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.
- Custom commands are true for builtin and custom
- Add classification as external command
- Specify wildcard in keyword: keyword is true for builtin and keyword
* Revert "Revert "Try again: in unix like system, set foreground process while running external command (#6273)" (#6542)"
This reverts commit 2bb367f570.
* Make foreground job control hopefully work correctly
These changes are mostly inspired by the glibc manual.
* Fix typo in external command description
* Only restore tty control to shell when no fg procs are left; reuse pgrp
* Rework terminal acquirement code to be like fish
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
* 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>
* Remove comment
* Split delta and environment merging
* Move table mode to a more logical place
* Cleanup
* Merge environment after reading default_env.nu
* Fmt
* input and output tests
* input and output types for dfr
* expression converter
* remove deprecated command
* correct expressions
* cargo clippy
* identifier for ls
* cargo clippy
* type for head and tail expression
* modify full cell path if block
* Allow env vars to be kept from removed overlay
* Rename --keep to --keep-custom; Add new test
* Rename some symbols
* (WIP) Start working on --keep for defs and aliases
* Fix decls/aliases not melting properly
* Use id instead of the whole cloned overlay
* Rewrite overlay remove for no reason
Doesn't fix the bug but at least looks better.
* Rename variable
* Fix adding overlay env vars
* Add more tests; Fmt + Clippy
* WIP: Start laying overlays
* Rename Overlay->Module; Start adding overlay
* Revamp adding overlay
* Add overlay add tests; Disable debug print
* Fix overlay add; Add overlay remove
* Add overlay remove tests
* Add missing overlay remove file
* Add overlay list command
* (WIP?) Enable overlays for env vars
* Move OverlayFrames to ScopeFrames
* (WIP) Move everything to overlays only
ScopeFrame contains nothing but overlays now
* Fix predecls
* Fix wrong overlay id translation and aliases
* Fix broken env lookup logic
* Remove TODOs
* Add overlay add + remove for environment
* Add a few overlay tests; Fix overlay add name
* Some cleanup; Fix overlay add/remove names
* Clippy
* Fmt
* Remove walls of comments
* List overlays from stack; Add debugging flag
Currently, the engine state ordering is somehow broken.
* Fix (?) overlay list test
* Fix tests on Windows
* Fix activated overlay ordering
* Check for active overlays equality in overlay list
This removes the -p flag: Either both parser and engine will have the
same overlays, or the command will fail.
* Add merging on overlay remove
* Change help message and comment
* Add some remove-merge/discard tests
* (WIP) Track removed overlays properly
* Clippy; Fmt
* Fix getting last overlay; Fix predecls in overlays
* Remove merging; Fix re-add overwriting stuff
Also some error message tweaks.
* Fix overlay error in the engine
* Update variable_completions.rs
* Adds flags and optional arguments to view-source (#5446)
* added flags and optional arguments to view-source
* removed redundant code
* removed redundant code
* fmt
* fix bug in shell_integration (#5450)
* fix bug in shell_integration
* add some comments
* enable cd to work with directory abbreviations (#5452)
* enable cd to work with abbreviations
* add abbreviation example
* fix tests
* make it configurable
* make cd recornize symblic link (#5454)
* implement seq char command to generate single character sequence (#5453)
* add tmp code
* add seq char command
* Add split number flag in `split row` (#5434)
Signed-off-by: Yuheng Su <gipsyh.icu@gmail.com>
* Add two more overlay tests
* Add ModuleId to OverlayFrame
* Fix env conversion accidentally activating overlay
It activated overlay from permanent state prematurely which would
cause `overlay add` to misbehave.
* Remove unused parameter; Add overlay list test
* Remove added traces
* Add overlay commands examples
* Modify TODO
* Fix $nu.scope iteration
* Disallow removing default overlay
* Refactor some parser errors
* Remove last overlay if no argument
* Diversify overlay examples
* Make it possible to update overlay's module
In case the origin module updates, the overlay add loads the new module,
makes it overlay's origin and applies the changes. Before, it was
impossible to update the overlay if the module changed.
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
Co-authored-by: pwygab <88221256+merelymyself@users.noreply.github.com>
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
Co-authored-by: WindSoilder <WindSoilder@outlook.com>
Co-authored-by: Yuheng Su <gipsyh.icu@gmail.com>
* Pass completion options to each fetch() call
* Add MatchAlgorithm to CompletionOptions
* Add unit test for MatchAlgorithm
* Pass completion options to directory completer
* Add search terms to command
* Rename Signature desc to usage
To be named uniformly with extra_usage
* Throw in foldl search term for reduce
* Add missing usage to post
* Add search terms to signature
* Try to add capnp Signature serialization
* Fix alias import
Alias importing was registering the alias id as a decl instead of alias.
This caused issues when hiding and then reimporting the alias.
* Clippy format
Co-authored-by: Hristo Filaretov <h.filaretov@protonmail.com>
