mirror of
https://github.com/nushell/nushell
synced 2024-12-27 05:23:11 +00:00
9cf2e873b5
[Context on Discord](https://discord.com/channels/601130461678272522/855947301380947968/1216517833312309419) # Description This is a significant breaking change to the plugin API, but one I think is worthwhile. @ayax79 mentioned on Discord that while trying to start on a dataframes plugin, he was a little disappointed that more wasn't provided in terms of code organization for commands, particularly since there are *a lot* of `dfr` commands. This change treats plugins more like miniatures of the engine, with dispatch of the command name being handled inherently, each command being its own type, and each having their own signature within the trait impl for the command type rather than having to find a way to centralize it all into one `Vec`. For the example plugins that have multiple commands, I definitely like how this looks a lot better. This encourages doing code organization the right way and feels very good. For the plugins that have only one command, it's just a little bit more boilerplate - but still worth it, in my opinion. The `Box<dyn PluginCommand<Plugin = Self>>` type in `commands()` is a little bit hairy, particularly for Rust beginners, but ultimately not so bad, and it gives the desired flexibility for shared state for a whole plugin + the individual commands. # User-Facing Changes Pretty big breaking change to plugin API, but probably one that's worth making. ```rust use nu_plugin::*; use nu_protocol::{PluginSignature, PipelineData, Type, Value}; struct LowercasePlugin; struct Lowercase; // Plugins can now have multiple commands impl PluginCommand for Lowercase { type Plugin = LowercasePlugin; // The signature lives with the command fn signature(&self) -> PluginSignature { PluginSignature::build("lowercase") .usage("Convert each string in a stream to lowercase") .input_output_type(Type::List(Type::String.into()), Type::List(Type::String.into())) } // We also provide SimplePluginCommand which operates on Value like before fn run( &self, plugin: &LowercasePlugin, engine: &EngineInterface, call: &EvaluatedCall, input: PipelineData, ) -> Result<PipelineData, LabeledError> { let span = call.head; Ok(input.map(move |value| { value.as_str() .map(|string| Value::string(string.to_lowercase(), span)) // Errors in a stream should be returned as values. .unwrap_or_else(|err| Value::error(err, span)) }, None)?) } } // Plugin now just has a list of commands, and the custom value op stuff still goes here impl Plugin for LowercasePlugin { fn commands(&self) -> Vec<Box<dyn PluginCommand<Plugin=Self>>> { vec![Box::new(Lowercase)] } } fn main() { serve_plugin(&LowercasePlugin{}, MsgPackSerializer) } ``` Time this however you like - we're already breaking stuff for 0.92, so it might be good to do it now, but if it feels like a lot all at once, it could wait. # Tests + Formatting - 🟢 `toolkit fmt` - 🟢 `toolkit clippy` - 🟢 `toolkit test` - 🟢 `toolkit test stdlib` # After Submitting - [ ] Update examples in the book - [x] Fix #12088 to match - this change would actually simplify it a lot, because the methods are currently just duplicated between `Plugin` and `StreamingPlugin`, but they only need to be on `Plugin` with this change |
||
|---|---|---|
| .. | ||
| nu-cli | ||
| nu-cmd-base | ||
| nu-cmd-dataframe | ||
| nu-cmd-extra | ||
| nu-cmd-lang | ||
| nu-color-config | ||
| nu-command | ||
| nu-engine | ||
| nu-explore | ||
| nu-glob | ||
| nu-json | ||
| nu-lsp | ||
| nu-parser | ||
| nu-path | ||
| nu-plugin | ||
| nu-pretty-hex | ||
| nu-protocol | ||
| nu-std | ||
| nu-system | ||
| nu-table | ||
| nu-term-grid | ||
| nu-test-support | ||
| nu-utils | ||
| nu_plugin_custom_values | ||
| nu_plugin_example | ||
| nu_plugin_formats | ||
| nu_plugin_gstat | ||
| nu_plugin_inc | ||
| nu_plugin_python | ||
| nu_plugin_query | ||
| nu_plugin_stream_example | ||
| README.md | ||
Nushell core libraries and plugins
These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.
Foundational libraries are split into two kinds of crates:
- Core crates - those crates that work together to build the Nushell language engine
- Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.
Plugins are likewise also split into two types:
- Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
- Extra plugins - these plugins run a wide range of different capabilities like working with different file types, charting, viewing binary data, and more.