xs/nu/commands/
last_command.rs

1use nu_engine::CallExt;
2use nu_protocol::engine::{Call, Command, EngineState, Stack};
3use nu_protocol::{Category, PipelineData, ShellError, Signature, SyntaxShape, Type};
4
5use crate::nu::util;
6use crate::store::Store;
7
8#[derive(Clone)]
9pub struct LastCommand {
10    store: Store,
11}
12
13impl LastCommand {
14    pub fn new(store: Store) -> Self {
15        Self { store }
16    }
17}
18
19impl Command for LastCommand {
20    fn name(&self) -> &str {
21        ".last"
22    }
23
24    fn signature(&self) -> Signature {
25        Signature::build(".last")
26            .input_output_types(vec![(Type::Nothing, Type::Any)])
27            .required(
28                "topic",
29                SyntaxShape::String,
30                "topic to get most recent frame from",
31            )
32            .category(Category::Experimental)
33    }
34
35    fn description(&self) -> &str {
36        "get the most recent frame for a topic"
37    }
38
39    fn run(
40        &self,
41        engine_state: &EngineState,
42        stack: &mut Stack,
43        call: &Call,
44        _input: PipelineData,
45    ) -> Result<PipelineData, ShellError> {
46        let topic: String = call.req(engine_state, stack, 0)?;
47        let span = call.head;
48
49        if let Some(frame) = self.store.last(&topic) {
50            Ok(PipelineData::Value(
51                util::frame_to_value(&frame, span),
52                None,
53            ))
54        } else {
55            Ok(PipelineData::Empty)
56        }
57    }
58}
xs/nu/commands/last_command.rs

xs/nu/commands/
last_command.rs
