ksl 0.1.30

KSL core library and interpreter
Documentation
//! # ksl::builtin::object
//!
//! Built-in function `Object`.

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

pub(crate) fn builtin(args: &[Value], env: Environment) -> Result<Value, std::sync::Arc<str>> {
    if let [sym] = args {
        match sym {
            Value::Symbol(type_sym) => Ok(Value::Object(type_sym.clone(), Box::default())),
            e => Err(std::sync::Arc::from(format!(
                concat!(
                    "Error[ksl::builtin::Object]: ",
                    "Expected a symbol as type tag, but got: `{}`."
                ),
                e
            ))),
        }
    } else if let [sym, pairs] = args {
        match (sym, eval_apply(pairs, env)?) {
            (Value::Symbol(type_sym), Value::List(assocs)) => {
                let mut dict = Dict::with_capacity_and_hasher(assocs.len(), rustc_hash::FxBuildHasher);
                for assoc in assocs.iter() {
                    match assoc {
                        Value::List(kv) => match kv.as_ref() {
                            [Value::Atom(key), e] => {
                                let _ = dict.insert(key.clone(), std::sync::Arc::new(e.clone()));
                            }
                            [e, _] => {
                                return Err(std::sync::Arc::from(format!(
                                    concat!(
                                        "Error[ksl::builtin::Object]: ",
                                        "Expected an atom as key, but got `{}`."
                                    ),
                                    e
                                )));
                            }
                            _ => {
                                return Err(std::sync::Arc::from(format!(
                                    concat!(
                                        "Error[ksl::builtin::Object]: ",
                                        "Expected a list with length 2, but got `{}`."
                                    ),
                                    kv.len()
                                )));
                            }
                        },
                        e => {
                            return Err(std::sync::Arc::from(format!(
                                concat!(
                                    "Error[ksl::builtin::Object]: ",
                                    "Expected a list, but got: `{}`."
                                ),
                                e
                            )));
                        }
                    }
                }
                Ok(Value::Object(type_sym.clone(), Box::new(dict)))
            }
            (Value::Symbol(_), e) => Err(std::sync::Arc::from(format!(
                concat!(
                    "Error[ksl::builtin::Object]: ",
                    "Expected a list, but got: `{}`."
                ),
                e
            ))),
            (e, _) => Err(std::sync::Arc::from(format!(
                concat!(
                    "Error[ksl::builtin::Object]: ",
                    "Expected a symbol as type tag, but got: `{}`."
                ),
                e
            ))),
        }
    } else {
        Err(std::sync::Arc::from(format!(
            concat!(
                "Error[ksl::builtin::Object]: ",
                "Expected 1 or 2 parameters, but {} were passed."
            ),
            args.len()
        )))
    }
}