# Description
This PR creates a new `Record` type to reduce duplicate code and
possibly bugs as well. (This is an edited version of #9648.)
- `Record` implements `FromIterator` and `IntoIterator` and so can be
iterated over or collected into. For example, this helps with
conversions to and from (hash)maps. (Also, no more
`cols.iter().zip(vals)`!)
- `Record` has a `push(col, val)` function to help insure that the
number of columns is equal to the number of values. I caught a few
potential bugs thanks to this (e.g. in the `ls` command).
- Finally, this PR also adds a `record!` macro that helps simplify
record creation. It is used like so:
```rust
record! {
"key1" => some_value,
"key2" => Value::string("text", span),
"key3" => Value::int(optional_int.unwrap_or(0), span),
"key4" => Value::bool(config.setting, span),
}
```
Since macros hinder formatting, etc., the right hand side values should
be relatively short and sweet like the examples above.
Where possible, prefer `record!` or `.collect()` on an iterator instead
of multiple `Record::push`s, since the first two automatically set the
record capacity and do less work overall.
# User-Facing Changes
Besides the changes in `nu-protocol` the only other breaking changes are
to `nu-table::{ExpandedTable::build_map, JustTable::kv_table}`.
# Description
Make sure that our different crates that contain commands can be
compiled in parallel.
This can under certain circumstances accelerate the compilation with
sufficient multithreading available.
## Details
- Move `help` commands from `nu-cmd-lang` back to `nu-command`
- This also makes sense as the commands are implemented in an
ANSI-terminal specific way
- Make `nu-cmd-lang` only a dev dependency for `nu-command`
- Change context creation helpers for `nu-cmd-extra` and
`nu-cmd-dataframe` to have a consistent api used in
`src/main.rs`:`get_engine_state()`
- `nu-command` now indepedent from `nu-cmd-extra` and `nu-cmd-dataframe`
that are now dependencies of `nu` directly. (change to internal
features)
- Fix tests that previously used `nu-command::create_default_context()`
with replacement functions
## From scratch compilation times:
just debug (dev) build and default features
```
cargo clean --profile dev && cargo build --timings
```
### before

### after

# User-Facing Changes
None direct, only change to compilation on multithreaded jobs expected.
# Tests + Formatting
Tests that previously chose to use `nu-command` for their scope will
still use `nu-cmd-lang` + `nu-command` (command list in the granularity
at the time)