# Description
The name of the `group` command is a little unclear/ambiguous.
Everything I look at it, I think of `group-by`. I think `chunks` more
clearly conveys what the `group` command does. Namely, it divides the
input list into chunks of a certain size. For example,
[`slice::chunks`](https://doc.rust-lang.org/std/primitive.slice.html#method.chunks)
has the same name. So, this PR adds a new `chunks` command to replace
the now deprecated `group` command.
The `chunks` command is a refactored version of `group`. As such, there
is a small performance improvement:
```nushell
# $data is a very large list
> bench { $data | chunks 2 } --rounds 30 | get mean
474ms 921µs 190ns
# deprecation warning was disabled here for fairness
> bench { $data | group 2 } --rounds 30 | get mean
592ms 702µs 440ns
> bench { $data | chunks 200 } --rounds 30 | get mean
374ms 188µs 318ns
> bench { $data | group 200 } --rounds 30 | get mean
481ms 264µs 869ns
> bench { $data | chunks 1 } --rounds 30 | get mean
642ms 574µs 42ns
> bench { $data | group 1 } --rounds 30 | get mean
981ms 602µs 513ns
```
# User-Facing Changes
- `group` command has been deprecated in favor of new `chunks` command.
- `chunks` errors when given a chunk size of `0` whereas `group` returns
chunks with one element.
# Tests + Formatting
Added tests for `chunks`, since `group` did not have any tests.
# After Submitting
Update book if necessary.