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# Description
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The [nushell/demo](https://github.com/nushell/demo) project successfully
demonstrated running Nushell in the browser using WASM. However, the
current version of Nushell cannot be easily built for the
`wasm32-unknown-unknown` target, the default for `wasm-bindgen`.
This PR introduces initial support for the `wasm32-unknown-unknown`
target by disabling OS-dependent features such as filesystem access, IO,
and platform/system-specific functionality. This separation is achieved
using a new `os` feature in the following crates:
- `nu-cmd-lang`
- `nu-command`
- `nu-engine`
- `nu-protocol`
The `os` feature includes all functionality that interacts with an
operating system. It is enabled by default, but can be disabled using
`--no-default-features`. All crates that depend on these core crates now
use `--no-default-features` to allow compilation for WASM.
To demonstrate compatibility, the following script builds all crates
expected to work with WASM. Direct user interaction, running external
commands, working with plugins, and features requiring `openssl` are out
of scope for now due to their complexity or reliance on C libraries,
which are difficult to compile and link in a WASM environment.
```nushell
[ # compatible crates
"nu-cmd-base",
"nu-cmd-extra",
"nu-cmd-lang",
"nu-color-config",
"nu-command",
"nu-derive-value",
"nu-engine",
"nu-glob",
"nu-json",
"nu-parser",
"nu-path",
"nu-pretty-hex",
"nu-protocol",
"nu-std",
"nu-system",
"nu-table",
"nu-term-grid",
"nu-utils",
"nuon"
] | each {cargo build -p $in --target wasm32-unknown-unknown --no-default-features}
```
## Caveats
This PR has a few caveats:
1. **`miette` and `terminal-size` Dependency Issue**
`miette` depends on `terminal-size`, which uses `rustix` when the target
is not Windows. However, `rustix` requires `std::os::unix`, which is
unavailable in WASM. To address this, I opened a
[PR](https://github.com/eminence/terminal-size/pull/68) for
`terminal-size` to conditionally compile `rustix` only when the target
is Unix. For now, the `Cargo.toml` includes patches to:
- Use my forked version of `terminal-size`.
- ~~Use an unreleased version of `miette` that depends on
`terminal-size@0.4`.~~
These patches are temporary and can be removed once the upstream changes
are merged and released.
2. **Test Output Adjustments**
Due to the slight bump in the `miette` version, one test required
adjustments to accommodate minor formatting changes in the error output,
such as shifted newlines.
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
This shouldn't break anything but allows using some crates for targeting
`wasm32-unknown-unknown` to revive the demo page eventually.
# Tests + Formatting
<!--
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
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- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used` to
check that you're using the standard code style
- `cargo test --workspace` to check that all tests pass (on Windows make
sure to [enable developer
mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use toolkit.nu; toolkit test stdlib"` to run the
tests for the standard library
> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
I did not add any extra tests, I just checked that compiling works, also
when using the host target but unselecting the `os` feature.
# After Submitting
<!-- If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
-->
~~Breaking the wasm support can be easily done by adding some `use`s or
by adding a new dependency, we should definitely add some CI that also
at least builds against wasm to make sure that building for it keep
working.~~
I added a job to build wasm.
---------
Co-authored-by: Ian Manske <ian.manske@pm.me>
# Description
This PR closes#14137 and allows the display hook to be set on byte
streams. So, with a hook like this below.
```nushell
display_output: {
metadata access {|meta| match $meta.content_type? {
"application/x-nuscript" | "application/x-nuon" | "text/x-nushell" => { nu-highlight },
"application/json" => { ^bat --language=json --color=always --style=plain --paging=never },
_ => {},
}
} | table
}
```
You could type `open toolkit.nu` and the text of toolkit.nu would be
highlighted by nu-highlight. This PR also changes the way content-type
is assigned with `open`. Previously it would only assign it if `--raw`
was specified.
Lastly, it changes the `is_external()` function to only say
`ByteStreamSource::Child`'s are external instead of both Child and
`ByteStreamSource::File`. Again, this was to allow the hook to function
properly. I'm not sure what negative ramifications changing
`is_external()` could have, but there may be some?
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
# Tests + Formatting
<!--
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used` to
check that you're using the standard code style
- `cargo test --workspace` to check that all tests pass (on Windows make
sure to [enable developer
mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use toolkit.nu; toolkit test stdlib"` to run the
tests for the standard library
> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->
# After Submitting
<!-- If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
-->
# Description
Fixes#13991. This was done by more clearly separating the case when a
pipeline is drained vs when it is being written (to a file).
I also added an `OutDest::Print` case which might not be strictly
necessary, but is a helpful addition.
# User-Facing Changes
Bug fix.
# Tests + Formatting
Added a test.
# After Submitting
There are still a few redirection bugs that I found, but they require
larger code changes, so I'll leave them until after the release.
# Description
Partialy addresses #13868. `try` does not catch non-zero exit code
errors from the last command in a pipeline if the result is assigned to
a variable using `let` (or `mut`).
This was fixed by adding a new `OutDest::Value` case. This is used when
the pipeline is in a "value" position. I.e., it will be collected into a
value. This ended up replacing most of the usages of `OutDest::Capture`.
So, this PR also renames `OutDest::Capture` to `OutDest::PipeSeparate`
to better fit the few remaining use cases for it.
# User-Facing Changes
Bug fix.
# Tests + Formatting
Added two tests.
# Description
This PR makes it so that non-zero exit codes and termination by signal
are treated as a normal `ShellError`. Currently, these are silent
errors. That is, if an external command fails, then it's code block is
aborted, but the parent block can sometimes continue execution. E.g.,
see #8569 and this example:
```nushell
[1 2] | each { ^false }
```
Before this would give:
```
╭───┬──╮
│ 0 │ │
│ 1 │ │
╰───┴──╯
```
Now, this shows an error:
```
Error: nu:🐚:eval_block_with_input
× Eval block failed with pipeline input
╭─[entry #1:1:2]
1 │ [1 2] | each { ^false }
· ┬
· ╰── source value
╰────
Error: nu:🐚:non_zero_exit_code
× External command had a non-zero exit code
╭─[entry #1:1:17]
1 │ [1 2] | each { ^false }
· ──┬──
· ╰── exited with code 1
╰────
```
This PR fixes#12874, fixes#5960, fixes#10856, and fixes#5347. This
PR also partially addresses #10633 and #10624 (only the last command of
a pipeline is currently checked). It looks like #8569 is already fixed,
but this PR will make sure it is definitely fixed (fixes#8569).
# User-Facing Changes
- Non-zero exit codes and termination by signal now cause an error to be
thrown.
- The error record value passed to a `catch` block may now have an
`exit_code` column containing the integer exit code if the error was due
to an external command.
- Adds new config values, `display_errors.exit_code` and
`display_errors.termination_signal`, which determine whether an error
message should be printed in the respective error cases. For
non-interactive sessions, these are set to `true`, and for interactive
sessions `display_errors.exit_code` is false (via the default config).
# Tests
Added a few tests.
# After Submitting
- Update docs and book.
- Future work:
- Error if other external commands besides the last in a pipeline exit
with a non-zero exit code. Then, deprecate `do -c` since this will be
the default behavior everywhere.
- Add a better mechanism for exit codes and deprecate
`$env.LAST_EXIT_CODE` (it's buggy).
# Description
Add `README.md` files to each crate in our workspace (-plugins) and also
include it in the `lib.rs` documentation for <docs.rs> (if there is no
existing `lib.rs` crate documentation)
In all new README I added the defensive comment that the crates are not
considered stable for public consumption. If necessary we can adjust
this if we deem a crate useful for plugin authors.
# Description
This PR adds an internal representation language to Nushell, offering an
alternative evaluator based on simple instructions, stream-containing
registers, and indexed control flow. The number of registers required is
determined statically at compile-time, and the fixed size required is
allocated upon entering the block.
Each instruction is associated with a span, which makes going backwards
from IR instructions to source code very easy.
Motivations for IR:
1. **Performance.** By simplifying the evaluation path and making it
more cache-friendly and branch predictor-friendly, code that does a lot
of computation in Nushell itself can be sped up a decent bit. Because
the IR is fairly easy to reason about, we can also implement
optimization passes in the future to eliminate and simplify code.
2. **Correctness.** The instructions mostly have very simple and
easily-specified behavior, so hopefully engine changes are a little bit
easier to reason about, and they can be specified in a more formal way
at some point. I have made an effort to document each of the
instructions in the docs for the enum itself in a reasonably specific
way. Some of the errors that would have happened during evaluation
before are now moved to the compilation step instead, because they don't
make sense to check during evaluation.
3. **As an intermediate target.** This is a good step for us to bring
the [`new-nu-parser`](https://github.com/nushell/new-nu-parser) in at
some point, as code generated from new AST can be directly compared to
code generated from old AST. If the IR code is functionally equivalent,
it will behave the exact same way.
4. **Debugging.** With a little bit more work, we can probably give
control over advancing the virtual machine that `IrBlock`s run on to
some sort of external driver, making things like breakpoints and single
stepping possible. Tools like `view ir` and [`explore
ir`](https://github.com/devyn/nu_plugin_explore_ir) make it easier than
before to see what exactly is going on with your Nushell code.
The goal is to eventually replace the AST evaluator entirely, once we're
sure it's working just as well. You can help dogfood this by running
Nushell with `$env.NU_USE_IR` set to some value. The environment
variable is checked when Nushell starts, so config runs with IR, or it
can also be set on a line at the REPL to change it dynamically. It is
also checked when running `do` in case within a script you want to just
run a specific piece of code with or without IR.
# Example
```nushell
view ir { |data|
mut sum = 0
for n in $data {
$sum += $n
}
$sum
}
```
```gas
# 3 registers, 19 instructions, 0 bytes of data
0: load-literal %0, int(0)
1: store-variable var 904, %0 # let
2: drain %0
3: drop %0
4: load-variable %1, var 903
5: iterate %0, %1, end 15 # for, label(1), from(14:)
6: store-variable var 905, %0
7: load-variable %0, var 904
8: load-variable %2, var 905
9: binary-op %0, Math(Plus), %2
10: span %0
11: store-variable var 904, %0
12: load-literal %0, nothing
13: drain %0
14: jump 5
15: drop %0 # label(0), from(5:)
16: drain %0
17: load-variable %0, var 904
18: return %0
```
# Benchmarks
All benchmarks run on a base model Mac Mini M1.
## Iterative Fibonacci sequence
This is about as best case as possible, making use of the much faster
control flow. Most code will not experience a speed improvement nearly
this large.
```nushell
def fib [n: int] {
mut a = 0
mut b = 1
for _ in 2..=$n {
let c = $a + $b
$a = $b
$b = $c
}
$b
}
use std bench
bench { 0..50 | each { |n| fib $n } }
```
IR disabled:
```
╭───────┬─────────────────╮
│ mean │ 1ms 924µs 665ns │
│ min │ 1ms 700µs 83ns │
│ max │ 3ms 450µs 125ns │
│ std │ 395µs 759ns │
│ times │ [list 50 items] │
╰───────┴─────────────────╯
```
IR enabled:
```
╭───────┬─────────────────╮
│ mean │ 452µs 820ns │
│ min │ 427µs 417ns │
│ max │ 540µs 167ns │
│ std │ 17µs 158ns │
│ times │ [list 50 items] │
╰───────┴─────────────────╯
```
##
[gradient_benchmark_no_check.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/gradient_benchmark_no_check.nu)
IR disabled:
```
╭───┬──────────────────╮
│ 0 │ 27ms 929µs 958ns │
│ 1 │ 21ms 153µs 459ns │
│ 2 │ 18ms 639µs 666ns │
│ 3 │ 19ms 554µs 583ns │
│ 4 │ 13ms 383µs 375ns │
│ 5 │ 11ms 328µs 208ns │
│ 6 │ 5ms 659µs 542ns │
╰───┴──────────────────╯
```
IR enabled:
```
╭───┬──────────────────╮
│ 0 │ 22ms 662µs │
│ 1 │ 17ms 221µs 792ns │
│ 2 │ 14ms 786µs 708ns │
│ 3 │ 13ms 876µs 834ns │
│ 4 │ 13ms 52µs 875ns │
│ 5 │ 11ms 269µs 666ns │
│ 6 │ 6ms 942µs 500ns │
╰───┴──────────────────╯
```
##
[random-bytes.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/random-bytes.nu)
I got pretty random results out of this benchmark so I decided not to
include it. Not clear why.
# User-Facing Changes
- IR compilation errors may appear even if the user isn't evaluating
with IR.
- IR evaluation can be enabled by setting the `NU_USE_IR` environment
variable to any value.
- New command `view ir` pretty-prints the IR for a block, and `view ir
--json` can be piped into an external tool like [`explore
ir`](https://github.com/devyn/nu_plugin_explore_ir).
# Tests + Formatting
All tests are passing with `NU_USE_IR=1`, and I've added some more eval
tests to compare the results for some very core operations. I will
probably want to add some more so we don't have to always check
`NU_USE_IR=1 toolkit test --workspace` on a regular basis.
# After Submitting
- [ ] release notes
- [ ] further documentation of instructions?
- [ ] post-release: publish `nu_plugin_explore_ir`
# Description
This PR introduces a new `Signals` struct to replace our adhoc passing
around of `ctrlc: Option<Arc<AtomicBool>>`. Doing so has a few benefits:
- We can better enforce when/where resetting or triggering an interrupt
is allowed.
- Consolidates `nu_utils::ctrl_c::was_pressed` and other ad-hoc
re-implementations into a single place: `Signals::check`.
- This allows us to add other types of signals later if we want. E.g.,
exiting or suspension.
- Similarly, we can more easily change the underlying implementation if
we need to in the future.
- Places that used to have a `ctrlc` of `None` now use
`Signals::empty()`, so we can double check these usages for correctness
in the future.
# Description
Currently, this pipeline doesn't work `open --raw file | take 100`,
since the type of the byte stream is `Unknown`, but `take` expects
`Binary` streams. This PR changes commands that expect
`ByteStreamType::Binary` to also work with `ByteStreamType::Unknown`.
This was done by adding two new methods to `ByteStreamType`:
`is_binary_coercible` and `is_string_coercible`. These return true if
the type is `Unknown` or matches the type in the method name.
# Description
This PR allows byte streams to optionally be colored as being
specifically binary or string data, which guarantees that they'll be
converted to `Binary` or `String` appropriately on `into_value()`,
making them compatible with `Type` guarantees. This makes them
significantly more broadly usable for command input and output.
There is still an `Unknown` type for byte streams coming from external
commands, which uses the same behavior as we previously did where it's a
string if it's UTF-8.
A small number of commands were updated to take advantage of this, just
to prove the point. I will be adding more after this merges.
# User-Facing Changes
- New types in `describe`: `string (stream)`, `binary (stream)`
- These commands now return a stream if their input was a stream:
- `into binary`
- `into string`
- `bytes collect`
- `str join`
- `first` (binary)
- `last` (binary)
- `take` (binary)
- `skip` (binary)
- Streams that are explicitly binary colored will print as a streaming
hexdump
- example:
```nushell
1.. | each { into binary } | bytes collect
```
# Tests + Formatting
I've added some tests to cover it at a basic level, and it doesn't break
anything existing, but I do think more would be nice. Some of those will
come when I modify more commands to stream.
# After Submitting
There are a few things I'm not quite satisfied with:
- **String trimming behavior.** We automatically trim newlines from
streams from external commands, but I don't think we should do this with
internal commands. If I call a command that happens to turn my string
into a stream, I don't want the newline to suddenly disappear. I changed
this to specifically do it only on `Child` and `File`, but I don't know
if this is quite right, and maybe we should bring back the old flag for
`trim_end_newline`
- **Known binary always resulting in a hexdump.** It would be nice to
have a `print --raw`, so that we can put binary data on stdout
explicitly if we want to. This PR doesn't change how external commands
work though - they still dump straight to stdout.
Otherwise, here's the normal checklist:
- [ ] release notes
- [ ] docs update for plugin protocol changes (added `type` field)
---------
Co-authored-by: Ian Manske <ian.manske@pm.me>
# Description
This PR introduces a `ByteStream` type which is a `Read`-able stream of
bytes. Internally, it has an enum over three different byte stream
sources:
```rust
pub enum ByteStreamSource {
Read(Box<dyn Read + Send + 'static>),
File(File),
Child(ChildProcess),
}
```
This is in comparison to the current `RawStream` type, which is an
`Iterator<Item = Vec<u8>>` and has to allocate for each read chunk.
Currently, `PipelineData::ExternalStream` serves a weird dual role where
it is either external command output or a wrapper around `RawStream`.
`ByteStream` makes this distinction more clear (via `ByteStreamSource`)
and replaces `PipelineData::ExternalStream` in this PR:
```rust
pub enum PipelineData {
Empty,
Value(Value, Option<PipelineMetadata>),
ListStream(ListStream, Option<PipelineMetadata>),
ByteStream(ByteStream, Option<PipelineMetadata>),
}
```
The PR is relatively large, but a decent amount of it is just repetitive
changes.
This PR fixes#7017, fixes#10763, and fixes#12369.
This PR also improves performance when piping external commands. Nushell
should, in most cases, have competitive pipeline throughput compared to,
e.g., bash.
| Command | Before (MB/s) | After (MB/s) | Bash (MB/s) |
| -------------------------------------------------- | -------------:|
------------:| -----------:|
| `throughput \| rg 'x'` | 3059 | 3744 | 3739 |
| `throughput \| nu --testbin relay o> /dev/null` | 3508 | 8087 | 8136 |
# User-Facing Changes
- This is a breaking change for the plugin communication protocol,
because the `ExternalStreamInfo` was replaced with `ByteStreamInfo`.
Plugins now only have to deal with a single input stream, as opposed to
the previous three streams: stdout, stderr, and exit code.
- The output of `describe` has been changed for external/byte streams.
- Temporary breaking change: `bytes starts-with` no longer works with
byte streams. This is to keep the PR smaller, and `bytes ends-with`
already does not work on byte streams.
- If a process core dumped, then instead of having a `Value::Error` in
the `exit_code` column of the output returned from `complete`, it now is
a `Value::Int` with the negation of the signal number.
# After Submitting
- Update docs and book as necessary
- Release notes (e.g., plugin protocol changes)
- Adapt/convert commands to work with byte streams (high priority is
`str length`, `bytes starts-with`, and maybe `bytes ends-with`).
- Refactor the `tee` code, Devyn has already done some work on this.
---------
Co-authored-by: Devyn Cairns <devyn.cairns@gmail.com>
