancing the instruction pointer.

Note that these expressions are already covered by a test behind the
`nix_tests` feature flag, but adding more is probably sensible.

Change-Id: Ibe0eba95d216321c883d3b6b5816e2ab6fe7eef1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6148
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 16:00:55 +00:00
Vincent Ambo
2422f2f224 refactor(tvix/value): hide internal string representation
Wraps the string representation in an additional newtype struct with a
private field in order to hide the representation from other modules.

This is done in order to avoid accidental leakage of the internals
outside of value::string.

In fact, this caught a mistake in the compiler module which was
directly constructing an internal variant.

Change-Id: If4b627d3cff7ab9cd50ca1a3ac73245d4dcf7aef
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6147
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 12:07:30 +00:00
Vincent Ambo
a0cbc78a83 refactor(tvix/value): ensure internal attrs representation is hidden
Wraps the attrs representation in an additional newtype struct with a
private field in order to hide the representation from other modules.

This is done in order to avoid accidental leakage of the internals
outside of value::attrs.

Change-Id: I68d1d02514aa0443df4c39801001a3f1f6cc5d5c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6146
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 12:07:30 +00:00
Vincent Ambo
9407af5684 refactor(tvix/eval): encapsulate list construction in value::list
Ensuring that the implementation is not leaking out of the module lets
us keep things open for optimisations (e.g. empty list or pairs
through tuples).

Change-Id: I18fd9b7740f28c55736471e16c6b4095a05dd6d0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6145
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 12:07:30 +00:00
Vincent Ambo
75a22321ce feat(tvix/eval): implement list concatenation
Change-Id: Icdf715d116371a9f139bdf95266410bf967bef25
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6144
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-25 12:07:30 +00:00
Vincent Ambo
4eafaae9e6 feat(tvix/eval): implement binary comparison operators
This is accomplished by simply delegating to the Rust implementations
of (Partial)Ord and (Partial)Eq, which are implemented for Value and
underlying wrapper types to behave like they do in Nix.

To ease the implementation overhead, a new comparison operator macro
has been added to the VM module.

Incomparable types will raise a new error variant when a comparison is
attempted, containing both supplied types. This mimics the information
carried in the error thrown by C++ Nix.

Change-Id: Ia19634d69119d40722f3ca672387bc3a80096998
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6143
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-25 12:07:30 +00:00
Vincent Ambo
5a15ee3f5d refactor(tvix/vm): simplify implementation of OpEqual
This can now fully delegate to PartialEq of Value

Change-Id: Iaa9f4ec9b8830d516d72f83a93ab2df9a6e5697c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6142
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:34:00 +00:00
Vincent Ambo
7d55b776de feat(tvix): implement not-equals (!=) operator
Change-Id: Ic259d6d0cf30553e944682a0d1d2c610df7fe5c2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6141
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-25 11:34:00 +00:00
Vincent Ambo
058e77bab2 feat(tvix/eval): implement attrset update (//) operator
The underlying implementation does a few tricks based on which pair of
attrset representations is encountered.

Particularly the effect of short-circuiting the empty cases might be
relevant in nixpkgs/NixOS, due to the use of lib.optionalAttrs.

Change-Id: I22b978b1c69af12926489a71087c6a6219c012f3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6140
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-08-25 11:34:00 +00:00
Vincent Ambo
fa2d250d1a fix(tvix/value): explicitly delegate Ord to &str representation
I assumed that `Ord` is a marker trait like `Eq`, but it actually has
a member. Without this ordering was incoherent.

Change-Id: Id37cbdf333daf748d29b85243046c7e061b1ce29
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6139
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:11:27 +00:00
Vincent Ambo
58db7e3a65 fix(tvix/value): ensure only string values of NixString are hashed
Change-Id: I1b97cf5a9e4e235fac72a507de49a8df508bcaa1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6138
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:11:27 +00:00
Vincent Ambo
fb3d024d75 feat(tvix/eval): implement string concatenation
Change-Id: If61066e59232b2bad42b5cb5f0f2d9b9c416be8b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6137
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:11:27 +00:00
Vincent Ambo
322ce36cea refactor(tvix/vm): use a macro to handle binary arithmetic operators
Instead of constructing another runtime value representing the pair on
which to perform arithmetic, implement the same logic in the shape of
a macro.

This is designed to be compatible with operators like `+` that work
both as an arithmetic operator AND as an operator on another pair of
types.

Change-Id: I1c83649ead6117f811f1fb45482d0cadf811125e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6136
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:07:16 +00:00
Vincent Ambo
8150803e77 test(tvix/eval): add some eval-okay-* tests for trivial types
Change-Id: I85ccc07e08c67abf4fcd3752c58e1702943239ac
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6135
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 11:07:16 +00:00
Vincent Ambo
522d93745c fix(tvix/value): fix display representation of floats
Nix displays a maximum of 5 digits for floating points.

Change-Id: Ifa3c0d96fa0b24e3be8f94dfebc99e602a258355
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6133
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-08-25 10:41:39 +00:00
Vincent Ambo
ad1c11b606 chore(tvix/eval): enable test runs in naersk
Change-Id: I08c3a66a3f5c98d914d17a2ad6de98b1c02e50b2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6134
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 23:18:07 +00:00
Vincent Ambo
96e9f750c5 test(tvix/eval): add identity tests for literal evaluation
Change-Id: Id3f37fbe341e15e9428ef1d579d61a514232c0e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6132
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 23:11:12 +00:00
Vincent Ambo
3671056640 fix(tvix/value): align Display representation with Nix
Displaying the optimised representation is not useful anymore.

Change-Id: Icb962ff8865ec4207c144fbcb1aae87483b0fb7c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6131
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 23:11:12 +00:00
Vincent Ambo
c75fa365cd docs(tvix/eval): add README note on running the Nix test suite
Change-Id: I792154d5fea05414f2b14367ea4087dc2a88758e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6130
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 23:11:12 +00:00
Vincent Ambo
7d5691f0e5 chore(tvix/tests): gate Nix test suite behind nix_tests feature
Once we have full coverage they should be enabled by default.

Change-Id: Iace9e1ae9a9f901a0979ad336434004b8028fe8a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6129
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 23:11:12 +00:00
Vincent Ambo
8235384d2d chore(tvix/eval): only print AST if requested
Change-Id: If32c7fd03458a27aecb8c473f2c48b12f8cb5175
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6128
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-24 21:25:41 +00:00
Vincent Ambo
5685f7c594 fix(tvix/value): add ident_str representation of strings
When printing strings as identifiers (in attribute sets), the string
should only be quoted and escaped if it contains escape characters.

Change-Id: If2bcfa1e93dc8f00be4d7a57ec1d82fc679103c3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6127
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-24 21:25:41 +00:00
Vincent Ambo
92c53fe982 feat(tvix/tests): check in Nix' language test suite
This adds scaffolding code for running the Nix language test suite.

The majority of eval-okay-* tests should eventually be runnable as-is
by Tvix, however the eval-fail-* tests might not as we intend to have
more useful error messages than upstream Nix.

Change-Id: I4f3227f0889c55e4274b804a3072850fb78dd1bd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6126
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 21:25:41 +00:00
Vincent Ambo
b28da8ad56 chore(tvix/eval): add 'test-generator' as dev-dependency
This crate makes it easy to generate test cases from files on disk,
which is used for running the Nix test suite against Tvix.

Change-Id: I60ef26484d05e723982679dd42958adf52735916
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6125
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 21:23:12 +00:00
Vincent Ambo
4c9aad17ad fix(tvix/value): add escaping logic for Nix strings
Nix strings displayed to users must be escaped the same way as they
are in C++ Nix. This adds the scaffolding for escapes, but is most
likely not yet complete.

Change-Id: Icfdcb2ac98d292c567ba894a92b6529a53e0cc17
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6124
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-24 21:23:12 +00:00
Vincent Ambo
a2b4b4a485 fix(tvix/value): implement PartialOrd/PartialEq for strings
Instead of comparing the enum variants (which does not yield useful
behaviour), compare &str representations of the string instead.

Change-Id: I5e94b5f6c91b4561e1bc7c36d586f3d23c243764
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6112
Tested-by: BuildkiteCI
Reviewed-by: eta <tvl@eta.st>
2022-08-24 18:19:52 +00:00
Vincent Ambo
6dc9ca5723 feat(tvix/value): introduce string representation with &'static str
For cases where the strings are statically known (such as the
oft-occuring name/value), this can be a useful optimisation.

It's also much more convenient in tests.

Change-Id: Ie462b684805bd4986ea5e85ca4bff663bc2d3c3c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6111
Tested-by: BuildkiteCI
Reviewed-by: eta <tvl@eta.st>
2022-08-24 18:19:52 +00:00
Vincent Ambo
c7ba2dec04 test(tvix/value): add simple attrset construction tests
These do not yet test nested attribute sets; we need to add some more
inspection primitives first.

Change-Id: Icfc99bf17c73ebefc0d882a84f0ca73ec688a54d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6110
Reviewed-by: eta <tvl@eta.st>
Tested-by: BuildkiteCI
2022-08-24 18:19:52 +00:00
Vincent Ambo
08b4d65fbd feat(tvix/value): implement nested attribute set literals
With this change, nested attribute sets can now be created from
literals.

This required some logic for dealing with cases where at a deeper
nesting point a literal attribute set was constructed from an
optimised representation.

For example, this is valid Nix code:

```nix
{
  a = {};   # creates optimised empty representation
  a.b = 1;  # wants to add a `b = 1` to it

  b = { name = "foo"; value = "bar"; }; # creates optimised K/V repr
  b.foo = 42; # wants to add an additional `foo = 42`
}
```

In these cases, the attribute set must be coerced to a map
representation first which is achieved by the new internal
NixAttr::map_mut helper.

Change-Id: Ia61d3d9d14c4e0f5e207c00f6a2f4daa3265afb2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6109
Reviewed-by: eta <tvl@eta.st>
Tested-by: BuildkiteCI
2022-08-24 18:19:52 +00:00
Vincent Ambo
293fb0ef53 refactor(tvix/value): encapsulate attrset logic within value::attrs
The internal optimisations of the set representation were previously
leaking into the VM, which is highly undesirable.

Keeping it encapsulated allows us to do additional optimisations
within value::attrs without being concerned about its use in the VM.

Change-Id: I7e7020bb0983b9d355d3db747b049b2faa60131f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6108
Reviewed-by: eta <tvl@eta.st>
Tested-by: BuildkiteCI
2022-08-24 18:19:52 +00:00
Vincent Ambo
52736a1dbc refactor(tvix/rm): introduce helper for AttrSet Entry API
There are multiple points where an insertion needs to be done into an
attribute set, but copying the key or checking for presence before
insertion should be avoided

As that is a little bit noisy, it's been factored out into a helper
function in this commit.

Change-Id: Ibcb054ebeb25a1236c06c812f47c8e74180d4fc9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6107
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-14 00:24:33 +00:00
Vincent Ambo
295d6e1d59 feat(tvix/vm): implement first nested attribute set construction
This can construct non-overlapping nested attribute sets (i.e. `{ a.b
= 1; b.c = 2; }`, but not `{ a.b = 1; a.c = 2; }`).

In order to do the latter, it's necessary to gain the ability to
manipulate the in-progress attribute set construction. There's
multiple different options for this ...

Change-Id: If1a762a720b175e8eb4216cbf96a7434d22640fb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6106
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-14 00:23:32 +00:00
Vincent Ambo
8c2bc683cd refactor(tvix/value): explicitly implement PartialEq for value
There are some notions of equality (due to e.g. different backing
variants for types, or Nix particularities) that don't work correctly
when deriving PartialEq.

Change-Id: Ide83ae67d051cc0b3ca89cefb283f17d0207acce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6105
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 20:24:12 +00:00
Vincent Ambo
e15bd9aa63 fix(tvix/eval): Fail on duplicate attribute set keys
Change-Id: I57373ca76d0e25a5d08a8dfce9d5949099326fc0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6104
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 20:24:12 +00:00
Vincent Ambo
175eb97505 feat(tvix/eval): construct internal attribute path representation
This is required for constructing nested attribute sets at runtime.

There'll be quite a lot of optimisation potential with this solution
eventually, if it should turn out to be a bottleneck.

This introduces a conceptual change, in that the `Value` enum is now
an enum representing "all runtime values" instead of "all Nix language
types". This makes sense in general, as this type will also contain
Chunk representations etc. which are not exposed to users.

Change-Id: Ic5f72b2a0965b146c6a451efad34c6a81ca1aad8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6103
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-13 20:24:12 +00:00
Vincent Ambo
ec1770f95a feat(tvix/vm): implement construction of optimised KV attrsets
For name/value pairs (which occur extremely often in Nix and make up a
significant chunk of the runtime cost of evaluating nixpkgs) we
substitute an optimised representation.

For now this will only be used if the name/value pair keys were
specified as literal identifiers or strings (i.e. if chunks are
encountered as keys they are not forced and a normal attribute set
backed by a map will be constructed).

Change-Id: Ic79746c323e627528bd58b1a6024ee8d0aff7858
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6102
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-13 20:24:12 +00:00
Vincent Ambo
e876c3a41c fix(tvix/value): KV struct needs to carry name as Value, too
Users may construct a pair that falls into the name/value optimisation
but where `name` is not actually a string, as from the language
perspective there is nothing special about this attribute set.

We also can not conditionally apply this by forcing the key at this
point, as this would change the language semantics.

Therefore, the name in the optimised representation is also carried as
`Value`.

Change-Id: I5be8a4c98ba19ebdfb7203a929f714a04492512e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6101
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-08-13 20:24:12 +00:00
Vincent Ambo
2dcbbb8c4a feat(tvix/value): implement Display properly for lists
Change-Id: I991d235cf52fbd42eb839b384f9c55ee64fa86c4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6100
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 18:28:36 +00:00
Vincent Ambo
56caaf70ca fix(tvix/errors): display a useful intermediate error representation
Change-Id: If979a2aa21444320427f54e6530a55cab873856b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6099
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 18:28:36 +00:00
Vincent Ambo
a93933b487 feat(tvix): implement string interpolation
This adds a new instruction which assembles an interpolated string
from a specified number of fragments, which are already going to be
located on the stack in the right position.

This will raise a type error if any of the fragments do not evaluate
to a string.

Change-Id: I5756248fa3e9fcc3d063c14db40b332f7e20a588
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6098
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 18:28:36 +00:00
Vincent Ambo
3577841bde feat(tvix/compiler): compile non-interpolated string literals
This sets up the scaffolding for compiling interpolation, but those
instructions do not yet exist.

Change-Id: Ife41bbbf432d9661abe566c92437409dd0da44e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6097
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 18:28:36 +00:00
Vincent Ambo
72863d81fc style(tvix/eval): display Display representation of runtime values
Change-Id: Ifbe05c2da9493c9e132a2d2e94a451d6091542a5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6096
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 18:28:36 +00:00
Vincent Ambo
910336c68c feat(tvix/compiler): compile list literals
Change-Id: I2c6fedc3dbb7d449d700f3972c3fbd4a7d147f6c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6095
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-13 15:39:26 +00:00
Vincent Ambo
5763b62172 feat(tvix/vm): implement list construction
Change-Id: Iec2b4910800ab29daae6d71b58a8acd14ccb1cc1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6094
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-13 15:35:24 +00:00
Vincent Ambo
c67747cbe1 feat(tvix/value): add runtime representation of simple lists
There might be more logic in the future to encapsulate different
backing implementations of lists as well.

Change-Id: Ib7064fab48bf88b0c8913b0ecfa2108177c7c9fd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6093
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-13 15:35:24 +00:00
Vincent Ambo
6f13c16f28 docs(tvix/eval): add design documentation for attrset opcodes
Change-Id: I303b57e035543f4597c6247983d1d533e4014638
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6092
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 15:31:50 +00:00
Vincent Ambo
57a723aaa9 feat(tvix/eval): implement trivial attribute set literals
Implements attribute set literals without nesting. Technically this
already supports dynamic key fragments (evaluating to strings), though
the only way to create these (interpolation) is not yet implemented.

However, creating simple attribute sets like `{ }`, or `{ a = 15; }`
or `{ a = 10 * 2; }` works.

Recursive attribute sets are not yet implemented as we do not have any
kind of scope access yet anyways.

This is implemented using a new instruction that creates an attribute
set with a given number of elements by popping key/value pairs off the
stack.

Change-Id: I0f9aac7a131a112d3f66b131297686b38aaeddf2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6091
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 15:31:50 +00:00
Vincent Ambo
e24248df3b feat(tvix/value): add some necessary helpers for strings
Deriving Ord/Eq is required for the ordered BTreeMaps. Once interning
is implemented this will require some extra magic for the sort order,
but that's fine.

Change-Id: I0c654648eb3609a4a01d84868c25f43a4d35bc2e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6089
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 11:50:37 +00:00
Vincent Ambo
865717a8db fix(tvix/eval): print code even if runtime fails
Change-Id: I357c9adf939cb6001afa73ad02282d94ee22d0ba
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6088
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 11:50:37 +00:00
Vincent Ambo
2ed38a7cdb feat(tvix/eval): add Value variants for strings & attrsets
Change-Id: Idebf663ab7fde3955aae50f635320f7eb6c353e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6087
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 11:50:37 +00:00
Vincent Ambo
ba03226e51 feat(tvix/eval): add module for attribute set implementations
Change-Id: I6002bd5e5596b93325dea6c862370ba5235c0f08
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6086
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 11:50:37 +00:00
Vincent Ambo
d26c097d1b feat(tvix/eval): add module for string type implementation
Change-Id: I5e4465acc4a676c10d7374b14f7a09240202b466
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6085
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-13 11:50:37 +00:00
Vincent Ambo
3ed45caad1 feat(tvix/eval): implement Display trait for Value enum
This representation should match what the Nix REPL shows for result
values.

Change-Id: If3143d969fcdc123a6029e2aeb7bbd6ae51aeb71
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6082
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 14:12:07 +00:00
Vincent Ambo
0d2896519c refactor(tvix/eval): move NumberPair struct definition to vm module
This isn't relevant to the value type itself.

Change-Id: I678bc92a8a530b1081ed498bf3ff7925217bcc01
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6081
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 14:09:27 +00:00
Vincent Ambo
9c5a249b30 feat(tvix/compiler): incompletely handle true/false/null literals
These are a bit tricky to implement because Nix technically treats
them as identifiers, and only if the identifier is not explicitly
overridden within the scope does it yield the expected literal values.

Note that weirdness even occurs with scopedImport.

Change-Id: Ie55723405ccfcc25da37c5a08fa3332f37cf9ae5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6080
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 14:09:27 +00:00
Vincent Ambo
d431f43f5f feat(tvix/eval): implement boolean inversion operator
Change-Id: Icb1d449fdee4d67b5f1eefdbc01baa1584ea0a67
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6079
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 14:09:27 +00:00
Vincent Ambo
ded0fb9e21 feat(tvix/eval): implement equality operator
Change-Id: I9dd54aed72cd7e67593dc76f5a046ebbda40c26f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6078
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 14:09:27 +00:00
Vincent Ambo
28f57abac1 refactor(tvix/compiler): use rnix's typed AST for literal values
Change-Id: Ic56ab64ad82343c7cdf8168ef41ee0a97f7e1dd9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6077
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:24:10 +00:00
Vincent Ambo
18fe188c3e feat(tvix/compiler): implement parens precedence
Change-Id: I8944354b3690d7504e4fe4254f14be5b849b9bcf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6076
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:24:10 +00:00
Vincent Ambo
72be759e1e feat(tvix/eval): implement unary negation operator
Change-Id: I5d012cc073e55d79d7b34b88283aab3164864293
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6075
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:24:10 +00:00
Vincent Ambo
d35ecc0caf feat(tvix/eval): implement simple arithmetic binary operations
Implements simple arithmetic operations (+, -, *, /).

There is some scaffolding included to pop and coerce pairs of numbers,
as the Nix language will let arithmetic operators apply to arbitrary
pairs of number types (always resulting in floats if the types are
mixed).

Change-Id: I5f62c363bdea8baa6ef812cc64c5406759d257cf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6074
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:24:10 +00:00
Vincent Ambo
e96a2934ad feat(tvix/eval): add error variant for runtime type errors
Change-Id: I74155cf01766b7a991a69522945bff67fbca5a16
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6073
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:24:10 +00:00
Vincent Ambo
e8253c7044 chore(tvix/eval): wire things up for development flow
This creates a REPL which outputs compiled bytecode, constants, and VM
results for code snippets.

Change-Id: If63f79a961456afd6a4cdf59b994107ff7ab8b47
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6072
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
2022-08-12 13:05:28 +00:00
Vincent Ambo
d59968649e feat(tvix/eval): add initial stack-based VM
This can't do anything other than compute a single literal, for now

Change-Id: Ia28f9da51c906b590a198e77a4ca5d45a871106b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6071
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:05:16 +00:00
Vincent Ambo
34df2c8473 feat(tvix/eval): add initial barebones compiler
This compiler can only take care of very trivial literals so far.

Change-Id: I9dfac75a801b7235f868061a979ae24159fe1425
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6070
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:05:16 +00:00
Vincent Ambo
3aaefc3000 feat(tvix/eval): add initial chunk representation
Change-Id: I53202e93938bede421c8f1c98901e4c67544e257
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6069
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:05:16 +00:00
Vincent Ambo
48a7449834 feat(tvix/eval): add initial opcode representation
Change-Id: Ibc7685a6b0b92e08f0b6c82cf7d9b04fbb593a4e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6068
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 13:05:16 +00:00
Vincent Ambo
8b7d2fd59e feat(tvix/eval): add initial value representation
Change-Id: I427a04e89994662df2750dffe21991bad48aab15
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6066
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:39:19 +00:00
Vincent Ambo
bef8d67b6c chore(tvix/eval): add rnix-parser dependency
Change-Id: I81bd8416b3837a728ecd7911fe1ca06e89b9e90e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6065
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:39:19 +00:00
Vincent Ambo
8921688334 chore(tvix/eval): bootstrap some evaluator boilerplate
Change-Id: I7770a20948d18a8506c2418dea21202aa21a6ddc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6064
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:39:19 +00:00
Vincent Ambo
a9b2157fba chore(tvix/eval): check in naersk-based default.nix
Change-Id: I9ff0c4a196747361a3e421863beaff07a4972b0f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6067
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:39:19 +00:00
Vincent Ambo
7be4581876 docs(tvix/eval): Add initial evaluator README
Change-Id: I85df002dc13c91a184d064586244f6a7440320fb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6063
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:34:29 +00:00
Vincent Ambo
d1bf3d3577 feat(tvix/eval): check in generated project skeleton
Change-Id: Iecc8283abb289de71f22076fd88892f6ded99cb3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6062
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-08-12 12:34:29 +00:00