# Description
The meaning of the word usage is specific to describing how a command
function is *used* and not a synonym for general description. Usage can
be used to describe the SYNOPSIS or EXAMPLES sections of a man page
where the permitted argument combinations are shown or example *uses*
are given.
Let's not confuse people and call it what it is a description.
Our `help` command already creates its own *Usage* section based on the
available arguments and doesn't refer to the description with usage.
# User-Facing Changes
`help commands` and `scope commands` will now use `description` or
`extra_description`
`usage`-> `description`
`extra_usage` -> `extra_description`
Breaking change in the plugin protocol:
In the signature record communicated with the engine.
`usage`-> `description`
`extra_usage` -> `extra_description`
The same rename also takes place for the methods on
`SimplePluginCommand` and `PluginCommand`
# Tests + Formatting
- Updated plugin protocol specific changes
# After Submitting
- [ ] update plugin protocol doc
# Description
Adds functionality to the plugin interface to support calling internal
commands from plugins. For example, using `view ir --json`:
```rust
let closure: Value = call.req(0)?;
let Some(decl_id) = engine.find_decl("view ir")? else {
return Err(LabeledError::new("`view ir` not found"));
};
let ir_json = engine.call_decl(
decl_id,
EvaluatedCall::new(call.head)
.with_named("json".into_spanned(call.head), Value::bool(true, call.head))
.with_positional(closure),
PipelineData::Empty,
true,
false,
)?.into_value()?.into_string()?;
let ir = serde_json::from_value(&ir_json);
// ...
```
# User-Facing Changes
Plugin developers can now use `EngineInterface::find_decl()` and
`call_decl()` to call internal commands, which could be handy for
formatters like `to csv` or `to nuon`, or for reflection commands that
help gain insight into the engine.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] release notes
- [ ] update plugin protocol documentation: `FindDecl`, `CallDecl`
engine calls; `Identifier` engine call response
