* Playground infraestructure (tests, etc) additions.
A few things to note:
* Nu can be started with a custom configuration file (`nu --config-file /path/to/sample_config.toml`). Useful for mocking the configuration on test runs.
* When given a custom configuration file Nu will save any changes to the file supplied appropiately.
* The `$nu.config-path` variable either shows the default configuration file (or the custom one, if given)
* We can now run end to end tests with finer grained control (currently, since this is baseline work, standard out) This will allow to check things like exit status, assert the contents with a format, etc)
* Remove (for another PR)
* update docs to refer to length instead of count
* rename count to length
* change all occurrences of 'count' to 'length' in tests
* format length command
* Refactor path subcommand argument handling
DefaultArguments are no longer passed to each subcommand. Instead, each
subcommand has its own Path<xxx>Arguments. This means that it is no
longer necessary to edit every single path subcommand source file when
changing the arguments struct.
* Add new path join subcommand
Makes it easier to create new paths. It's just a wrapper around Rust's
Path.join().
`drop` is used for removing the last row. Passing a number allows dropping N rows.
Here we introduce the same logic for dropping columns instead.
You can certainly remove columns by using `reject`, however, there could be cases
where we are interested in removing columns from tables that contain, say, a big
number of columns. Using `reject` becomes impractical, especially when you don't
care about the column names that could either be known or not known when exploring
tables.
```
> echo [[lib, extension]; [nu-core, rs] [rake, rb]]
─────────┬───────────
lib │ extension
─────────┼───────────
nu-core │ rs
rake │ rb
─────────┴───────────
```
```
> echo [[lib, extension]; [nu-core, rs] [rake, rb]] | drop column
─────────
lib
─────────
nu-core
rake
─────────
```
There are many use cases. Here we introduce the following:
- The rows can be rolled `... | roll` (up) or `... | roll down`
- Columns can be rolled too (the default is on the `left`, you can pass `... | roll column --opposite` to roll in the other direction)
- You can `roll` the cells of a table and keeping the header names in the same order (`... | roll column --cells-only`)
- Above examples can also be passed (Ex. `... | roll down 3`) a number to tell how many places to roll.
Basic working example with rolling columns:
```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8
───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
# │ bit1 │ bit2 │ bit3 │ bit4 │ bit5 │ bit6 │ bit7 │ bit8
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
0 │ 0 │ 0 │ 0 │ 0 │ 0 │ 1 │ 0 │ 0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```
We want to "shift" three bits to the left of the bitstring (four in decimal), let's try it:
```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8
| roll column 3
───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
# │ bit4 │ bit5 │ bit6 │ bit7 │ bit8 │ bit1 │ bit2 │ bit3
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
0 │ 0 │ 0 │ 1 │ 0 │ 0 │ 0 │ 0 │ 0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```
The tables was rolled correctly (32 in decimal, for above bitstring). However, the *last three header names* look confusing.
We can roll the cell contents only to fix it.
```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8
| roll column 3 --cells-only
───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
# │ bit1 │ bit2 │ bit3 │ bit4 │ bit5 │ bit6 │ bit7 │ bit8
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
0 │ 0 │ 0 │ 1 │ 0 │ 0 │ 0 │ 0 │ 0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```
There we go. Let's compute it's decimal value now (should be 32)
```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| roll column 3 --cells-only
| pivot bit --ignore-titles
| get bit
| reverse
| each --numbered { = $it.item * (2 ** $it.index) }
| math sum
32
```
* move commands, futures.rs, script.rs, utils
* move over maybe_print_errors
* add nu_command crate references to nu_cli
* in commands.rs open up to pub mod from pub(crate)
* nu-cli, nu-command, and nu tests are now passing
* cargo fmt
* clean up nu-cli/src/prelude.rs
* code cleanup
* for some reason lex.rs was not formatted, may be causing my error
* remove mod completion from lib.rs which was not being used along with quickcheck macros
* add in allow unused imports
* comment out one failing external test; comment out one failing internal test
* revert commenting out failing tests; something else might be going on; someone with a windows machine should check and see what is going on with these failing windows tests
* Update Cargo.toml
Extend the optional features to nu-command
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
