Migrate last to engine-p (#3406)

* migrates last to engine-p

* removes unused import

* linter fix

* switch to as_usize()
This commit is contained in:
Alex Shadley 2021-05-11 20:59:08 -05:00 committed by GitHub
parent 311c0e3f50
commit 3795c2a39d
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@ -2,15 +2,9 @@ use crate::prelude::*;
use nu_engine::WholeStreamCommand;
use nu_errors::ShellError;
use nu_protocol::{Signature, SyntaxShape, UntaggedValue, Value};
use nu_source::Tagged;
pub struct Last;
#[derive(Deserialize)]
pub struct LastArgs {
rows: Option<Tagged<u64>>,
}
impl WholeStreamCommand for Last {
fn name(&self) -> &str {
"last"
@ -28,7 +22,7 @@ impl WholeStreamCommand for Last {
"Show only the last number of rows."
}
fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
last(args)
}
@ -52,12 +46,13 @@ impl WholeStreamCommand for Last {
}
}
fn last(args: CommandArgs) -> Result<ActionStream, ShellError> {
let (LastArgs { rows }, input) = args.process()?;
let v: Vec<_> = input.into_vec();
fn last(args: CommandArgs) -> Result<OutputStream, ShellError> {
let args = args.evaluate_once()?;
let rows = args.nth(0).cloned();
let v: Vec<_> = args.input.into_vec();
let end_rows_desired = if let Some(quantity) = rows {
*quantity as usize
quantity.as_usize()?
} else {
1
};
@ -70,7 +65,7 @@ fn last(args: CommandArgs) -> Result<ActionStream, ShellError> {
let iter = v.into_iter().skip(beginning_rows_to_skip);
Ok((iter).to_action_stream())
Ok(OutputStream::from_stream(iter))
}
#[cfg(test)]