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.
* 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>`
* Add source-env test for dynamic path
* Use correct module ID for env overlay imports
* Remove parser check from "overlay list"
It would cause unnecessary errors from some inner scope if some
overlay module was also defined in some inner scope.
* Restore Cargo.lock back
* Remove comments
* Allow private imports inside modules
Can call `use ...` inside modules now.
* Add more tests
* Add a leak test
* Refactor exportables; Prepare for 'export use'
* Fix description
* Implement 'export use' command
This allows re-exporting module's commands and aliases from another
module.
* Add more tests; Fix import pattern list strings
The import pattern strings didn't trim the surrounding quotes.
* Add ignored test
* expand durations to include month, year, decade
* remove commented out fn
* oops, found more debug comments
* tweaked tests for the new way, borrowed heavily from chrono-humanize-rs
* clippy
* grammar
* Fix 5978
* Add unit test for explicit glob
* Format
* Expansion vs none-expansion
* Add unit tests
* Fix format..
* Add debug message for MacOS
* Fix UT on Mac and add tests for windows
* cleanup
* clean up windows test
* single and double qoutes tests
* format...
* Save format.
* Add log to failed windows unit tests
* try `touch` a file
* PS or CMD
* roll back some change
* format
* Remove log and test case
* Add unit test comments
* Fix
Co-authored-by: Frank <v-frankz@microsoft.com>
* adds `capture-errors` flag for `do`
* adds `get-type` core command to get type
* fmt
* add tests in example
* fmt
* fix tests
* manually revert previous changes related to `get-type`
* adds method to check for error name using `into string`
* fix clippy
* attempts to add `div` math operator
* allows `//` to be used too
* fmt:
* clippy issue
* returns appropriate type
* returns appropriate type 2
* fmt
* ensure consistency; rename to `fdiv`
* Update parser.rs
* 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
* fix argument type
* while run external, convert list argument to str
* fix argument converting logic
* using parse_list_expression instead of parse_full_cell_path
* make parsing logic more explicit
* revert changes
* add tests
* a more helpful error for let in pipeline
* a more helpful error for let in pipeline fmt
* changed help message
* type-o
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
Schema `0o[77]` with the same padding behavior as the other binary literals
- this updates #5551
- test for parsing binary from octal
- test for string parsing
* 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>
* Initial implementation of ordered call args
* Run cargo fmt
* Fix some clippy lints
* Add positional len and nth
* Cargo fmt
* Remove more old nth calls
* Good ole rustfmt
* Add named len
Co-authored-by: Hristo Filaretov <h.filaretov@protonmail.com>
