use crate::lang::adapter::Adapter;
use crate::lang::args::eval_args;
use crate::lang::arity::Arity;
use crate::lang::arity::assert_func_arity;
use crate::lang::error::Error;
use crate::lang::machine::Machine;
use crate::lang::node::Node;
use crate::value::Value;
use itertools::Itertools;
pub(crate) fn join(
adapter: &impl Adapter,
machine: &mut Machine<'_>,
stdin: Option<&Value>,
node: Node,
) -> Result<Value, Error> {
assert_func_arity(adapter, machine, stdin, &node, &Arity::minmax(1, 2))?;
let mut node = eval_args(adapter, machine, stdin, node)?;
let value = node.pop().flatten().unwrap_or_default();
let sep = node.pop().flatten().unwrap_or_default().join();
let iter = value.into_list().into_iter().map(Value::join);
let iter = Itertools::intersperse(iter, sep).flatten();
Ok(iter.collect::<Vec<u8>>().into())
}