104 lines
2.9 KiB
Rust
104 lines
2.9 KiB
Rust
|
use crate::any::{Any, Dynamic};
|
||
|
|
|
||
|
|
/// A type containing information about current scope.
|
||
|
|
/// Useful for keeping state between `Engine` runs
|
||
|
|
///
|
||
|
|
/// ```rust
|
||
|
|
/// use rhai::{Engine, Scope};
|
||
|
|
///
|
||
|
|
/// let mut engine = Engine::new();
|
||
|
|
/// let mut my_scope = Scope::new();
|
||
|
|
///
|
||
|
|
/// assert!(engine.eval_with_scope::<()>(&mut my_scope, "let x = 5;").is_ok());
|
||
|
|
/// assert_eq!(engine.eval_with_scope::<i64>(&mut my_scope, "x + 1").unwrap(), 6);
|
||
|
|
/// ```
|
||
|
|
///
|
||
|
|
/// Between runs, `Engine` only remembers functions when not using own `Scope`.
|
||
|
|
|
||
|
|
pub struct Scope(Vec<(String, Dynamic)>);
|
||
|
|
|
||
|
|
impl Scope {
|
||
|
|
/// Create a new Scope.
|
||
|
|
pub fn new() -> Self {
|
||
|
|
Self(Vec::new())
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Empty the Scope.
|
||
|
|
pub fn clear(&mut self) {
|
||
|
|
self.0.clear();
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get the number of variables inside the Scope.
|
||
|
|
pub fn len(&self) -> usize {
|
||
|
|
self.0.len()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Add (push) a new variable to the Scope.
|
||
|
|
pub fn push<T: Any>(&mut self, key: String, value: T) {
|
||
|
|
self.0.push((key, Box::new(value)));
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Add (push) a new variable to the Scope.
|
||
|
|
pub(crate) fn push_dynamic(&mut self, key: String, value: Dynamic) {
|
||
|
|
self.0.push((key, value));
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Remove (pop) the last variable from the Scope.
|
||
|
|
pub fn pop(&mut self) -> Option<(String, Dynamic)> {
|
||
|
|
self.0.pop()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Truncate (rewind) the Scope to a previous size.
|
||
|
|
pub fn rewind(&mut self, size: usize) {
|
||
|
|
self.0.truncate(size);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Find a variable in the Scope, starting from the last.
|
||
|
|
pub fn get(&self, key: &str) -> Option<(usize, String, Dynamic)> {
|
||
|
|
self.0
|
||
|
|
.iter()
|
||
|
|
.enumerate()
|
||
|
|
.rev()
|
||
|
|
.find(|(_, (n, _))| n == key)
|
||
|
|
.map(|(i, (n, v))| (i, n.clone(), v.clone()))
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get the value of a variable in the Scope, starting from the last.
|
||
|
|
pub fn get_value<T: Any + Clone>(&self, key: &str) -> Option<T> {
|
||
|
|
self.0
|
||
|
|
.iter()
|
||
|
|
.enumerate()
|
||
|
|
.rev()
|
||
|
|
.find(|(_, (n, _))| n == key)
|
||
|
|
.map(|(_, (_, v))| v.downcast_ref() as Option<&T>)
|
||
|
|
.map(|v| v.unwrap().clone())
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get a mutable reference to a variable in the Scope.
|
||
|
|
pub(crate) fn get_mut(&mut self, key: &str, index: usize) -> &mut Dynamic {
|
||
|
|
let entry = self.0.get_mut(index).expect("invalid index in Scope");
|
||
|
|
|
||
|
|
if entry.0 != key {
|
||
|
|
panic!("incorrect key at Scope entry");
|
||
|
|
}
|
||
|
|
|
||
|
|
&mut entry.1
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get an iterator to variables in the Scope.
|
||
|
|
pub fn iter(&self) -> std::slice::Iter<(String, Dynamic)> {
|
||
|
|
self.0.iter()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get a mutable iterator to variables in the Scope.
|
||
|
|
pub(crate) fn iter_mut(&mut self) -> std::slice::IterMut<(String, Dynamic)> {
|
||
|
|
self.0.iter_mut()
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl std::iter::Extend<(String, Dynamic)> for Scope {
|
||
|
|
fn extend<T: IntoIterator<Item = (String, Dynamic)>>(&mut self, iter: T) {
|
||
|
|
self.0.extend(iter);
|
||
|
|
}
|
||
|
|
}
|