nushell/crates/nu-cli/src/commands/what.rs

60 lines
1.4 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use nu_errors::ShellError;
use nu_protocol::{ReturnSuccess, ReturnValue, Signature, UntaggedValue};
pub struct What;
#[derive(Deserialize)]
pub struct WhatArgs {}
impl WholeStreamCommand for What {
fn name(&self) -> &str {
"describe"
}
fn signature(&self) -> Signature {
Signature::build("describe")
}
fn usage(&self) -> &str {
"Describes the objects in the stream."
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
// args.process(registry, what)?.run()
what(args, registry)
}
}
pub fn what(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
let stream = async_stream! {
let mut input = args.input;
while let Some(row) = input.next().await {
let name = value::format_type(&row, 100);
yield ReturnSuccess::value(UntaggedValue::string(name).into_value(Tag::unknown_anchor(row.tag.span)));
}
};
let stream: BoxStream<'static, ReturnValue> = stream.boxed();
Ok(OutputStream::from(stream))
}
#[cfg(test)]
mod tests {
use super::What;
#[test]
fn examples_work_as_expected() {
use crate::examples::test as test_examples;
test_examples(What {})
}
}