# Description
This makes assignment operations and `const` behave the same way `let`
and `mut` do, absorbing the rest of the pipeline.
Changes the lexer to be able to recognize assignment operators as a
separate token, and then makes the lite parser continue to push spans
into the same command regardless of any redirections or pipes if an
assignment operator is encountered. Because the pipeline is no longer
split up by the lite parser at this point, it's trivial to just parse
the right hand side as if it were a subexpression not contained within
parentheses.
# User-Facing Changes
Big breaking change. These are all now possible:
```nushell
const path = 'a' | path join 'b'
mut x = 2
$x = random int
$x = [1 2 3] | math sum
$env.FOO = random chars
```
In the past, these would have led to (an attempt at) bare word string
parsing. So while `$env.FOO = bar` would have previously set the
environment variable `FOO` to the string `"bar"`, it now tries to run
the command named `bar`, hence the major breaking change.
However, this is desirable because it is very consistent - if you see
the `=`, you can just assume it absorbs everything else to the right of
it.
# Tests + Formatting
Added tests for the new behaviour. Adjusted some existing tests that
depended on the right hand side of assignments being parsed as
barewords.
# After Submitting
- [ ] release notes (breaking change!)
# Description
This PR adds raw string support by using `r#` at the beginning of single
quoted strings and `#` at the end.
Notice that escapes do not process, even within single quotes,
parentheses don't mean anything, $variables don't mean anything. It's
just a string.
```nushell
❯ echo r#'one\ntwo (blah) ($var)'#
one\ntwo (blah) ($var)
```
Notice how they work without `echo` or `print` and how they work without
carriage returns.
```nushell
❯ r#'adsfa'#
adsfa
❯ r##"asdfa'@qpejq'##
asdfa'@qpejq
❯ r#'asdfasdfasf
∙ foqwejfqo@'23rfjqf'#
```
They also have a special configurable color in the repl. (use single
quotes though)
They should work like rust raw literals and allow `r##`, `r###`,
`r####`, etc, to help with having one or many `#`'s in the middle of
your raw-string.
They should work with `let` as well.
```nushell
r#'some\nraw\nstring'# | str upcase
```
closes https://github.com/nushell/nushell/issues/5091
# 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:
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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
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> ```
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# After Submitting
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---------
Co-authored-by: WindSoilder <WindSoilder@outlook.com>
Co-authored-by: Ian Manske <ian.manske@pm.me>
# Description
Work for #7149
- **Error `with-env` given uneven count in list form**
- **Fix `with-env` `CantConvert` to record**
- **Error `with-env` when given protected env vars**
- **Deprecate list/table input of vars to `with-env`**
- **Remove examples for deprecated input**
# User-Facing Changes
## Deprecation of the following forms
```
> with-env [MYENV "my env value"] { $env.MYENV }
my env value
> with-env [X Y W Z] { $env.X }
Y
> with-env [[X W]; [Y Z]] { $env.W }
Z
```
## recommended standardized form
```
# Set by key-value record
> with-env {X: "Y", W: "Z"} { [$env.X $env.W] }
╭───┬───╮
│ 0 │ Y │
│ 1 │ Z │
╰───┴───╯
```
## (Side effect) Repeated definitions in an env shorthand are now
disallowed
```
> FOO=bar FOO=baz $env
Error: nu:🐚:column_defined_twice
× Record field or table column used twice: FOO
╭─[entry #1:1:1]
1 │ FOO=bar FOO=baz $env
· ─┬─ ─┬─
· │ ╰── field redefined here
· ╰── field first defined here
╰────
```
# 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
As title, currently on latest main, nushell confused user if it allows
implicit casting between glob and string:
```nushell
let x = "*.txt"
def glob-test [g: glob] { open $g }
glob-test $x
```
It always expand the glob although `$x` is defined as a string.
This pr implements a solution from @kubouch :
> We could make it really strict and disallow all autocasting between
globs and strings because that's what's causing the "magic" confusion.
Then, modify all builtins that accept globs to accept oneof(glob,
string) and the rules would be that globs always expand and strings
never expand
# User-Facing Changes
After this pr, user needs to use `into glob` to invoke `glob-test`, if
user pass a string variable:
```nushell
let x = "*.txt"
def glob-test [g: glob] { open $g }
glob-test ($x | into glob)
```
Or else nushell will return an error.
```
3 │ glob-test $x
· ─┬
· ╰── can't convert string to glob
```
# Tests + Formatting
Done
# After Submitting
Nan
# Description
Close: #9673Close: #8277Close: #10944
This pr introduces the following syntax:
1. `e>|`, pipe stderr to next command. Example: `$env.FOO=bar nu
--testbin echo_env_stderr FOO e>| str length`
2. `o+e>|` and `e+o>|`, pipe both stdout and stderr to next command,
example: `$env.FOO=bar nu --testbin echo_env_mixed out-err FOO FOO e+o>|
str length`
Note: it only works for external commands. ~There is no different for
internal commands, that is, the following three commands do the same
things:~ Edit: it raises errors if we want to pipes for internal
commands
```
❯ ls e>| str length
Error: × `e>|` only works with external streams
╭─[entry #1:1:1]
1 │ ls e>| str length
· ─┬─
· ╰── `e>|` only works on external streams
╰────
❯ ls e+o>| str length
Error: × `o+e>|` only works with external streams
╭─[entry #2:1:1]
1 │ ls e+o>| str length
· ──┬──
· ╰── `o+e>|` only works on external streams
╰────
```
This can help us to avoid some strange issues like the following:
`$env.FOO=bar (nu --testbin echo_env_stderr FOO) e>| str length`
Which is hard to understand and hard to explain to users.
# User-Facing Changes
Nan
# Tests + Formatting
To be done
# After Submitting
Maybe update documentation about these syntax.
# Description
Fixes a bug in `let` where the pipeline wasn't being properly
redirected.
fixes#9767
# User-Facing Changes
Shouldn't have any breaking changes, as this should be better for
expected use cases.
# 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
sure to [enable developer
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**
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> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->
# After Submitting
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documentation](https://github.com/nushell/nushell.github.io) after the
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# Description
This extends the syntax fix for `let` (#9589) to `mut` as well.
Example: `mut x = "hello world" | str length; print $x`
closes#9634
# User-Facing Changes
`mut` now joins `let` in being able to be assigned from a pipeline
# Tests + Formatting
<!--
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Make sure you've run and fixed any issues with these commands:
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clippy::needless_collect -A clippy::result_large_err` to check that
you're using the standard code style
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- `cargo run -- crates/nu-std/tests/run.nu` to run the tests for the
standard library
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> ```
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# After Submitting
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# Description
This changes the default behaviour of `let` to be able to take a
pipeline as its initial value.
For example:
```
> let x = "hello world" | str length
```
This is a change from the existing behaviour, where the right hand side
is assumed to be an expression. Pipelines are more general, and can be
more powerful.
My google foo is failing me, but this also fixes this issue:
```
let x = foo
```
Currently, this reads `foo` as a bareword that gets converted to a
string rather than running the `foo` command. In practice, this is
really annoying and is a really hard to spot bug in a script.
# User-Facing Changes
BREAKING CHANGE BREAKING CHANGE
`let` gains the power to be assigned via a pipeline. However, this
changes the behaviour of `let x = foo` from assigning the string "foo"
to `$x` to being "run the command `foo` and give the result to `$x`"
# 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
- `cargo run -- crates/nu-std/tests/run.nu` to run the tests for the
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> ```
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# After Submitting
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# Description
this pr condenses `MutBuiltinVar`, `LetBuiltinVar` and `ConstBuiltinVar`
into one error:
```nu
Error: nu::parser::name_is_builtin_var
× `in` used as variable name.
╭─[entry #69:1:1]
1 │ let in = 420
· ─┬
· ╰── already a builtin variable
╰────
help: 'in' is the name of a builtin Nushell variable and cannot be used
as a variable name
```
it also fixes this case which was previously not handled
```nu
let $nu = 420 # this variable would have been 'lost'
```
# Description
Fixes: #8136
# User-Facing Changes
The following command
```
let VAR = ^cat non-existing-file; echo "failed"
```
will no longer output `failed` message
# 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
# 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: Reilly Wood <reilly.wood@icloud.com>
This adds support for (limited) mutable variables. Mutable variables are created with mut much the same way immutable variables are made with let.
Mutable variables allow mutation via the assignment operator (=).
❯ mut x = 100
❯ $x = 200
❯ print $x
200
Mutable variables are limited in that they're only tended to be used in the local code block. Trying to capture a local variable will result in an error:
❯ mut x = 123; {|| $x }
Error: nu::parser::expected_keyword (link)
× Capture of mutable variable.
The intent of this limitation is to reduce some of the issues with mutable variables in general: namely they make code that's harder to reason about. By reducing the scope that a mutable variable can be used it, we can help create local reasoning about them.
Mutation can occur with fields as well, as in this case:
❯ mut y = {abc: 123}
❯ $y.abc = 456
❯ $y
On a historical note: mutable variables are something that we resisted for quite a long time, leaning as much as we could on the functional style of pipelines and dataflow. That said, we've watched folks struggle to work with reduce as an approximation for patterns that would be trivial to express with local mutation. With that in mind, we're leaning towards the happy path.
