pipa-lang 1.0.0-alpha.1

A tiny template language
Documentation
// SPDX-FileCopyrightText: Copyright 2026 olav@occy.org
// SPDX-License-Identifier: MPL-2.0

use crate::lang::adapter::Adapter;
use crate::lang::args::eval_unary_arg;
use crate::lang::args::take_thunk_arg;
use crate::lang::args::thunk_as_pipe;
use crate::lang::arity::Arity;
use crate::lang::arity::assert_func_arity;
use crate::lang::error::Error;
use crate::lang::eval::eval_node_list;
use crate::lang::machine::Machine;
use crate::lang::node::Node;
use crate::value::Value;
use crate::value::list::List;
use crate::value::map::Map;

pub(crate) fn map(
    adapter: &impl Adapter,
    machine: &mut Machine<'_>,
    stdin: Option<&Value>,
    mut node: Node,
) -> Result<Value, Error> {
    assert_func_arity(adapter, machine, stdin, &node, &Arity::new(2))?;

    let thunk = take_thunk_arg(adapter, machine, &mut node)?;
    let thunk = thunk_as_pipe(adapter, machine, thunk)?;
    let value = eval_unary_arg(adapter, machine, stdin, node)?;
    let value = value.unwrap_or_default();

    let mut call = |v: &Value| eval_node_list(adapter, machine, Some(v), thunk.clone());

    let value = match value {
        v @ Value::Bytes(_) => call(&v)?,
        Value::List(v) => Some(Value::from(
            v.into_iter()
                .map(|v| call(&v))
                .collect::<Result<Vec<_>, _>>()?
                .into_iter()
                .flatten()
                .collect::<List>(),
        )),
        Value::Map(v) => Some(Value::from(
            v.into_iter()
                .map(|(k, v)| call(&v).map(|v| (k, v)))
                .collect::<Result<Vec<_>, _>>()?
                .into_iter()
                .collect::<Map>(),
        )),
    };

    Ok(value.unwrap_or_default())
}