use std::cell::RefCell;
use std::rc::Rc;
#[derive(Debug, Clone, Eq, PartialEq)]
pub(crate) enum ContextItem {
Class,
Module,
Sclass,
Def,
Defs,
Block,
Lambda,
}
#[derive(Debug, Clone, Default)]
pub(crate) struct Context {
pub(crate) stack: Rc<RefCell<Vec<ContextItem>>>,
}
impl Context {
pub(crate) fn new() -> Self {
Self {
stack: Rc::new(RefCell::new(vec![])),
}
}
fn push(&self, item: ContextItem) {
self.stack.borrow_mut().push(item);
}
pub(crate) fn push_class(&self) {
self.push(ContextItem::Class)
}
pub(crate) fn push_module(&self) {
self.push(ContextItem::Module)
}
pub(crate) fn push_sclass(&self) {
self.push(ContextItem::Sclass)
}
pub(crate) fn push_def(&self) {
self.push(ContextItem::Def)
}
pub(crate) fn push_defs(&self) {
self.push(ContextItem::Defs)
}
pub(crate) fn push_block(&self) {
self.push(ContextItem::Block)
}
pub(crate) fn push_lambda(&self) {
self.push(ContextItem::Lambda)
}
pub(crate) fn pop(&self) {
self.stack.borrow_mut().pop();
}
fn is_in(&self, item: ContextItem) -> bool {
self.stack.borrow().last() == Some(&item)
}
pub(crate) fn is_in_class(&self) -> bool {
self.is_in(ContextItem::Class)
}
#[allow(dead_code)]
pub(crate) fn is_in_module(&self) -> bool {
self.is_in(ContextItem::Module)
}
#[allow(dead_code)]
pub(crate) fn is_in_sclass(&self) -> bool {
self.is_in(ContextItem::Sclass)
}
pub(crate) fn is_in_def(&self) -> bool {
self.is_in(ContextItem::Def)
}
#[allow(dead_code)]
pub(crate) fn is_in_defs(&self) -> bool {
self.is_in(ContextItem::Defs)
}
#[allow(dead_code)]
pub(crate) fn is_in_block(&self) -> bool {
self.is_in(ContextItem::Block)
}
#[allow(dead_code)]
pub(crate) fn is_in_lambda(&self) -> bool {
self.is_in(ContextItem::Lambda)
}
#[allow(dead_code)]
pub(crate) fn reset(&self) {
self.stack.borrow_mut().clear()
}
#[allow(dead_code)]
pub(crate) fn is_indirectly_in_def(&self) -> bool {
let stack = self.stack.borrow();
stack.contains(&ContextItem::Def) || stack.contains(&ContextItem::Defs)
}
pub(crate) fn is_class_definition_allowed(&self) -> bool {
let stack = self.stack.borrow();
let def_index: Option<usize> = stack
.iter()
.rev()
.position(|i| *i == ContextItem::Def || *i == ContextItem::Defs);
let sclass_index: Option<usize> =
stack.iter().rev().position(|i| *i == ContextItem::Sclass);
match (def_index, sclass_index) {
(None, _) => true,
(Some(_), None) => false,
(Some(def_index), Some(sclass_index)) => sclass_index < def_index,
}
}
pub(crate) fn is_module_definition_allowed(&self) -> bool {
self.is_class_definition_allowed()
}
pub(crate) fn is_dynamic_const_definition_allowed(&self) -> bool {
self.is_class_definition_allowed()
}
pub(crate) fn is_in_dynamic_block(&self) -> bool {
self.is_in(ContextItem::Block) || self.is_in(ContextItem::Lambda)
}
pub(crate) fn inner_clone(&self) -> Vec<ContextItem> {
self.stack.borrow().clone()
}
}