# Description
_(Thank you for improving Nushell. Please, check our [contributing
guide](../CONTRIBUTING.md) and talk to the core team before making major
changes.)_
_(Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.)_
# User-Facing Changes
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
# 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.
close#7591
I tend to think it must be addressed.
But I'd verify it @rgwood.
PS: I've noticed how `table -e` and `table` with the same width wraps a
bit differently sometimes. (I guess it also must be addressed......)
Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>
# Description
Inspired by #7592
For brevity use `Value::test_{string,int,float,bool}`
Includes fixes to commands that were abusing `Span::test_data` in their
implementation. Now the call span is used where possible or the explicit
`Span::unknonw` is used.
## Command fixes
- Fix abuse of `Span::test_data()` in `query_xml`
- Fix abuse of `Span::test_data()` in `term size`
- Fix abuse of `Span::test_data()` in `seq date`
- Fix two abuses of `Span::test_data` in `nu-cli`
- Change `Span::test_data` to `Span::unknown` in `keybindings listen`
- Add proper call span to `registry query`
- Fix span use in `nu_plugin_query`
- Fix span assignment in `select`
- Use `Span::unknown` instead of `test_data` in more places
## Other
- Use `Value::test_int`/`test_float()` consistently
- More `test_string` and `test_bool`
- Fix unused imports
# User-Facing Changes
Some commands may now provide more helpful spans for downstream use in
errors
# Description
The message reads "You must use one of the following subcommands. Using
this command as-is will only produce this help message." and is added to
commands like `into`, `bytes`, `str`, etc.
# User-Facing Changes
See above.
# 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.
# Description
This is for consistency with the new `values` command. Previously it
would return a completely empty record (??!) when given an
incorrectly-typed value.
# User-Facing Changes
See title.
# 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.
Closes#7572 by adding a cache for compiled regexes of type
`Arc<Mutex<LruCache<String, Regex>>>` to `EngineState` .
The cache is limited to 100 entries (limit chosen arbitrarily) and
evicts least-recently-used items first.
This PR makes a noticeable difference when using regexes for
`color_config`, e.g.:
```bash
#first set string formatting in config.nu like:
string: { if $in =~ '^#\w{6}$' { $in } else { 'white' } }`
# then try displaying and exploring a table with many strings
# this is instant after the PR, but takes hundreds of milliseconds before
['#ff0033', '#0025ee', '#0087aa', 'string', '#4101ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff']
```
## New dependency (`lru`)
This uses [the popular `lru` crate](https://lib.rs/crates/lru). The new
dependency adds 19.8KB to a Linux release build of Nushell. I think this
is OK, especially since the crate can be useful elsewhere in Nu.
# Description
This PR allows `wrap` to pass through metadata.
# User-Facing Changes
This change allows this:
<img width="789" alt="Screenshot 2022-12-23 at 3 12 37 PM"
src="https://user-images.githubusercontent.com/343840/209406010-1da9b814-1892-4961-bb01-9f88ddc83474.png">
Instead of this:
<img width="786" alt="Screenshot 2022-12-23 at 3 12 48 PM"
src="https://user-images.githubusercontent.com/343840/209406021-6e5eb860-0911-42c4-a39e-5fe76c61af03.png">
Strangely enough, this command doesn't result in LS_COLORS `(ls |
values).0 | wrap name`
/cc @webbedspace - we were talking about LS_COLORS in `values` earlier.
# 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.
# Description
Certain commands that operate on tables also work on bare records, but
their type sig didn't reflect that. This corrects this.
I did not fix certain commands which, I feel, currently give unintended
behaviour when given plain records. These are `sort-by` and `uniq-by`.
Also corrected the wording of some stuff in headers.rs, and removed a
wrong comment in insert.rs.
# User-Facing Changes
See above.
# 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.
# Description
* I was dismayed to discover recently that UnsupportedInput and
TypeMismatch are used *extremely* inconsistently across the codebase.
UnsupportedInput is sometimes used for input type-checks (as per the
name!!), but *also* used for argument type-checks. TypeMismatch is also
used for both.
I thus devised the following standard: input type-checking *only* uses
UnsupportedInput, and argument type-checking *only* uses TypeMismatch.
Moreover, to differentiate them, UnsupportedInput now has *two* error
arrows (spans), one pointing at the command and the other at the input
origin, while TypeMismatch only has the one (because the command should
always be nearby)
* In order to apply that standard, a very large number of
UnsupportedInput uses were changed so that the input's span could be
retrieved and delivered to it.
* Additionally, I noticed many places where **errors are not propagated
correctly**: there are lots of `match` sites which take a Value::Error,
then throw it away and replace it with a new Value::Error with
less/misleading information (such as reporting the error as an
"incorrect type"). I believe that the earliest errors are the most
important, and should always be propagated where possible.
* Also, to standardise one broad subset of UnsupportedInput error
messages, who all used slightly different wordings of "expected
`<type>`, got `<type>`", I created OnlySupportsThisInputType as a
variant of it.
* Finally, a bunch of error sites that had "repeated spans" - i.e. where
an error expected two spans, but `call.head` was given for both - were
fixed to use different spans.
# Example
BEFORE
```
〉20b | str starts-with 'a'
Error: nu:🐚:unsupported_input (link)
× Unsupported input
╭─[entry #31:1:1]
1 │ 20b | str starts-with 'a'
· ┬
· ╰── Input's type is filesize. This command only works with strings.
╰────
〉'a' | math cos
Error: nu:🐚:unsupported_input (link)
× Unsupported input
╭─[entry #33:1:1]
1 │ 'a' | math cos
· ─┬─
· ╰── Only numerical values are supported, input type: String
╰────
〉0x[12] | encode utf8
Error: nu:🐚:unsupported_input (link)
× Unsupported input
╭─[entry #38:1:1]
1 │ 0x[12] | encode utf8
· ───┬──
· ╰── non-string input
╰────
```
AFTER
```
〉20b | str starts-with 'a'
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #1:1:1]
1 │ 20b | str starts-with 'a'
· ┬ ───────┬───────
· │ ╰── only string input data is supported
· ╰── input type: filesize
╰────
〉'a' | math cos
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #2:1:1]
1 │ 'a' | math cos
· ─┬─ ────┬───
· │ ╰── only numeric input data is supported
· ╰── input type: string
╰────
〉0x[12] | encode utf8
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #3:1:1]
1 │ 0x[12] | encode utf8
· ───┬── ───┬──
· │ ╰── only string input data is supported
· ╰── input type: binary
╰────
```
# User-Facing Changes
Various error messages suddenly make more sense (i.e. have two arrows
instead of one).
# 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.
This PR changes `to text` so that when given a `ListStream`, it streams
the incoming values instead of collecting them all first.
The easiest way to observe/verify this PR is to convert a list to a very
slow `ListStream` with `each`:
```bash
ls | get name | each {|n| sleep 1sec; $n} | to text
```
The `to text` output will appear 1 item at a time.
# Description
Prevent a situation where a `def` can't be run due to a poor choice of
name. Related: #6335. Hashtags, numbers and filesizes are no longer
allowed. `alias` check has been moved because previously `alias 123`
would be caught but `alias "123"` would be permitted.
# User-Facing Changes
Some definitions can no longer be made, but because they couldn't be run
previously anyway, it doesn't really matter.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
# Description
Purely for consistency, various remaining instances of `$nothing`
(almost all of which were in test code) have been changed to `null`.
Now, the only place that refers to `$nothing` is the parser code which
implements it.
# User-Facing Changes
The default config.nu now uses `null` in certain places where it used
`$nothing`.
# 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.
# Description
This now works:
```
try { 'x' | math abs } catch { $in }
```
# User-Facing Changes
See above.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
# Description
Fixes#7529.
# User-Facing Changes
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
# Description
Currently, `filesize_format`/`filesize_metric` conflicts are resolved as
follows: if the `filesize_format` ends in "ib", then that overrides
`filesize_metric`, otherwise, `filesize_metric` overrides
`filesize_format`. This removes this difficult-to-predict asymmetric
behaviour, and makes it so that `filesize_metric` always overrides
`filesize_format`.
This also adds tests for `$env.config.filesize.format` and
`$env.config.filesize.metric` values.
REMINDER: `filesize_metric` means "increments of 1000", and refers to
KB-MB-GB-TB etc.
# User-Facing Changes
See above.
# 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: Darren Schroeder <343840+fdncred@users.noreply.github.com>
# Description
Fixes#5996
Just found a relative easy way to fix the issue
# User-Facing Changes
```
❯ open $nu.plugin-path | from nuon
Error:
× error when loading nuon text
╭─[entry #36:1:1]
1 │ open $nu.plugin-path | from nuon
· ────┬────
· ╰── could not load nuon text
╰────
Error:
× Error when loading
❯ open $nu.config-path | from nuon
Error:
× error when loading nuon text
╭─[entry #37:1:1]
1 │ open $nu.config-path | from nuon
· ────┬────
· ╰── could not load nuon text
╰────
Error:
× error when loading
```
# 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.
`proptest` caught a failing test condition for `&&` as a literal string. It requires a quotation to be parsed correctly by current `from nuon`
https://github.com/nushell/nushell/actions/runs/3753242377/jobs/6376308675
The change in the parser that now returns an error was introduced by https://github.com/nushell/nushell/pull/7241
This in theory doesn't have to be an error (it is a diagnostic for nushell code) but it is probably better safe than sorry to require quotation here.
- Add a test for `&&` in `to nuon` from proptest fail
- Fix `to nuon` generating invalid `&&` literal
- Add a test for `,` in `to nuon`/`from nuon` cycle
- Bonus: should already be properly quoted
`table` handles slow `ListStream`s in a special way: every 100 items, it
checks whether 1 second has elapsed since the last table page, and if so
it outputs a new page with all the items in its buffer.
**I would like to remove the "every 100 items" condition and always
output whatever we have if a second has elapsed.** I think this will be
a better user experience for very slow streams.
As a motivating example, imagine tailing a log file and doing some
string parsing/projection on each line. The user will be really annoyed
if they have to wait for 100 lines to be written to the log before
seeing new results!
I did some quick performance measurements with Criterion, and the
elapsed-time check takes about 16ns on my machine (Linux, 12900k). I
think the performance impact of checking that for every item will be
negligible.
# Description
_(Thank you for improving Nushell. Please, check our [contributing
guide](../CONTRIBUTING.md) and talk to the core team before making major
changes.)_
_(Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.)_
# User-Facing Changes
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
# 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.
# Description
General tree shaking through `cargo +nightly udeps` and moving mentions
of `nu-test-support` to the dev deps.
Also since #7488 no separate import of `nu-path` necessary
cc @webbedspace
# Description
This turns off `cd` abbreviations by default
# User-Facing Changes
`cd` goes back to requiring a name with the default configuration
# 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.
ref #7339 - This PR updates explore to take some of the colors from
nushell, namely the line colors and the ls_colors.
note: Not sure why this regression appeared maybe it's a feature or it's
no longer supposed to be supported?
Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>
Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
> I'm not sure how i feel about that. I mean if there are a lot of
columns, it should probably have a max width so 1 column doesn't take
the entire width of your screen. Ideally it would work closely like
table worked before we migrated to tabled, as far as how column widths
were allocated.
I believe it still not completely matched.
*To be honest I am not against the #7446 approach.
The PR makes a switch between logics on a premise of `termwidth`.
So if `termwidth > 120` we start prioritizing amount of columns we can
show (We try to show as many columns as we can).
Otherwise we do what I've described in #7446 (We show the least columns
but with least truncation involvement).
In case it's OK,
I guess we could make the value configurable.
cc @fdncred
ref #7446
Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>
A few small tweaks to the new `explore` command:
1. Rewrote the help text a bit.
1. I think it's important to mention `:try` up front.
2. Removed the info about `:help foo` because it's currently supported
by very few subcommands
2. Make `exit_esc` default to true. I want to avoid people getting stuck
in `explore` like they get stuck in Vim
3. ~~Always show the help message ("For help type :help") on startup~~
1. The message is small+unobtrusive and I don't this is worth a
configuration item
4. Exit the information view when Escape is pressed
5. General typo+grammar cleanup
cc: @zhiburt @fdncred
# Description
See title.
# User-Facing Changes
See title.
# 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.
A follow-up to #7497. That change made it so that `get foo` would
eliminate non-record rows; I think that was an unintentional and
undesirable side-effect.
Before #7497:
```bash
〉[$nothing, { item: "foo" }] | get item
╭───┬─────╮
│ 0 │ │
│ 1 │ foo │
╰───┴─────╯
```
After #7497:
```bash
〉[$nothing, {item: "foo"}] | get item
╭───┬─────╮
│ 0 │ foo │
╰───┴─────╯
```
After this PR:
```bash
〉[$nothing, { item: "foo" }] | get item
╭───┬─────╮
│ 0 │ │
│ 1 │ foo │
╰───┴─────╯
```
cc: @merelymyself
# Description
Follow up to #7141 to map @webbedspace's rgb colors to xterm 256 color
indexes. Also added the xterm 256 named colors to `ansi --list` in the
process.
The few dozen or so names that were duplicate in the xterm 256 names
from [here](https://www.ditig.com/256-colors-cheat-sheet) were renamed
by appending a,b,c,d. So, instead of two blue3's there will be blue3a
and blue3b.
# User-Facing Changes
More colors.
# 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.
# Description
Closes#6909. You can now add closures to your `color_config` themes.
Whenever a value would be printed with `table`, the closure is run with
the value piped-in. The closure must return either a {fg,bg,attr} record
or a color name (`'light_red'` etc.). This returned style is used to
colour the value.
This is entirely backwards-compatible with existing config.nu files.
Example code excerpt:
```
let my_theme = {
header: green_bold
bool: { if $in { 'light_cyan' } else { 'light_red' } }
int: purple_bold
filesize: { |e| if $e == 0b { 'gray' } else if $e < 1mb { 'purple_bold' } else { 'cyan_bold' } }
duration: purple_bold
date: { (date now) - $in | if $in > 1wk { 'cyan_bold' } else if $in > 1day { 'green_bold' } else { 'yellow_bold' } }
range: yellow_bold
string: { if $in =~ '^#\w{6}$' { $in } else { 'white' } }
nothing: white
```
Example output with this in effect:
![2022-11-16 12 47 23 AM - style_computer
rs_-_nushell_-_VSCodium](https://user-images.githubusercontent.com/83939/201952558-482de05d-69c7-4bf2-91fc-d0964bf71264.png)
![2022-11-16 12 39 41 AM - style_computer
rs_-_nushell_-_VSCodium](https://user-images.githubusercontent.com/83939/201952580-2384bb86-b680-40fe-8192-71bae396c738.png)
![2022-11-15 09 21 54 PM - run_external
rs_-_nushell_-_VSCodium](https://user-images.githubusercontent.com/83939/201952601-343fc15d-e4a8-4a92-ad89-9a7d17d42748.png)
Slightly important notes:
* Some color_config names, namely "separator", "empty" and "hints", pipe
in `null` instead of a value.
* Currently, doing anything non-trivial inside a closure has an
understandably big perf hit. I currently do not actually recommend
something like `string: { if $in =~ '^#\w{6}$' { $in } else { 'white' }
}` for serious work, mainly because of the abundance of string-type data
in the world. Nevertheless, lesser-used types like "date" and "duration"
work well with this.
* I had to do some reorganisation in order to make it possible to call
`eval_block()` that late in table rendering. I invented a new struct
called "StyleComputer" which holds the engine_state and stack of the
initial `table` command (implicit or explicit).
* StyleComputer has a `compute()` method which takes a color_config name
and a nu value, and always returns the correct Style, so you don't have
to worry about A) the color_config value was set at all, B) whether it
was set to a closure or not, or C) which default style to use in those
cases.
* Currently, errors encountered during execution of the closures are
thrown in the garbage. Any other ideas are welcome. (Nonetheless, errors
result in a huge perf hit when they are encountered. I think what should
be done is to assume something terrible happened to the user's config
and invalidate the StyleComputer for that `table` run, thus causing
subsequent output to just be Style::default().)
* More thorough tests are forthcoming - ran into some difficulty using
`nu!` to take an alternative config, and for some reason `let-env config
=` statements don't seem to work inside `nu!` pipelines(???)
* The default config.nu has not been updated to make use of this yet. Do
tell if you think I should incorporate that into this.
# User-Facing Changes
See above.
# 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 --features=extra -- -D warnings -D
clippy::unwrap_used -A clippy::needless_collect` to check that you're
using the standard code style
- `cargo test --workspace --features=extra` 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.
`echo` tends to confuse new Nu users; they expect it to work like
`print` when it just passes a value to the next stage of the pipeline.
We haven't quite figured out what to do about `echo` in the long run,
but I think a good start is to remove `echo` from command examples where
it would be unnecessary and arguably unidiomatic.