ksl 0.1.30

//! # ksl::builtin::consume
//!
//! Built-in function `Consume`.

use crate::{Environment, builtin::ERR_SYMBOL, eval::apply::eval_apply, value::Value};

pub(crate) fn builtin(args: &[Value], env: Environment) -> Result<Value, std::sync::Arc<str>> {
    if let [thread] = args {
        match eval_apply(thread, env)? {
            Value::Thread(handler) => {
                let mut guard = handler.lock();
                let thread_body = guard.take();
                match thread_body {
                    Some(handle) => handle.join().map_err(|_| {
                        std::sync::Arc::from(concat!(
                            "Error[ksl::builtin::Consume]: ",
                            "Failed to join the thread."
                        ))
                    })?,
                    None => Ok(Value::List(std::sync::Arc::new([
                        ERR_SYMBOL.clone(),
                        Value::String(std::sync::Arc::from("Removed thread.")),
                    ]))),
                }
            }

            e => Err(std::sync::Arc::from(format!(
                concat!("Error[ksl::builtin::Consume]: ", "Unexpected value: `{}`."),
                e
            ))),
        }
    } else {
        Err(std::sync::Arc::from(format!(
            concat!(
                "Error[ksl::builtin::Consume]: ",
                "Expected 1 parameter, but {} were passed."
            ),
            args.len()
        )))
    }
}