# 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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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
> ```
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# After Submitting
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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 $x`
closes#9634
# User-Facing Changes
`mut` now joins `let` in being able to be assigned from a pipeline
# Tests + Formatting
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you're using the standard code style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-std/tests/run.nu` to run the tests for the
standard library
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> toolkit check pr
> ```
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# After Submitting
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# Description
This changes the default behaviour of `let` to be able to take a
pipeline as its initial value.
For example:
```
> let x = "hello world" | str length
```
This is a change from the existing behaviour, where the right hand side
is assumed to be an expression. Pipelines are more general, and can be
more powerful.
My google foo is failing me, but this also fixes this issue:
```
let x = foo
```
Currently, this reads `foo` as a bareword that gets converted to a
string rather than running the `foo` command. In practice, this is
really annoying and is a really hard to spot bug in a script.
# User-Facing Changes
BREAKING CHANGE BREAKING CHANGE
`let` gains the power to be assigned via a pipeline. However, this
changes the behaviour of `let x = foo` from assigning the string "foo"
to `$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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clippy::needless_collect -A clippy::result_large_err` to check that
you're using the standard code style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-std/tests/run.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
> ```
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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.
