This restores a basic version of the `post` command.
Some source types have been omitted from this first take.
I copied from `fetch` and from `post`@0.40.0.
Part of #4356
* Add `date format --list`, and make format string optional (providing default)
* Make DRY
`into datetime --list` now uses `generate_strfttime_list` from `date format --list`
* refactor strftime to use current datetime
* Fix formatting of specification descriptions
Fixes issues caused when copying directly from docs.rs
* Change default format to rfc2822
Perhaps to make it more DRY, functions from `into datetime` can be used. However, currently `into datetime` is a bit tricky to use as it needs a separate time zone argument.
* Tweak in-shell docs to match modified behavior
* Show %#z format specifier in `into datetime --list` only
* cargo fmt
* Satisfy clippy
* Add different features combinations
* Specify styles manually
* Fix args
* Fix typo
* Let other CI jobs finish if one fails
* Fix unused symbols without plugin feature
* Put "which" tests behind "which" feature
* Add Python virtualenv job
* Oops forgot git command
* Install Nushell in virtualenv tests
* Add names to steps; Test v.env in separate step
* cd into virtualenv
* Do not run on Python 2.7
* Build Nushell after formatting and clippy checks
* Add alias interning
Now, AliasId is used to reference aliases stored in EngineState, similar
to decls, blocks, etc.
* Fix wrong message
* Fix using decl instead of alias
* Extend also alias id visibility
* Merge also aliases from delta
* Add alias hiding code
Does not work yet but passes tests at least.
* Fix wrong alias lookup and visibility appending
* Add hide alias tests
* Fmt & Clippy
* Fix random clippy warnings in "which" command
* Fix "index out of bounds" when input to group-by is empty #4369
* Fix formatting #4369
* Adds test for empty input
Co-authored-by: Ray Henry <ray.henry@thermofisher.com>
Same rationale as in #4378
Also accelerate `grid`
before:
```
Command being timed: "./eager_nu -c for i in 0..100000 { echo whatever } | grid"
User time (seconds): 0.21
System time (seconds): 0.05
Percent of CPU this job got: 36%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.71
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 48112
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 10580
Voluntary context switches: 266
Involuntary context switches: 2595
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
```
after:
```
Command being timed: "./lazy_nu -c for i in 0..100000 { echo whatever } | grid"
User time (seconds): 0.14
System time (seconds): 0.05
Percent of CPU this job got: 33%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.60
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 48272
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 1
Minor (reclaiming a frame) page faults: 10582
Voluntary context switches: 286
Involuntary context switches: 831
Swaps: 0
File system inputs: 56
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
```
* Allow range in 'drop nth'
* Unit tests for drop nth range
* Add range case to the description
* Fix description 2
* format fixes
* Fix example and some refactoring
* clippy fixes
* fix into filesize tests and filesize
* tweaks
* added span back for like the 10th time
* Update filesize.rs
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
* query command with json, web, xml
* query xml now working
* clippy
* comment out web tests
* Initial work on query web
For now we can query everything except tables
* Support for querying tables
Now we can query multiple tables just like before, now the only thing
missing is the test coverage
* Revert "Query plugin"
* augment `ps -l` on windows to display more info
Co-authored-by: Luccas Mateus de Medeiros Gomes <luccasmmg@gmail.com>
* Port update cells command
Clean up, nicer match statements in UpdateCellsIterator
Return columns flag into HashSet errors
Add FIXME: for update cell behavior on nested lists
* Fix: process cells for Record when no columns are specified
* Fix: address clippy lints for unwrap and into_iter
* Fix: don't step into lists and don't bind $it var
* Add rotate command
* Add rotate counter clockwise
* Fix comments in the code
* Fix clippy warnings
* Fix comment
* Fix wrong step for non even table sizes
* Fix comment for moving through array
* Refactor rotate and have only one command with a --ccw flag for counter-clockwise rotation. By default, rotate is clockwise
* Update usage description
* Add `Find` command
* Complete rustdoc for test `Value` constructors
* Use `Option::unwrap_or` instead of match
* Add `Value::test_filesize` constructor
* Handle searching for terms in `find`
* Fix `find` command signature
* Return multiple elements when `find`ing by predicate
* Do not accept rest parameter with predicate
* Handle `CellPath` in `r#in` and `not_in` for `Find`
* Use `PipelineData::filter`
* Add custom error for path not being a directory
* Fix cd issue with cd-ing into a file
* Keep formatting style as before
* Check if path is not a directory and return error if that's the case
* Add example test to zip
* Port merge command from Nushell
On top of the original merge, this one should not collect a stream
returned from the merged block and allows merging records.
* Switch to short-names when the path is a relative_path (a dir) and exit with an error if the path does not exist
* Remove debugging print line
* Show relative filenames... It does not work yet for ls ../
* Try something else to fix relative paths... it works, but the ../ code part is not very pretty
* Add canonicalize check and remove code clones
* Fix the canonicalize_with issue pointed out by kubouch. Not sure the prefix_str is what kubouch suggested
* Fix the canonicalize_with issue pointed out by kubouch. Not sure the prefix_str is what kubouch suggested
* Add single-dot expansion to nu-path
* Move value path expansion from parser to eval
Fixes#745
* Remove single dot expansion from parser
It is not necessary since it will get expanded anyway in the eval.
* Fix ls to display globs with relative paths
* Use pathdiff crate to get relative paths for ls
Co-authored-by: Stefan Stanciulescu <contact@stefanstanciulescu.com>
* Switch to short-names when the path is a relative_path (a dir) and exit with an error if the path does not exist
* Remove debugging print line
* Show relative filenames... It does not work yet for ls ../
* Try something else to fix relative paths... it works, but the ../ code part is not very pretty
* Add canonicalize check and remove code clones
* Fix the canonicalize_with issue pointed out by kubouch. Not sure the prefix_str is what kubouch suggested
* Fix the canonicalize_with issue pointed out by kubouch. Not sure the prefix_str is what kubouch suggested
* Make env var eval order during "use" deterministic
Fixes#726.
* Merge delta after getting config
To make sure env vars are all in the engine state and not in the stack.
* Move fetch to extra
* Move byte stream code to a function instead of copying it twice
* Fix formatting issues
* Make fetch a default command
* Fix formatting
* Use only $nu.env.PWD for getting current directory
Because setting and reading to/from std::env changes the global state
shich is problematic if we call `cd` from multiple threads (e.g., in a
`par-each` block).
With this change, when engine-q starts, it will either inherit existing
PWD env var, or create a new one from `std::env::current_dir()`.
Otherwise, everything that needs the current directory will get it from
`$nu.env.PWD`. Each spawned external command will get its current
directory per-process which should be thread-safe.
One thing left to do is to patch nu-path for this as well since it uses
`std::env::current_dir()` in its expansions.
* Rename nu-path functions
*_with is not *_relative which should be more descriptive and frees
"with" for use in a followup commit.
* Clone stack every each iter; Fix some commands
Cloning the stack each iteration of `each` makes sure we're not reusing
PWD between iterations.
Some fixes in commands to make them use the new PWD.
* Post-rebase cleanup, fmt, clippy
* Change back _relative to _with in nu-path funcs
Didn't use the idea I had for the new "_with".
* Remove leftover current_dir from rebase
* Add cwd sync at merge_delta()
This makes sure the parser and completer always have up-to-date cwd.
* Always pass absolute path to glob in ls
* Do not allow PWD a relative path; Allow recovery
Makes it possible to recover PWD by proceeding with the REPL cycle.
* Clone stack in each also for byte/string stream
* (WIP) Start moving env variables to engine state
* (WIP) Move env vars to engine state (ugly)
Quick and dirty code.
* (WIP) Remove unused mut and args; Fmt
* (WIP) Fix dataframe tests
* (WIP) Fix missing args after rebase
* (WIP) Clone only env vars, not the whole stack
* (WIP) Add env var clone to `for` loop as well
* Minor edits
* Refactor merge_delta() to include stack merging.
Less error-prone than doing it manually.
* Clone env for each `update` command iteration
* Mark env var hidden only when found in eng. state
* Fix clippt warnings
* Add TODO about env var reading
* Do not clone empty environment in loops
* Remove extra cwd collection
* Split current_dir() into str and path; Fix autocd
* Make completions respect PWD env var
* Port fetch to engine-q
* Fix check for path as a string
* Add a timeout flag and fix some span issues
* Add a temporary fetch command that returns byte streams. Got rid of async stuff as we're using the blocking feature of tokio
* More tweaks for the bytestream
* Rewrite fetch using ByteStreams
* buffer read on bytes directly
Co-authored-by: Stefan Stanciulescu <contact@stefanstanciulescu.com>
* get_columns is working in the columns command
* the new location of the get_columns method is nu-protocol/src/column.rs
* reference the new location of the get_columns method
* move get_columns to nu-engine
* feat(into): add example of into-bool
* feat(into): add convert from int and float
* feat(into): add converting string to bool
* feat(into): add converting value in table
* fix(into): update error
* fix(into): update span for example
* chore(into): update signature description
* float comparison using epsilon
* Update bool.rs
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
* A first working version of flatten. Needs a lot of cleanup. Committing to have a working version
* Typo fix
* Flatten tests pass
* Final cleanup, ready for push
* Final cleanup, ready for push
* Final cleanup, ready for push
* Final cleanup, ready for push
* Update flatten.rs
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
* Proof of concept treating env vars as Values
* Refactor env var collection and method name
* Remove unnecessary pub
* Move env translations into a new file
* Fix LS_COLORS to support any Value
* Fix spans during env var translation
* Add span to env var in cd
* Improve error diagnostics
* Fix non-string env vars failing string conversion
* Make PROMPT_COMMAND a Block instead of String
* Record host env vars to a fake file
This will give spans to env vars that would otherwise be without one.
Makes errors less confusing.
* Add 'env' command to list env vars
It will list also their values translated to strings
* Sort env command by name; Add env var type
* Remove obsolete test
* Porting 'ansi' command from nushell to engine-q
* Added StrCollect to example_test.rs to allow example tests to run
* Run 'cargo fmt' to fix formatting
* Update command.rs
* Update command.rs
* Update command.rs
* Added a category
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
I removed the Inflector dependency in favor of heck for two reasons:
- to close#3674.
- heck seems simpler and actively maintained
We could probably alter the structure of the `str_` module to expose the
individual casing behaviors better.
I did not feel as confident on changing those signatures.
So I took a lazier approach of a macro in the `mod.rs` that creates the public
shimming function to heck's traits.
* First iteration of the version command
* Cleanup
* Fix the installed plugins bug
* Fix fmt check issue
* Fix clippy warning
* Fixing all clippy warnings
* Remove old code
* Sort default context items categorically
* Separate commands in multiple statements
* Use curly braces instead of square brackets
This prevents undesired reformatting.
* MathEval Variance and Stddev
* Fix tests and linting
* Typo
* Deal with streams when they are not tables
* First draft of these commands
* To MD
* To md and to html
* Fixed cargo and to_md
* `into_abbreviated_string` instead of `into_string`
* Changed how inner tables are displayed
* port over the nth command from nushell
* remove a line of redundant code
* must sort the rows or else if the rows are not from low to high this crashes engine-q
* Port str to-decimal to into decimal command. Add also a Value::test_float function for tests only
* Add support for handling integers into decimals and fix issues with error span
* Remember environment variables from previous scope
* Re-introduce env var hiding
Right now, hiding decls is broken
* Re-introduce hidden field of import patterns
All tests pass now.
* Remove/Address tests TODOs
* Fix test typo; Report hiding error
* Add a few more tests
* Fix wrong expected test result
* add icons to grid output. still needs cleanup
* working but adds a dependency on ansi_term - need to fix that
* update styling, added lots of green code to icons
* clippy
* add config point for grid icons
* fix#4140
We are passing commands into a shell underneath but we were not
escaping arguments correctly. This new version of the code also takes
into consideration the ";" and "&" characters, which have special
meaning in shells.
We would probably benefit from a more robust way to join arguments to
shell programs. Python's stdlib has shlex.join, and perhaps we can
take that implementation as a reference.
* clean up escaping of posix shell args
I believe the right place to do escaping of arguments was in the
spawn_sh_command function. Note that this change prevents things like:
^echo "$(ls)"
from executing the ls command. Instead, this will just print
$(ls)
The regex has been taken from the python stdlib implementation of shlex.quote
* fix non-literal parameters and single quotes
* address clippy's comments
* fixup! address clippy's comments
* test that subshell commands are sanitized properly
* option to replace command same name
* moved order of custom value declarations
* arranged dataframe folders and objects
* sort help commands by name
* added dtypes function for debugging
* corrected name for dataframe commands
* command names using function
* have save --append create file if not exists
Currently, doing:
echo a | save --raw --append file.txt
will fail if file.txt does not exist. This PR changes that
* test that `save --append` will create new file
* MathEval Variance and Stddev
* Fix tests and linting
* Typo
* Deal with streams when they are not tables
* `from toml` command
* From ods
* From XLSX
* From ics
* From ini
* From vcf
* Forgot a eprintln!
* custom value trait
* functions for custom value trait
* custom trait behind flag
* open dataframe command
* command to-df for basic types
* follow path for dataframe
* dataframe operations
* dataframe not default feature
* custom as default feature
* corrected examples in command
* MathEval Variance and Stddev
* Fix tests and linting
* Typo
* Deal with streams when they are not tables
* `from toml` command
* From ods
* From XLSX
It's no longer attached to a Block. Makes access to overlays more
streamlined by removing this one indirection. Also makes it easier to
create standalone overlays without a block which might come in handy.
* Add 'expor env' dummy command
* (WIP) Abstract away module exportables as Overlay
* Switch to Overlays for use/hide
Works for decls only right now.
* Fix passing import patterns of hide to eval
* Simplify use/hide of decls
* Add ImportPattern as Expr; Add use env eval
Still no parsing of "export env" so I can't test it yet.
* Refactor export parsing; Add InternalError
* Add env var export and activation; Misc changes
Now it is possible to `use` env var that was exported from a module.
This commit also adds some new errors and other small changes.
* Add env var hiding
* Fix eval not recognizing hidden decls
Without this change, calling `hide foo`, the evaluator does not know
whether a custom command named "foo" was hidden during parsing,
therefore, it is not possible to reliably throw an error about the "foo"
name not found.
* Add use/hide/export env var tests; Cleanup; Notes
* Ignore hide env related tests for now
* Fix main branch merge mess
* Fixed multi-word export def
* Fix hiding tests on Windows
* Remove env var hiding for now
* MathEval Variance and Stddev
* Fix tests and linting
* Typo
* Deal with streams when they are not tables
* FromEml and FromUrl
Added tests for from eml
* MathEval Variance and Stddev
* Fix tests and linting
* Typo
* Deal with streams when they are not tables
* `from yaml` and `from yml`
`from yaml` and `from yml`
from yaml and from yml
* Fix collect_string
* Fix tests and linting
* Port str contains command
* Add another test case / example for str contains
* Port str downcase to engine-q
Co-authored-by: Stefan Stanciulescu <contact@stefanstanciulescu.com>
* initial commit of reverse
* reverse is working, now move on to the examples
* add in working examples for reverse
* #[allow(clippy::needless_collect)]
* Port camel case and kebab case
* Port pascal case
* Port snake case and screaming snake case
* Cleanup before PR
* Add back cell path support for str case commands
* Add cell path tests for str case command
* Revert "Add cell path tests for str case command"
This reverts commit a0906318d95fd2b5e4f8ca42f547a7e4c5db381a.
* Add cell path test cases for str case command
* Move cell path tests from tests.rs to Examples in each of the command's file
Co-authored-by: Stefan Stanciulescu <contact@stefanstanciulescu.com>
Now, Echo converts multiple values in a ValueStream, but it simply
forwards a single Value; if no PipelineData is detected as an input, an
empty string is returned as a single Value.
Values to echo need to be extracted from the call, and then converted
into PipelineData.
I also updated the first example so that its result is a List,
as in the reference implementation.
See cc3653cfd9 for more on the `-c` flag.
Co-authored-by: Andrés N. Robalino <andres@androbtech.com>
Co-authored-by: Andrés N. Robalino <andres@androbtech.com>
* compiles on nightly now. (breaking change)
* less deps
* Switch over to new resolver
(it's been stable for a while.)
* let's leave num-format for another PR
Very often we need to work with tables (say extracted from unstructured data or some
kind of final report, timeseries, and the like).
It's inevitable we will be having columns that we can't know beforehand what their names
will be, or how many.
Also, we may end up with certain cells having values we may want to remove as we explore.
Here, `update cells` fundamentally goes over every cell in the table coming in and updates
the cell's contents with the output of the block passed. Basic example here:
```
> [
[ ty1, t2, ty];
[ 1, a, $nothing]
[(wrap), (0..<10), 1Mb]
[ 1s, ({}), 1000000]
[ $true, $false, ([[]])]
] | update cells { describe }
───┬───────────────────────┬───────────────────────────┬──────────
# │ ty1 │ t2 │ ty
───┼───────────────────────┼───────────────────────────┼──────────
0 │ integer │ string │ nothing
1 │ row Column(table of ) │ range[[integer, integer)] │ filesize
2 │ string │ nothing │ integer
3 │ boolean │ boolean │ table of
───┴───────────────────────┴───────────────────────────┴──────────
```
and another one (in the examples) for cases, say we have a timeseries table generated and
we want to remove the zeros and have empty strings and save it out to something like CSV.
```
> [
[2021-04-16, 2021-06-10, 2021-09-18, 2021-10-15, 2021-11-16, 2021-11-17, 2021-11-18];
[ 37, 0, 0, 0, 37, 0, 0]
] | update cells {|value| i
if ($value | into int) == 0 {
""
} {
$value
}
}
───┬────────────┬────────────┬────────────┬────────────┬────────────┬────────────┬────────────
# │ 2021-04-16 │ 2021-06-10 │ 2021-09-18 │ 2021-10-15 │ 2021-11-16 │ 2021-11-17 │ 2021-11-18
───┼────────────┼────────────┼────────────┼────────────┼────────────┼────────────┼────────────
0 │ 37 │ │ │ │ 37 │ │
───┴────────────┴────────────┴────────────┴────────────┴────────────┴────────────┴────────────
```
* Change path join signature
* Appending now works without flag
* Column path operation is behind a -c flag
* Move column path arg retrieval to a function
Also improves errors
* Fix path join tests
* Propagate column path changes to all path commands
* Update path command examples with columns paths
* Modernize path command examples by removing "echo"
* Improve structured path error message
* Fix typo
* Expand path when converting value -> PathBuf
Also includes Tagged<PathBuf>.
Fixes#3605
* Expand path for PATH env. variable
Fixes#1834
* Remove leftover Cows after nu-path refactor
There were some unnecessary Cow conversions leftover from the old
nu-path implementation.
* Use canonicalize in source command; Improve errors
Previously, `source` used `expand_path()` which does not follow
symlinks.
As a follow up, I improved the source error messages so they now tell
why the source file could not be canonicalized or read into string.
```
> [
[ msg, labels, span];
["The message", "Helpful message here", ([[start, end]; [0, 141]])]
] | error make
error: The message
┌─ shell:1:1
│
1 │ ╭ [
2 │ │ [ msg, labels, span];
3 │ │ ["The message", "Helpful message here", ([[start, end]; [0, 141]])]
│ ╰─────────────────────────────────────────────────────────────────────^ Helpful message here
```
Adding a more flexible approach for creating error values. One use case, for instance is the
idea of a test framework. A failed assertion instead of printing to the screen it could create
tables with more details of the failed assertion and pass it to this command for making a full
fledge error that Nu can show. This can (and should) be extended for capturing error values as well
in the pipeline. One could also use it for inspection.
For example: `.... | error inspect { # inspection here }`
or "error handling" as well, like so: `.... | error capture { fix here }`
However, we start here only with `error make` that creates an error value for you with limited support for the time being.
* Add subcommand `into filesize`
It's currently not possible to convert a number or a string containing a number
into a filesize. The only way to create an instance of filesize type today is
with a literal in nushell syntax. This commit adds the `into filesize`
subcommand so that file sizes can be created from the outputs of programs
producing numbers or strings, like standard unix tools.
There is a limitation with this - it doesn't currently parse values like `10 MB`
or `10 MiB`, it can only look at the number itself. If the desire is there, more
flexible parsing can be added.
* fixup! Add subcommand `into filesize`
* fixup! Add subcommand `into filesize`
* feat: spawn the executables directly if possible
This pull request changes nu-command so that it spawns the process directly if:
- They are a `.exe` on Windows
- They are not a `.sh` or `.bash` on not windows.
Benefits:
- As I explained in [this comment](https://github.com/nushell/nushell/issues/3898#issuecomment-894000812), this is another step towards making Nushell a standalone shell, that doesn't need to shell out unless it is running a script for a particular shell (cmd, sh, ps1, etc.).
- Fixes the bug with multiline strings
- Better performance due to direct spawning.
For example, this script shows ~20 ms less latency.
After:
```nu
C:\> benchmark { node -e 'console.log("sssss")' }
───┬──────────────────
# │ real time
───┼──────────────────
0 │ 63ms 921us 600ns
───┴──────────────────
```
Before
```nu
C:\> benchmark { node -e 'console.log("sssss")' }
───┬──────────────────
# │ real time
───┼──────────────────
0 │ 79ms 136us 800ns
───┴──────────────────
```
Fixes#3898
* fix: make which dependency optional
Also fixes clippy warnings
* refactor: refactor spawn_exe, spawn_cmd, spawn_sh, and spawn_any
* fix: use which feature instead of which-support
* fix: use which_in to use the cwd of nu
* fix: use case insensitive comparison of the extensions
Sometimes the case of the extension is uppercased by the "which_in" function
Also use unix instead of not windows. Some os might not have sh support
* Resolve rebase artifacts
* Remove leftover dependencies on removed feature
* Remove unnecessary 'pub'
* Start taking notes and fooling around
* Split canonicalize to two versions; Add TODOs
One that takes `relative_to` and one that doesn't.
More TODO notes.
* Merge absolutize to and rename resolve_dots
* Add custom absolutize fn and use it in path expand
* Convert a couple of dunce::canonicalize to ours
* Update nu-path description
* Replace all canonicalize with nu-path version
* Remove leftover dunce dependencies
* Fix broken autocd with trailing slash
Trailing slash is preserved *only* in paths that do not contain "." or
"..". This should be fixed in the future to cover all paths but for now
it at least covers basic cases.
* Use dunce::canonicalize for canonicalizing
* Alow cd recovery from non-existent cwd
* Disable removed canonicalize functionality tests
Remove unused import
* Break down nu-path into separate modules
* Remove unused public imports
* Remove abundant cow mapping
* Fix clippy warning
* Reformulate old canonicalize tests to expand_path
They wouldn't work with the new canonicalize.
* Canonicalize also ~ and ndots; Unify path joining
Also, add doc comments in nu_path::expansions.
* Add comment
* Avoid expanding ndots if path is not valid UTF-8
With this change, no lossy path->string conversion should happen in the
nu-path crate.
* Fmt
* Slight expand_tilde refactor; Add doc comments
* Start nu-path integration tests
* Add tests TODO
* Fix docstring typo
* Fix some doc strings
* Add README for nu-path crate
* Add a couple of canonicalize tests
* Add nu-path integration tests
* Add trim trailing slashes tests
* Update nu-path dependency
* Remove unused import
* Regenerate lockfile
* Allow different names for ...rest
* Resolves#3945
* This change requires an explicit name for the rest argument in `WholeStreamCommand`,
which is why there are so many changed files.
* Remove redundant clone
* Add tests
* Allow environment variables to be hidden
This change allows environment variables in Nushell to have a value of
`Nothing`, which can be set by the user by passing `$nothing` to
`let-env` and friends.
Environment variables with a value of Nothing behave as if they are not
set at all. This allows a user to shadow the value of an environment
variable in a parent scope, effectively removing it from their current
scope. This was not possible before, because a scope can not affect its
parent scopes.
This is a workaround for issues like #3920.
Additionally, this allows a user to simultaneously set, change and
remove multiple environment variables via `load-env`. Any environment
variables set to $nothing will be hidden and thus act as if they are
removed. This simplifies working with virtual environments, which rely
on setting multiple environment variables, including PATH, to specific
values, and remove/change them on deactivation.
One surprising behavior is that an environment variable set to $nothing
will act as if it is not set when querying it (via $nu.env.X), but it is
still possible to remove it entirely via `unlet-env`. If the same
environment variable is present in the parent scope, the value in the
parent scope will be visible to the user. This might be surprising
behavior to users who are not familiar with the implementation details.
An additional corner case is the the shorthand form of `with-env` does
not work with this feature. Using `X=$nothing` will set $nu.env.X to the
string "$nothing". The long-form works as expected: `with-env [X
$nothing] {...}`.
* Remove unused import
* Allow all primitives to be convert to strings
Given we can write nu scripts. As the codebase grows, splitting into many smaller nu scripts is necessary.
In general, when we work with paths and files we seem to face quite a few difficulties. Here we just tackle one of them and it involves sourcing
files that also source other nu files and so forth. The current working directory becomes important here and being on a different directory
when sourcing scripts will not work. Mostly because we expand the path on the current working directory and parse the files when a source command
call is done.
For the moment, we introduce a `lib_dirs` configuration value and, unfortunately, introduce a new dependency in `nu-parser` (`nu-data`) to get
a handle of the configuration file to retrieve it. This should give clues and ideas as the new parser engine continues (introduce a way to also know paths)
With this PR we can do the following:
Let's assume we want to write a nu library called `my_library`. We will have the code in a directory called `project`: The file structure will looks like this:
```
project/my_library.nu
project/my_library/hello.nu
project/my_library/name.nu
```
This "pattern" works well, that is, when creating a library have a directory named `my_library` and next to it a `my_library.nu` file. Filling them like this:
```
source my_library/hello.nu
source my_library/name.nu
```
```
def hello [] {
"hello world"
}
```
```
def name [] {
"Nu"
end
```
Assuming this `project` directory is stored at `/path/to/lib/project`, we can do:
```
config set lib_dirs ['path/to/lib/project']
```
Given we have this `lib_dirs` configuration value, we can be anywhere while using Nu and do the following:
```
source my_library.nu
echo (hello) (name)
```
