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.
* Fix ignore-errors for select
* fix Value::List match
* fix invalid rows
* add tests
* fix ListStream match
* add one more test for ListStream
* add more tests
* tweak words
* fix: fixcd
try to fix
Log: try to fix the bug with can enter a permisson error fold
* change wording
* fat
* fmt
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
* make format filesize more flexible
* make code simpler
* finish refactor on bytes commands
* finish refactor on str commands
* fimplify code
* rename from column_paths to cell_paths
* fix: ✨ "saner" default for mv
fixes#6747
As highlighted in the issue, the default behavior of nu currently
is to overwrite the destination file without notice.
This is not a "standard" expectation users that want this behavior
can create a dedicated alias.
* fix: 📝 edit the comment
* fix: ✨ updated the tests
* fix: 🚧 use --force for case test
* Remove unnecessary `#[allow]` annots
Reduce the number of lint exceptions that are not necessary with the
current state of the code (or more recent toolchain)
* Remove dead code from `FileStructure` in nu-command
* Replace `allow(unused)` with relevant feature switch
* Deal with `needless_collect` with annotations
* Change hack for needless_collect in `from json`
This change obviates the need for `allow(needless_collect)`
Removes a pessimistic allocation for empty strings, but increases
allocation size to `Value`
Probably not really worth it.
* Revert "Deal with `needless_collect` with annotations"
This reverts commit 05aca98445.
The previous state seems to better from a performance perspective as a
`Vec<String>` is lighter weight than `Vec<Value>`
* Filter out empty glob patterns
An empty argument to the "glob" command will now produce an empty result.
Working towards nushell/nushell#6653.
* Run `cargo fmt --all`
Just autoformatted the repo so that CI passes and we have a consistent code
format across modules.
* Treat empty glob argument as error
The glob command will now report an empty string argument as an error instead
of silently ignoring it.
See https://github.com/nushell/nushell/pull/6707#discussion_r993345013.
* Add tests for glob command
Two small tests for the glob command, one to check that the empty string errors
it, and another to sanity check the '*' glob, have been added.
* Rename glob sanity check star test
Co-authored-by: Kyle Anderson <kyle.anderson@uwaterloo.ca>
* remove export_env command
* remove several export env usage in test code
* adjust hiding relative test case
* fix clippy
* adjust tests
* update tests
* unignore these tests to expose ut failed
* using `use` instead of `overlay use` in some tests
* Revert "using `use` instead of `overlay use` in some tests"
This reverts commit 2ae24b24c3.
* Revert "adjust hiding relative test case"
This reverts commit 4369af6d05.
* Bring back module example
* Revert "update tests"
This reverts commit 6ae94ef513.
* Fix tests
* "Fix" a test
* Remove remaining deprecated env functionality
* Re-enable environment hiding for `hide`
To not break virtualenv since the overlay update is not merged yet
* Fix hiding env in `hide` and ignore some tests
Co-authored-by: kubouch <kubouch@gmail.com>
