forked from extern/nushell
522a828687
* Refactor InputStream and affected commands. First, making `values` private and leaning on the `Stream` implementation makes consumes of `InputStream` less likely to have to change in the future, if we change what an `InputStream` is internally. Second, we're dropping `Option<InputStream>` as the input to pipelines, internals, and externals. Instead, `InputStream.is_empty` can be used to check for "emptiness". Empty streams are typically only ever used as the first input to a pipeline. * Add run_external internal command. We want to push external commands closer to internal commands, eventually eliminating the concept of "external" completely. This means we can consolidate a couple of things: - Variable evaluation (for example, `$it`, `$nu`, alias vars) - Behaviour of whole stream vs per-item external execution It should also make it easier for us to start introducing argument signatures for external commands, * Update run_external.rs * Update run_external.rs * Update run_external.rs * Update run_external.rs Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
70 lines
1.6 KiB
Rust
70 lines
1.6 KiB
Rust
use crate::commands::WholeStreamCommand;
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use crate::context::CommandRegistry;
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use crate::prelude::*;
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use nu_errors::ShellError;
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use nu_protocol::{ReturnSuccess, ReturnValue, Signature, SyntaxShape, Value};
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use nu_source::Tagged;
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use rand::seq::SliceRandom;
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use rand::thread_rng;
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pub struct Shuffle;
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#[derive(Deserialize)]
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pub struct Arguments {
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#[serde(rename = "num")]
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limit: Option<Tagged<u64>>,
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}
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impl WholeStreamCommand for Shuffle {
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fn name(&self) -> &str {
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"shuffle"
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}
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fn signature(&self) -> Signature {
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Signature::build("shuffle").named(
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"num",
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SyntaxShape::Int,
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"Limit `num` number of rows",
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Some('n'),
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)
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}
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fn usage(&self) -> &str {
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"Shuffle rows randomly."
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}
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fn run(
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&self,
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args: CommandArgs,
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registry: &CommandRegistry,
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) -> Result<OutputStream, ShellError> {
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args.process(registry, shuffle)?.run()
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}
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}
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fn shuffle(
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Arguments { limit }: Arguments,
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RunnableContext { input, .. }: RunnableContext,
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) -> Result<OutputStream, ShellError> {
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let stream = async_stream! {
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let mut values: Vec<Value> = input.collect().await;
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let out = if let Some(n) = limit {
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let (shuffled, _) = values.partial_shuffle(&mut thread_rng(), *n as usize);
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shuffled.to_vec()
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} else {
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values.shuffle(&mut thread_rng());
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values.clone()
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};
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for val in out.into_iter() {
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yield ReturnSuccess::value(val);
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}
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};
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let stream: BoxStream<'static, ReturnValue> = stream.boxed();
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Ok(stream.to_output_stream())
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}
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