01d30a416b
# Description
This is something that was discussed in the core team meeting last
Wednesday. @ayax79 is building `nu-plugin-polars` with all of the
dataframe commands into a plugin, and there are a lot of them, so it
would help to make the API more similar. At the same time, I think the
`Command` API is just better anyway. I don't think the difference is
justified, and the types for core commands have the benefit of requiring
less `.into()` because they often don't own their data
- Broke `signature()` up into `name()`, `usage()`, `extra_usage()`,
`search_terms()`, `examples()`
- `signature()` returns `nu_protocol::Signature`
- `examples()` returns `Vec<nu_protocol::Example>`
- `PluginSignature` and `PluginExample` no longer need to be used by
plugin developers
# User-Facing Changes
Breaking API for plugins yet again 😄
108 lines
2.9 KiB
Rust
108 lines
2.9 KiB
Rust
use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand};
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use nu_protocol::{Category, Example, LabeledError, PipelineData, Signature, Span, Type, Value};
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use crate::ExamplePlugin;
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/// `<list> | example sum`
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pub struct Sum;
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impl PluginCommand for Sum {
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type Plugin = ExamplePlugin;
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fn name(&self) -> &str {
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"example sum"
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}
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fn usage(&self) -> &str {
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"Example stream consumer for a list of values"
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}
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fn signature(&self) -> Signature {
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Signature::build(self.name())
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.input_output_types(vec![
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(Type::List(Type::Int.into()), Type::Int),
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(Type::List(Type::Float.into()), Type::Float),
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])
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.category(Category::Experimental)
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}
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fn search_terms(&self) -> Vec<&str> {
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vec!["example"]
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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example: "example seq 1 5 | example sum",
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description: "sum values from 1 to 5",
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result: Some(Value::test_int(15)),
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}]
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}
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fn run(
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&self,
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_plugin: &ExamplePlugin,
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_engine: &EngineInterface,
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call: &EvaluatedCall,
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input: PipelineData,
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) -> Result<PipelineData, LabeledError> {
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let mut acc = IntOrFloat::Int(0);
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for value in input {
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if let Ok(n) = value.as_i64() {
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acc.add_i64(n);
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} else if let Ok(n) = value.as_f64() {
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acc.add_f64(n);
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} else {
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return Err(LabeledError::new("Sum only accepts ints and floats")
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.with_label(format!("found {} in input", value.get_type()), value.span())
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.with_label("can't be used here", call.head));
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}
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}
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Ok(PipelineData::Value(acc.to_value(call.head), None))
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}
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}
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/// Accumulates numbers into either an int or a float. Changes type to float on the first
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/// float received.
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#[derive(Clone, Copy)]
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enum IntOrFloat {
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Int(i64),
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Float(f64),
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}
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impl IntOrFloat {
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pub(crate) fn add_i64(&mut self, n: i64) {
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match self {
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IntOrFloat::Int(ref mut v) => {
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*v += n;
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}
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IntOrFloat::Float(ref mut v) => {
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*v += n as f64;
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}
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}
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}
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pub(crate) fn add_f64(&mut self, n: f64) {
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match self {
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IntOrFloat::Int(v) => {
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*self = IntOrFloat::Float(*v as f64 + n);
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}
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IntOrFloat::Float(ref mut v) => {
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*v += n;
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}
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}
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}
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pub(crate) fn to_value(self, span: Span) -> Value {
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match self {
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IntOrFloat::Int(v) => Value::int(v, span),
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IntOrFloat::Float(v) => Value::float(v, span),
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}
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}
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}
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#[test]
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fn test_examples() -> Result<(), nu_protocol::ShellError> {
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use nu_plugin_test_support::PluginTest;
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PluginTest::new("example", ExamplePlugin.into())?.test_command_examples(&Sum)
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}
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