# 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.
# Description
Both `Block` and `Pipeline` had `Index`/`IndexMut` implementations to
access their elements, that are currently unused.
Explicit helpers or iteration would generally be preferred anyways but
in the current state the inner containers are `pub` and are liberally
used. (Sometimes with potentially panicking indexing or also iteration)
As it is potentially unclear what the meaning of the element from a
block or pipeline queried by a usize is, let's remove it entirely until
we come up with a better API.
# User-Facing Changes
None
Plugin authors shouldn't dig into AST internals
# Description
This is a pretty heavy refactor of the parser to support multiple parser
errors. It has a few issues we should address before landing:
- [x] In some cases, error quality has gotten worse `1 / "bob"` for
example
- [x] if/else isn't currently parsing correctly
- probably others
# User-Facing Changes
This may have error quality degradation as we adjust to the new error
reporting mechanism.
# 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 -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-utils/standard_library/tests.nu` 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
Added a few syntax errors in ints and strings, changed parser to stop
and show that error rather than continue trying to parse those tokens as
some other shape. However, I don't see how to push this direction much
further, and most of the classic confusing errors can't be changed.
Flagged as WIP for the moment, but passes all checks and works better
than current release:
1. I have yet to figure out how to make these errors refer back to the
book, as I see some other errors do.
2. How to give syntax error when malformed int is first token in line?
Currently parsed as external command, user gets confusing error message.
3. Would like to be more strict with *decimal* int literals (lacking,
e.g, `0x' prefix). Need to tinker more with the order of parse shape
calls, currently, float is tried after int, so '1.4' has to be passed.
_(Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.)_
```bash
〉"\z"
Error:
╭─[entry #3:1:1]
1 │ "\z"
· ─┬─
· ╰── Syntax error in string, unrecognized character after escape '\'.
╰────
```
Canonic presentation of a syntax error.
```bash
〉" \u{01ffbogus}"
Error:
× Invalid syntax
╭─[entry #2:1:1]
1 │ " \u{01ffbogus}"
· ───────┬──────
· ╰── Syntax error in string, expecting 1 to 6 hex digits in unicode escape '\u{X...}', max value 10FFFF.
╰────
```
Malformed unicode escape in string, flagged as error.
String parse can be opinionated, it's the last shape tried.
```bash
〉0x22bogus
Error: nu:🐚:external_command (link)
× External command failed
╭─[entry #4:1:1]
1 │ 0x22bogus
· ────┬────
· ╰── executable was not found
╰────
help: No such file or directory (os error 2)
```
A *correct* number in first token would be evaluated, but an *incorrect*
one is treated as external command? Confusing to users.
```bash
〉0 + 0x22bogus
Error:
× Invalid syntax
╭─[entry #5:1:1]
1 │ 0 + 0x22bogus
· ────┬────
· ╰── Syntax error in int, invalid digits in radix 16 int.
╰────
```
Can give syntax error if token is unambiguously int literal. e.g has 0b
or 0x prefix, could not be a float.
```bash
〉0 + 098bogus
Error: nu::parser::unsupported_operation (link)
× Types mismatched for operation.
╭─[entry #6:1:1]
1 │ 0 + 098bogus
· ┬ ┬ ────┬───
· │ │ ╰── string
· │ ╰── doesn't support these values.
· ╰── int
╰────
help: Change int or string to be the right types and try again.
```
But *decimal* literal (no prefix) can't be too strict. Parser is going
to try float later. So '1.4' must be passed.
# User-Facing Changes
First and foremost, more specific error messages for typos in string and
int literals. Probably improves interactive user experience.
But a script that was causing and then checking for specific error might
notice a different error message.
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
# Tests + Formatting
Added (positive and negative unit tests in `cargo test -p nu-parser`.
Didn't add integration tests.
Make sure you've run and fixed any issues with these commands:
- [x] `cargo fmt --all -- --check` to check standard code formatting
(`cargo fmt --all` applies these changes)
- [x] `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- [x] `cargo test --workspace` to check that all tests pass
# 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.
---------
Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>
# Description
Lint: `clippy::uninlined_format_args`
More readable in most situations.
(May be slightly confusing for modifier format strings
https://doc.rust-lang.org/std/fmt/index.html#formatting-parameters)
Alternative to #7865
# User-Facing Changes
None intended
# Tests + Formatting
(Ran `cargo +stable clippy --fix --workspace -- -A clippy::all -D
clippy::uninlined_format_args` to achieve this. Depends on Rust `1.67`)
# Description
Support extended unicode escapes in strings with same syntax as Rust:
`"\u{6e}"`.
# User-Facing Changes
New syntax in string literals, `\u{NNNNNN}`, to go along with the
existing `\uNNNN`.
New syntax accepts 1-6 hex digits and rejects values greater than
0x10FFFF (max Unicode char)..
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
Won't break existing scripts, since this is new syntax.
We might consider deprecating `char -u`, since users can now embed
unicode chars > 0xFFFF with the new escape.
# Tests + Formatting
Several unit tests and one integration test added.
- [x] `cargo fmt --all -- --check` to check standard code formatting
(`cargo fmt --all` applies these changes)
Done
- [x] `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
Done
- [x] `cargo test --workspace` to check that all tests pass
Done
# 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.
