# Description
Close: #12083Close: #12084
# User-Facing Changes
It's a breaking change because we have switched the position of
`<initial>` and `<closure>`, after the change, initial value will be
optional. So it's possible to do something like this:
```nushell
> let f = {|fib = [0, 1]| {out: $fib.0, next: [$fib.1, ($fib.0 + $fib.1)]} }
> generate $f | first 5
╭───┬───╮
│ 0 │ 0 │
│ 1 │ 1 │
│ 2 │ 1 │
│ 3 │ 2 │
│ 4 │ 3 │
╰───┴───╯
```
It will also raise error if user don't give initial value, and the
closure don't have default parameter.
```nushell
❯ let f = {|fib| {out: $fib.0, next: [$fib.1, ($fib.0 + $fib.1)]} }
❯ generate $f
Error: × The initial value is missing
╭─[entry #5:1:1]
1 │ generate $f
· ────┬───
· ╰── Missing intial value
╰────
help: Provide <initial> value in generate, or assigning default value to closure parameter
```
# Tests + Formatting
Added some test cases.
---------
Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>
# 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.
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This PR should close#13247
# Description
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- The deprecated `itertools::unfold` function is replaced with
`std::iter::from_fn` for the generate command.
- The mutable iterator state is no longer passed as an argument to
`from_fn` but it gets captured with the closure's `move`.
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
No user facing changes
# Tests + Formatting
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Tests for the generate command are passing locally.
# After Submitting
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---------
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
# Description
Removes `list<any>` as an input type for the `generate` command. This
command does not accept pipeline input (and cannot, logically). This can
be seen by the use of `_input` in the command's `run()`.
Also, due to #13199, in order to pass `toolkit check pr`, one of the
examples was changed to remove the `result`. This is probably a better
demonstration of the ability of the command to infinitely generate a
list anyway, and an infinite list can't be represented in a `result`.
# User-Facing Changes
Should only be a change to the help. The input type was never valid and
couldn't have been used.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# 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>
# Description
Does some misc changes to `ListStream`:
- Moves it into its own module/file separate from `RawStream`.
- `ListStream`s now have an associated `Span`.
- This required changes to `ListStreamInfo` in `nu-plugin`. Note sure if
this is a breaking change for the plugin protocol.
- Hides the internals of `ListStream` but also adds a few more methods.
- This includes two functions to more easily alter a stream (these take
a `ListStream` and return a `ListStream` instead of having to go through
the whole `into_pipeline_data(..)` route).
- `map`: takes a `FnMut(Value) -> Value`
- `modify`: takes a function to modify the inner stream.
# Description
Adds two new types in `nu-engine` for evaluating closures: `ClosureEval`
and `ClosureEvalOnce`. This removed some duplicate code and centralizes
our logic for setting up, running, and cleaning up closures. For
example, in the future if we are able to reduce the cloning necessary to
run a closure, then we only have to change the code related to these
types.
`ClosureEval` and `ClosureEvalOnce` are designed with a builder API.
`ClosureEval` is used to run a closure multiple times whereas
`ClosureEvalOnce` is used for a one-shot closure.
# User-Facing Changes
Should be none, unless I messed up one of the command migrations.
Actually, this will fix any unreported environment bugs for commands
that didn't reset the env after running a closure.
# Description
This adds a `SharedCow` type as a transparent copy-on-write pointer that
clones to unique on mutate.
As an initial test, the `Record` within `Value::Record` is shared.
There are some pretty big wins for performance. I'll post benchmark
results in a comment. The biggest winner is nested access, as that would
have cloned the records for each cell path follow before and it doesn't
have to anymore.
The reusability of the `SharedCow` type is nice and I think it could be
used to clean up the previous work I did with `Arc` in `EngineState`.
It's meant to be a mostly transparent clone-on-write that just clones on
`.to_mut()` or `.into_owned()` if there are actually multiple
references, but avoids cloning if the reference is unique.
# User-Facing Changes
- `Value::Record` field is a different type (plugin authors)
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] use for `EngineState`
- [ ] use for `Value::List`
# Description
When implementing a `Command`, one must also import all the types
present in the function signatures for `Command`. This makes it so that
we often import the same set of types in each command implementation
file. E.g., something like this:
```rust
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
ShellError, Signature, Span, Type, Value,
};
```
This PR adds the `nu_engine::command_prelude` module which contains the
necessary and commonly used types to implement a `Command`:
```rust
// command_prelude.rs
pub use crate::CallExt;
pub use nu_protocol::{
ast::{Call, CellPath},
engine::{Command, EngineState, Stack},
record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned,
PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
```
This should reduce the boilerplate needed to implement a command and
also gives us a place to track the breadth of the `Command` API. I tried
to be conservative with what went into the prelude modules, since it
might be hard/annoying to remove items from the prelude in the future.
Let me know if something should be included or excluded.
# Description
The PR overhauls how IO redirection is handled, allowing more explicit
and fine-grain control over `stdout` and `stderr` output as well as more
efficient IO and piping.
To summarize the changes in this PR:
- Added a new `IoStream` type to indicate the intended destination for a
pipeline element's `stdout` and `stderr`.
- The `stdout` and `stderr` `IoStream`s are stored in the `Stack` and to
avoid adding 6 additional arguments to every eval function and
`Command::run`. The `stdout` and `stderr` streams can be temporarily
overwritten through functions on `Stack` and these functions will return
a guard that restores the original `stdout` and `stderr` when dropped.
- In the AST, redirections are now directly part of a `PipelineElement`
as a `Option<Redirection>` field instead of having multiple different
`PipelineElement` enum variants for each kind of redirection. This
required changes to the parser, mainly in `lite_parser.rs`.
- `Command`s can also set a `IoStream` override/redirection which will
apply to the previous command in the pipeline. This is used, for
example, in `ignore` to allow the previous external command to have its
stdout redirected to `Stdio::null()` at spawn time. In contrast, the
current implementation has to create an os pipe and manually consume the
output on nushell's side. File and pipe redirections (`o>`, `e>`, `e>|`,
etc.) have precedence over overrides from commands.
This PR improves piping and IO speed, partially addressing #10763. Using
the `throughput` command from that issue, this PR gives the following
speedup on my setup for the commands below:
| Command | Before (MB/s) | After (MB/s) | Bash (MB/s) |
| --------------------------- | -------------:| ------------:|
-----------:|
| `throughput o> /dev/null` | 1169 | 52938 | 54305 |
| `throughput \| ignore` | 840 | 55438 | N/A |
| `throughput \| null` | Error | 53617 | N/A |
| `throughput \| rg 'x'` | 1165 | 3049 | 3736 |
| `(throughput) \| rg 'x'` | 810 | 3085 | 3815 |
(Numbers above are the median samples for throughput)
This PR also paves the way to refactor our `ExternalStream` handling in
the various commands. For example, this PR already fixes the following
code:
```nushell
^sh -c 'echo -n "hello "; sleep 0; echo "world"' | find "hello world"
```
This returns an empty list on 0.90.1 and returns a highlighted "hello
world" on this PR.
Since the `stdout` and `stderr` `IoStream`s are available to commands
when they are run, then this unlocks the potential for more convenient
behavior. E.g., the `find` command can disable its ansi highlighting if
it detects that the output `IoStream` is not the terminal. Knowing the
output streams will also allow background job output to be redirected
more easily and efficiently.
# User-Facing Changes
- External commands returned from closures will be collected (in most
cases):
```nushell
1..2 | each {|_| nu -c "print a" }
```
This gives `["a", "a"]` on this PR, whereas this used to print "a\na\n"
and then return an empty list.
```nushell
1..2 | each {|_| nu -c "print -e a" }
```
This gives `["", ""]` and prints "a\na\n" to stderr, whereas this used
to return an empty list and print "a\na\n" to stderr.
- Trailing new lines are always trimmed for external commands when
piping into internal commands or collecting it as a value. (Failure to
decode the output as utf-8 will keep the trailing newline for the last
binary value.) In the current nushell version, the following three code
snippets differ only in parenthesis placement, but they all also have
different outputs:
1. `1..2 | each { ^echo a }`
```
a
a
╭────────────╮
│ empty list │
╰────────────╯
```
2. `1..2 | each { (^echo a) }`
```
╭───┬───╮
│ 0 │ a │
│ 1 │ a │
╰───┴───╯
```
3. `1..2 | (each { ^echo a })`
```
╭───┬───╮
│ 0 │ a │
│ │ │
│ 1 │ a │
│ │ │
╰───┴───╯
```
But in this PR, the above snippets will all have the same output:
```
╭───┬───╮
│ 0 │ a │
│ 1 │ a │
╰───┴───╯
```
- All existing flags on `run-external` are now deprecated.
- File redirections now apply to all commands inside a code block:
```nushell
(nu -c "print -e a"; nu -c "print -e b") e> test.out
```
This gives "a\nb\n" in `test.out` and prints nothing. The same result
would happen when printing to stdout and using a `o>` file redirection.
- External command output will (almost) never be ignored, and ignoring
output must be explicit now:
```nushell
(^echo a; ^echo b)
```
This prints "a\nb\n", whereas this used to print only "b\n". This only
applies to external commands; values and internal commands not in return
position will not print anything (e.g., `(echo a; echo b)` still only
prints "b").
- `complete` now always captures stderr (`do` is not necessary).
# After Submitting
The language guide and other documentation will need to be updated.
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# Description
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This PR adds a new evaluator path with callbacks to a mutable trait
object implementing a Debugger trait. The trait object can do anything,
e.g., profiling, code coverage, step debugging. Currently,
entering/leaving a block and a pipeline element is marked with
callbacks, but more callbacks can be added as necessary. Not all
callbacks need to be used by all debuggers; unused ones are simply empty
calls. A simple profiler is implemented as a proof of concept.
The debugging support is implementing by making `eval_xxx()` functions
generic depending on whether we're debugging or not. This has zero
computational overhead, but makes the binary slightly larger (see
benchmarks below). `eval_xxx()` variants called from commands (like
`eval_block_with_early_return()` in `each`) are chosen with a dynamic
dispatch for two reasons: to not grow the binary size due to duplicating
the code of many commands, and for the fact that it isn't possible
because it would make Command trait objects object-unsafe.
In the future, I hope it will be possible to allow plugin callbacks such
that users would be able to implement their profiler plugins instead of
having to recompile Nushell.
[DAP](https://microsoft.github.io/debug-adapter-protocol/) would also be
interesting to explore.
Try `help debug profile`.
## Screenshots
Basic output:

To profile with more granularity, increase the profiler depth (you'll
see that repeated `is-windows` calls take a large chunk of total time,
making it a good candidate for optimizing):

## Benchmarks
### Binary size
Binary size increase vs. main: **+40360 bytes**. _(Both built with
`--release --features=extra,dataframe`.)_
### Time
```nushell
# bench_debug.nu
use std bench
let test = {
1..100
| each {
ls | each {|row| $row.name | str length }
}
| flatten
| math avg
}
print 'debug:'
let res2 = bench { debug profile $test } --pretty
print $res2
```
```nushell
# bench_nodebug.nu
use std bench
let test = {
1..100
| each {
ls | each {|row| $row.name | str length }
}
| flatten
| math avg
}
print 'no debug:'
let res1 = bench { do $test } --pretty
print $res1
```
`cargo run --release -- bench_debug.nu` is consistently 1--2 ms slower
than `cargo run --release -- bench_nodebug.nu` due to the collection
overhead + gathering the report. This is expected. When gathering more
stuff, the overhead is obviously higher.
`cargo run --release -- bench_nodebug.nu` vs. `nu bench_nodebug.nu` I
didn't measure any difference. Both benchmarks report times between 97
and 103 ms randomly, without one being consistently higher than the
other. This suggests that at least in this particular case, when not
running any debugger, there is no runtime overhead.
## API changes
This PR adds a generic parameter to all `eval_xxx` functions that forces
you to specify whether you use the debugger. You can resolve it in two
ways:
* Use a provided helper that will figure it out for you. If you wanted
to use `eval_block(&engine_state, ...)`, call `let eval_block =
get_eval_block(&engine_state); eval_block(&engine_state, ...)`
* If you know you're in an evaluation path that doesn't need debugger
support, call `eval_block::<WithoutDebug>(&engine_state, ...)` (this is
the case of hooks, for example).
I tried to add more explanation in the docstring of `debugger_trait.rs`.
## TODO
- [x] Better profiler output to reduce spam of iterative commands like
`each`
- [x] Resolve `TODO: DEBUG` comments
- [x] Resolve unwraps
- [x] Add doc comments
- [x] Add usage and extra usage for `debug profile`, explaining all
columns
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
Hopefully none.
# Tests + Formatting
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Make sure you've run and fixed any issues with these commands:
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- `cargo test --workspace` to check that all tests pass (on Windows make
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mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
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crates/nu-std"` 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
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# Description
This updates all the positional arguments (except with
`--features=dataframe` or `--features=extra`) to start with an uppercase
letter and end with a period.
Part of #5066, specifically [this
comment](/nushell/nushell/issues/5066#issuecomment-1421528910)
Some arguments had example data removed from them because it also
appears in the examples.
There are other inconsistencies in positional arguments I noticed while
making the tests pass which I will bring up in #5066.
# User-Facing Changes
Positional arguments are now consistent
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
Automatic documentation updates
# Description
Replace `.to_string()` used in `GenericError` with `.into()` as
`.into()` seems more popular
Replace `Vec::new()` used in `GenericError` with `vec![]` as `vec![]`
seems more popular
(There are so, so many)
# Description
Add an extension trait `IgnoreCaseExt` to nu_utils which adds some case
insensitivity helpers, and use them throughout nu to improve the
handling of case insensitivity. Proper case folding is done via unicase,
which is already a dependency via mime_guess from nu-command.
In actuality a lot of code still does `to_lowercase`, because unicase
only provides immediate comparison and doesn't expose a `to_folded_case`
yet. And since we do a lot of `contains`/`starts_with`/`ends_with`, it's
not sufficient to just have `eq_ignore_case`. But if we get access in
the future, this makes us ready to use it with a change in one place.
Plus, it's clearer what the purpose is at the call site to call
`to_folded_case` instead of `to_lowercase` if it's exclusively for the
purpose of case insensitive comparison, even if it just does
`to_lowercase` still.
# User-Facing Changes
- Some commands that were supposed to be case insensitive remained only
insensitive to ASCII case (a-z), and now are case insensitive w.r.t.
non-ASCII characters as well.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
---------
Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>
# Description
Changes the `captures` field in `Closure` from a `HashMap` to a `Vec`
and makes `Stack::captures_to_stack` take an owned `Vec` instead of a
borrowed `HashMap`.
This eliminates the conversion to a `Vec` inside `captures_to_stack` and
makes it possible to avoid clones altogether when using an owned
`Closure` (which is the case for most commands). Additionally, using a
`Vec` reduces the size of `Value` by 8 bytes (down to 72).
# User-Facing Changes
Breaking API change for `nu-protocol`.
# Description
This PR renames the `unfold` command to `generate`.
closes#10760
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
# Tests + Formatting
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Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
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- `cargo test --workspace` to check that all tests pass (on Windows make
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mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use std testing; testing run-tests --path
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> **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
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