nushell/crates/nu-cli/src/util.rs

use std::io::Write;

use nu_protocol::{
    ast::Call,
    engine::{EngineState, Stack},
    PipelineData, ShellError, Span, Value,
};

pub fn print_pipeline_data(
    input: PipelineData,
    engine_state: &EngineState,
    stack: &mut Stack,
) -> Result<(), ShellError> {
    // If the table function is in the declarations, then we can use it
    // to create the table value that will be printed in the terminal

    let config = stack.get_config().unwrap_or_default();

    let stdout = std::io::stdout();

    if let PipelineData::ExternalStream {
        stdout: stream,
        exit_code,
        ..
    } = input
    {
        if let Some(stream) = stream {
            for s in stream {
                let _ = stdout.lock().write_all(s?.as_binary()?);
            }
        }

        // Make sure everything has finished
        if let Some(exit_code) = exit_code {
            let _: Vec<_> = exit_code.into_iter().collect();
        }

        return Ok(());
    }

    match engine_state.find_decl("table".as_bytes()) {
        Some(decl_id) => {
            let table = engine_state.get_decl(decl_id).run(
                engine_state,
                stack,
                &Call::new(Span::new(0, 0)),
                input,
            )?;

            for item in table {
                let stdout = std::io::stdout();

                if let Value::Error { error } = item {
                    return Err(error);
                }

                let mut out = item.into_string("\n", &config);
                out.push('\n');

                match stdout.lock().write_all(out.as_bytes()) {
                    Ok(_) => (),
                    Err(err) => eprintln!("{}", err),
                };
            }
        }
        None => {
            for item in input {
                let stdout = std::io::stdout();

                if let Value::Error { error } = item {
                    return Err(error);
                }

                let mut out = item.into_string("\n", &config);
                out.push('\n');

                match stdout.lock().write_all(out.as_bytes()) {
                    Ok(_) => (),
                    Err(err) => eprintln!("{}", err),
                };
            }
        }
    };

    Ok(())
}