use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Type,
};
use rand::prelude::SliceRandom;
use rand::thread_rng;
#[derive(Clone)]
pub struct Shuffle;
impl Command for Shuffle {
fn name(&self) -> &str {
"shuffle"
}
fn signature(&self) -> nu_protocol::Signature {
Signature::build("shuffle")
.input_output_types(vec![(
Type::List(Box::new(Type::Any)),
Type::List(Box::new(Type::Any)),
)])
.category(Category::Filters)
}
fn usage(&self) -> &str {
"Shuffle rows randomly."
}
fn run(
&self,
engine_state: &EngineState,
_stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let metadata = input.metadata();
let mut v: Vec<_> = input.into_iter_strict(call.head)?.collect();
v.shuffle(&mut thread_rng());
let iter = v.into_iter();
Ok(iter
.into_pipeline_data(engine_state.ctrlc.clone())
.set_metadata(metadata))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Shuffle rows randomly (execute it several times and see the difference)",
example: r#"[[version patch]; [1.0.0 false] [3.0.1 true] [2.0.0 false]] | shuffle"#,
result: None,
}]
}
}