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//! Module that defines the [`Scope`] type representing a function call-stack scope.
use super::dynamic::{AccessMode, Variant};
use crate::{Dynamic, Identifier, ImmutableString, StaticVec, ThinVec};
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
use std::{
fmt, iter,
iter::{Extend, FromIterator},
marker::PhantomData,
};
/// Minimum number of entries in the [`Scope`] to avoid reallocations.
pub const MIN_SCOPE_ENTRIES: usize = 8;
/// Type containing information about the current scope. Useful for keeping state between
/// [`Engine`][crate::Engine] evaluation runs.
///
/// # Lifetime
///
/// Currently the lifetime parameter is not used, but it is not guaranteed to remain unused for
/// future versions. Until then, `'static` can be used.
///
/// # Thread Safety
///
/// Currently, [`Scope`] is neither [`Send`] nor [`Sync`]. Turn on the `sync` feature to make it
/// [`Send`] `+` [`Sync`].
///
/// # Example
///
/// ```
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, Scope};
///
/// let engine = Engine::new();
/// let mut my_scope = Scope::new();
///
/// my_scope.push("z", 40_i64);
///
/// engine.run_with_scope(&mut my_scope, "let x = z + 1; z = 0;")?;
///
/// let result: i64 = engine.eval_with_scope(&mut my_scope, "x + 1")?;
///
/// assert_eq!(result, 42);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 41);
/// assert_eq!(my_scope.get_value::<i64>("z").expect("z should exist"), 0);
/// # Ok(())
/// # }
/// ```
///
/// When searching for entries, newly-added entries are found before similarly-named but older
/// entries, allowing for automatic _shadowing_.
//
// # Implementation Notes
//
// [`Scope`] is implemented as three arrays. Two (`values` and `names`) are of exactly the same
// length. That's because in the vast majority of cases the name is NOT used to look up a variable.
// Variable lookup is usually via direct indexing, by-passing the name altogether.
//
// [`Dynamic`] is reasonably small so packing it tightly improves cache performance.
#[derive(Debug, Hash, Default)]
pub struct Scope<'a> {
/// Current value of the entry.
values: ThinVec<Dynamic>,
/// Name of the entry.
names: ThinVec<ImmutableString>,
/// Aliases of the entry.
///
/// This `Vec` is not filled until needed because aliases are used rarely
/// (only for `export` statements).
aliases: ThinVec<StaticVec<ImmutableString>>,
/// Phantom to keep the lifetime parameter in order not to break existing code.
dummy: PhantomData<&'a ()>,
}
impl fmt::Display for Scope<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for (i, (name, constant, value)) in self.iter_inner().enumerate() {
writeln!(
f,
"[{}] {}{} = {:?}",
i + 1,
if constant { "const " } else { "" },
name,
value,
)?;
}
Ok(())
}
}
impl Clone for Scope<'_> {
#[inline]
fn clone(&self) -> Self {
Self {
values: self
.values
.iter()
.map(|v| {
// Also copy the value's access mode (otherwise will turn to read-write)
let mut v2 = v.clone();
v2.set_access_mode(v.access_mode());
v2
})
.collect(),
names: self.names.clone(),
aliases: self.aliases.clone(),
dummy: self.dummy,
}
}
}
impl IntoIterator for Scope<'_> {
type Item = (String, Dynamic, Vec<ImmutableString>);
type IntoIter = Box<dyn Iterator<Item = Self::Item>>;
#[must_use]
fn into_iter(self) -> Self::IntoIter {
Box::new(
self.values
.into_iter()
.zip(
self.names.into_iter().zip(
self.aliases
.into_iter()
.map(|a| a.to_vec())
.chain(iter::repeat(Vec::new())),
),
)
.map(|(value, (name, alias))| (name.to_string(), value, alias)),
)
}
}
impl<'a> IntoIterator for &'a Scope<'_> {
type Item = (&'a str, &'a Dynamic, &'a [ImmutableString]);
type IntoIter = Box<dyn Iterator<Item = Self::Item> + 'a>;
#[must_use]
fn into_iter(self) -> Self::IntoIter {
Box::new(
self.values
.iter()
.zip(
self.names.iter().zip(
self.aliases
.iter()
.map(<_>::as_ref)
.chain(iter::repeat(&[][..])),
),
)
.map(|(value, (name, alias))| (name.as_str(), value, alias)),
)
}
}
impl Scope<'_> {
/// Create a new [`Scope`].
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
#[must_use]
pub fn new() -> Self {
Self {
values: ThinVec::new(),
names: ThinVec::new(),
aliases: ThinVec::new(),
dummy: PhantomData,
}
}
/// Create a new [`Scope`] with a particular capacity.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::with_capacity(10);
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
#[must_use]
pub fn with_capacity(capacity: usize) -> Self {
Self {
values: ThinVec::with_capacity(capacity),
names: ThinVec::with_capacity(capacity),
aliases: ThinVec::new(),
dummy: PhantomData,
}
}
/// Empty the [`Scope`].
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert!(my_scope.contains("x"));
/// assert_eq!(my_scope.len(), 1);
/// assert!(!my_scope.is_empty());
///
/// my_scope.clear();
/// assert!(!my_scope.contains("x"));
/// assert_eq!(my_scope.len(), 0);
/// assert!(my_scope.is_empty());
/// ```
#[inline(always)]
pub fn clear(&mut self) -> &mut Self {
self.names.clear();
self.values.clear();
self.aliases.clear();
self
}
/// Get the number of entries inside the [`Scope`].
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
/// assert_eq!(my_scope.len(), 0);
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.len(), 1);
/// ```
#[inline(always)]
#[must_use]
pub fn len(&self) -> usize {
self.values.len()
}
/// Returns `true` if this [`Scope`] contains no variables.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
/// assert!(my_scope.is_empty());
///
/// my_scope.push("x", 42_i64);
/// assert!(!my_scope.is_empty());
/// ```
#[inline(always)]
#[must_use]
pub fn is_empty(&self) -> bool {
self.values.is_empty()
}
/// Add (push) a new entry to the [`Scope`].
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
pub fn push(&mut self, name: impl Into<Identifier>, value: impl Variant + Clone) -> &mut Self {
self.push_entry(
name.into().into(),
AccessMode::ReadWrite,
Dynamic::from(value),
)
}
/// Add (push) a new [`Dynamic`] entry to the [`Scope`].
///
/// # Example
///
/// ```
/// use rhai::{Dynamic, Scope};
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push_dynamic("x", Dynamic::from(42_i64));
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
pub fn push_dynamic(&mut self, name: impl Into<Identifier>, value: Dynamic) -> &mut Self {
self.push_entry(name.into().into(), value.access_mode(), value)
}
/// Add (push) a new constant to the [`Scope`].
///
/// Constants are immutable and cannot be assigned to. Their values never change.
/// Constants propagation is a technique used to optimize an [`AST`][crate::AST].
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push_constant("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
pub fn push_constant(
&mut self,
name: impl Into<Identifier>,
value: impl Variant + Clone,
) -> &mut Self {
self.push_entry(
name.into().into(),
AccessMode::ReadOnly,
Dynamic::from(value),
)
}
/// Add (push) a new constant with a [`Dynamic`] value to the Scope.
///
/// Constants are immutable and cannot be assigned to. Their values never change.
/// Constants propagation is a technique used to optimize an [`AST`][crate::AST].
///
/// # Example
///
/// ```
/// use rhai::{Dynamic, Scope};
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push_constant_dynamic("x", Dynamic::from(42_i64));
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline(always)]
pub fn push_constant_dynamic(
&mut self,
name: impl Into<Identifier>,
value: Dynamic,
) -> &mut Self {
self.push_entry(name.into().into(), AccessMode::ReadOnly, value)
}
/// Add (push) a new entry with a [`Dynamic`] value to the [`Scope`].
#[inline]
pub(crate) fn push_entry(
&mut self,
name: ImmutableString,
access: AccessMode,
mut value: Dynamic,
) -> &mut Self {
if self.is_empty() {
self.names.reserve(MIN_SCOPE_ENTRIES);
self.values.reserve(MIN_SCOPE_ENTRIES);
}
self.names.push(name);
value.set_access_mode(access);
self.values.push(value);
self
}
/// Remove the last entry from the [`Scope`].
///
/// # Panics
///
/// Panics is the [`Scope`] is empty.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// my_scope.push("y", 123_i64);
/// assert!(my_scope.contains("x"));
/// assert!(my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 2);
///
/// my_scope.pop();
/// assert!(my_scope.contains("x"));
/// assert!(!my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 1);
///
/// my_scope.pop();
/// assert!(!my_scope.contains("x"));
/// assert!(!my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 0);
/// assert!(my_scope.is_empty());
/// ```
#[inline(always)]
pub fn pop(&mut self) -> &mut Self {
self.names
.pop()
.unwrap_or_else(|| panic!("`Scope` is empty"));
self.values.truncate(self.names.len());
self.aliases.truncate(self.names.len());
self
}
/// Remove the last entry from the [`Scope`] and return it.
#[inline(always)]
#[allow(dead_code)]
pub(crate) fn pop_entry(&mut self) -> Option<(ImmutableString, Dynamic, Vec<ImmutableString>)> {
self.values.pop().map(|value| {
(
self.names.pop().unwrap(),
value,
if self.aliases.len() > self.values.len() {
self.aliases.pop().unwrap().to_vec()
} else {
Vec::new()
},
)
})
}
/// Truncate (rewind) the [`Scope`] to a previous size.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// my_scope.push("y", 123_i64);
/// assert!(my_scope.contains("x"));
/// assert!(my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 2);
///
/// my_scope.rewind(1);
/// assert!(my_scope.contains("x"));
/// assert!(!my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 1);
///
/// my_scope.rewind(0);
/// assert!(!my_scope.contains("x"));
/// assert!(!my_scope.contains("y"));
/// assert_eq!(my_scope.len(), 0);
/// assert!(my_scope.is_empty());
/// ```
#[inline(always)]
pub fn rewind(&mut self, size: usize) -> &mut Self {
self.names.truncate(size);
self.values.truncate(size);
self.aliases.truncate(size);
self
}
/// Does the [`Scope`] contain the entry?
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert!(my_scope.contains("x"));
/// assert!(!my_scope.contains("y"));
/// ```
#[inline]
#[must_use]
pub fn contains(&self, name: &str) -> bool {
self.names.iter().any(|key| name == key)
}
/// Find an entry in the [`Scope`], starting from the last.
#[inline]
#[must_use]
pub(crate) fn search(&self, name: &str) -> Option<usize> {
self.names
.iter()
.rev() // Always search a Scope in reverse order
.position(|key| name == key)
.map(|i| self.len() - 1 - i)
}
/// Get the value of an entry in the [`Scope`], starting from the last.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// ```
#[inline]
#[must_use]
pub fn get_value<T: Variant + Clone>(&self, name: &str) -> Option<T> {
self.names
.iter()
.rev()
.position(|key| name == key)
.and_then(|i| self.values[self.len() - 1 - i].flatten_clone().try_cast())
}
/// Get a reference the value of an entry in the [`Scope`], starting from the last.
///
/// # Panics
///
/// Panics if the value is _shared_.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
///
/// let ptr = my_scope.get_value_ref::<i64>("x").expect("x should exist");
///
/// assert_eq!(*ptr, 42);
/// ```
#[inline]
#[must_use]
pub fn get_value_ref<T: Variant + Clone>(&self, name: &str) -> Option<&T> {
self.names
.iter()
.rev()
.position(|key| name == key)
.and_then(|i| {
let v = &self.values[self.len() - 1 - i];
#[cfg(not(feature = "no_closure"))]
assert!(!v.is_shared());
v.downcast_ref()
})
}
/// Get a mutable reference the value of an entry in the [`Scope`], starting from the last.
///
/// # Panics
///
/// Panics if the value is _shared_.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
///
/// let ptr = my_scope.get_value_mut::<i64>("x").expect("x should exist");
///
/// *ptr = 0;
///
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 0);
/// ```
#[inline]
#[must_use]
pub fn get_value_mut<T: Variant + Clone>(&mut self, name: &str) -> Option<&mut T> {
let len = self.len();
self.names
.iter_mut()
.rev()
.position(|key| name == key)
.and_then(move |i| {
let v = &mut self.values[len - 1 - i];
#[cfg(not(feature = "no_closure"))]
assert!(!v.is_shared());
v.downcast_mut()
})
}
/// Check if the named entry in the [`Scope`] is constant.
///
/// Search starts backwards from the last, stopping at the first entry matching the specified name.
///
/// Returns [`None`] if no entry matching the specified name is found.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push_constant("x", 42_i64);
/// assert_eq!(my_scope.is_constant("x"), Some(true));
/// assert_eq!(my_scope.is_constant("y"), None);
/// ```
#[inline]
#[must_use]
pub fn is_constant(&self, name: &str) -> Option<bool> {
self.search(name)
.map(|n| match self.values[n].access_mode() {
AccessMode::ReadWrite => false,
AccessMode::ReadOnly => true,
})
}
/// Update the value of the named entry in the [`Scope`] if it already exists and is not constant.
/// Push a new entry with the value into the [`Scope`] if the name doesn't exist or if the
/// existing entry is constant.
///
/// Search starts backwards from the last, and only the first entry matching the specified name is updated.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.set_or_push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
/// assert_eq!(my_scope.len(), 1);
///
/// my_scope.set_or_push("x", 0_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 0);
/// assert_eq!(my_scope.len(), 1);
///
/// my_scope.set_or_push("y", 123_i64);
/// assert_eq!(my_scope.get_value::<i64>("y").expect("y should exist"), 123);
/// assert_eq!(my_scope.len(), 2);
/// ```
#[inline]
pub fn set_or_push(
&mut self,
name: impl AsRef<str> + Into<Identifier>,
value: impl Variant + Clone,
) -> &mut Self {
match self
.search(name.as_ref())
.map(|n| (n, self.values[n].access_mode()))
{
None | Some((.., AccessMode::ReadOnly)) => {
self.push(name, value);
}
Some((index, AccessMode::ReadWrite)) => {
let value_ref = self.values.get_mut(index).unwrap();
*value_ref = Dynamic::from(value);
}
}
self
}
/// Update the value of the named entry in the [`Scope`].
///
/// Search starts backwards from the last, and only the first entry matching the specified name is updated.
/// If no entry matching the specified name is found, a new one is added.
///
/// # Panics
///
/// Panics when trying to update the value of a constant.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
///
/// my_scope.set_value("x", 0_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 0);
/// ```
#[inline]
pub fn set_value(
&mut self,
name: impl AsRef<str> + Into<Identifier>,
value: impl Variant + Clone,
) -> &mut Self {
match self
.search(name.as_ref())
.map(|n| (n, self.values[n].access_mode()))
{
None => {
self.push(name, value);
}
Some((.., AccessMode::ReadOnly)) => panic!("variable {} is constant", name.as_ref()),
Some((index, AccessMode::ReadWrite)) => {
let value_ref = self.values.get_mut(index).unwrap();
*value_ref = Dynamic::from(value);
}
}
self
}
/// Get a reference to an entry in the [`Scope`].
///
/// If the entry by the specified name is not found, [`None`] is returned.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
///
/// let value = my_scope.get("x").expect("x should exist");
///
/// assert_eq!(value.as_int().unwrap(), 42);
///
/// assert!(my_scope.get("z").is_none());
/// ```
#[inline(always)]
#[must_use]
pub fn get(&self, name: &str) -> Option<&Dynamic> {
self.search(name).map(|index| &self.values[index])
}
/// Get a reference to an entry in the [`Scope`] based on the index.
///
/// # Panics
///
/// Panics if the index is out of bounds.
#[inline(always)]
#[allow(dead_code)]
pub(crate) fn get_entry_by_index(&self, index: usize) -> (&str, &Dynamic, &[ImmutableString]) {
(
&self.names[index],
&self.values[index],
if self.aliases.len() > index {
&self.aliases[index]
} else {
&[]
},
)
}
/// Remove the last entry in the [`Scope`] by the specified name and return its value.
///
/// If the entry by the specified name is not found, [`None`] is returned.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 123_i64); // first 'x'
/// my_scope.push("x", 42_i64); // second 'x', shadows first
///
/// assert_eq!(my_scope.len(), 2);
///
/// let value = my_scope.remove::<i64>("x").expect("x should exist");
///
/// assert_eq!(value, 42);
///
/// assert_eq!(my_scope.len(), 1);
///
/// let value = my_scope.get_value::<i64>("x").expect("x should still exist");
///
/// assert_eq!(value, 123);
/// ```
#[inline(always)]
#[must_use]
pub fn remove<T: Variant + Clone>(&mut self, name: &str) -> Option<T> {
self.search(name).and_then(|index| {
self.names.remove(index);
if self.aliases.len() > index {
self.aliases.remove(index);
}
self.values.remove(index).try_cast()
})
}
/// Get a mutable reference to the value of an entry in the [`Scope`].
///
/// If the entry by the specified name is not found, or if it is read-only,
/// [`None`] is returned.
///
/// # Example
///
/// ```
/// use rhai::Scope;
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 42);
///
/// let ptr = my_scope.get_mut("x").expect("x should exist");
/// *ptr = 123_i64.into();
///
/// assert_eq!(my_scope.get_value::<i64>("x").expect("x should exist"), 123);
///
/// my_scope.push_constant("z", 1_i64);
/// assert!(my_scope.get_mut("z").is_none());
/// ```
#[inline]
#[must_use]
pub fn get_mut(&mut self, name: &str) -> Option<&mut Dynamic> {
self.search(name)
.and_then(move |n| match self.values[n].access_mode() {
AccessMode::ReadWrite => Some(self.get_mut_by_index(n)),
AccessMode::ReadOnly => None,
})
}
/// Get a mutable reference to the value of an entry in the [`Scope`] based on the index.
///
/// # Panics
///
/// Panics if the index is out of bounds.
#[inline(always)]
pub(crate) fn get_mut_by_index(&mut self, index: usize) -> &mut Dynamic {
&mut self.values[index]
}
/// Add an alias to an entry in the [`Scope`].
///
/// # Panics
///
/// Panics if the index is out of bounds.
#[cfg(not(feature = "no_module"))]
#[inline]
pub(crate) fn add_alias_by_index(&mut self, index: usize, alias: ImmutableString) -> &mut Self {
if self.aliases.len() <= index {
self.aliases.resize(index + 1, <_>::default());
}
let aliases = self.aliases.get_mut(index).unwrap();
if !aliases.contains(&alias) {
aliases.push(alias);
}
self
}
/// Add an alias to a variable in the [`Scope`] so that it is exported under that name.
/// This is an advanced API.
///
/// Variable aliases are used, for example, in [`Module::eval_ast_as_new`][crate::Module::eval_ast_as_new]
/// to create a new module with exported variables under different names.
///
/// If the alias is empty, then the variable is exported under its original name.
///
/// Multiple aliases can be added to any variable.
///
/// Only the last variable matching the name (and not other shadowed versions) is aliased by this call.
#[cfg(not(feature = "no_module"))]
#[inline]
pub fn set_alias(
&mut self,
name: impl AsRef<str> + Into<Identifier>,
alias: impl Into<ImmutableString>,
) {
if let Some(index) = self.search(name.as_ref()) {
let alias = match alias.into() {
x if x.is_empty() => name.into().into(),
x => x,
};
self.add_alias_by_index(index, alias);
}
}
/// Clone the [`Scope`], keeping only the last instances of each variable name.
/// Shadowed variables are omitted in the copy.
#[inline]
#[must_use]
pub fn clone_visible(&self) -> Self {
let len = self.len();
let mut scope = Self::new();
self.names.iter().rev().enumerate().for_each(|(i, name)| {
if scope.names.contains(name) {
return;
}
let index = len - 1 - i;
let v1 = &self.values[index];
scope.push_entry(name.clone(), v1.access_mode(), v1.clone());
if self.aliases.len() > index {
scope.aliases.resize(scope.len() - 1, <_>::default());
scope.aliases.push(self.aliases[index].clone());
}
});
scope
}
/// Get an iterator to entries in the [`Scope`].
/// Shared values are flatten-cloned.
///
/// # Example
///
/// ```
/// use rhai::{Dynamic, Scope};
///
/// let mut my_scope = Scope::new();
///
/// my_scope.push("x", 42_i64);
/// my_scope.push_constant("foo", "hello");
///
/// let mut iter = my_scope.iter();
///
/// let (name, is_constant, value) = iter.next().expect("value should exist");
/// assert_eq!(name, "x");
/// assert!(!is_constant);
/// assert_eq!(value.cast::<i64>(), 42);
///
/// let (name, is_constant, value) = iter.next().expect("value should exist");
/// assert_eq!(name, "foo");
/// assert!(is_constant);
/// assert_eq!(value.cast::<String>(), "hello");
/// ```
#[inline(always)]
pub fn iter(&self) -> impl Iterator<Item = (&str, bool, Dynamic)> {
self.iter_inner()
.map(|(name, constant, value)| (name.as_str(), constant, value.flatten_clone()))
}
/// Get an iterator to entries in the [`Scope`].
/// Shared values are not expanded.
#[inline(always)]
pub fn iter_raw(&self) -> impl Iterator<Item = (&str, bool, &Dynamic)> {
self.iter_rev_inner()
.map(|(name, constant, value)| (name.as_str(), constant, value))
}
/// Get an iterator to entries in the [`Scope`].
/// Shared values are not expanded.
#[inline]
pub(crate) fn iter_inner(&self) -> impl Iterator<Item = (&ImmutableString, bool, &Dynamic)> {
self.names
.iter()
.zip(self.values.iter())
.map(|(name, value)| (name, value.is_read_only(), value))
}
/// Get a reverse iterator to entries in the [`Scope`].
/// Shared values are not expanded.
#[inline]
pub(crate) fn iter_rev_inner(
&self,
) -> impl Iterator<Item = (&ImmutableString, bool, &Dynamic)> {
self.names
.iter()
.rev()
.zip(self.values.iter().rev())
.map(|(name, value)| (name, value.is_read_only(), value))
}
/// Remove a range of entries within the [`Scope`].
///
/// # Panics
///
/// Panics if the range is out of bounds.
#[inline]
#[allow(dead_code)]
pub(crate) fn remove_range(&mut self, start: usize, len: usize) {
self.values.drain(start..start + len).for_each(|_| {});
self.names.drain(start..start + len).for_each(|_| {});
if self.aliases.len() > start {
if self.aliases.len() <= start + len {
self.aliases.truncate(start);
} else {
self.aliases.drain(start..start + len).for_each(|_| {});
}
}
}
}
impl<K: Into<Identifier>> Extend<(K, Dynamic)> for Scope<'_> {
#[inline]
fn extend<T: IntoIterator<Item = (K, Dynamic)>>(&mut self, iter: T) {
for (name, value) in iter {
self.push_entry(name.into().into(), AccessMode::ReadWrite, value);
}
}
}
impl<K: Into<Identifier>> FromIterator<(K, Dynamic)> for Scope<'_> {
#[inline]
fn from_iter<T: IntoIterator<Item = (K, Dynamic)>>(iter: T) -> Self {
let mut scope = Self::new();
scope.extend(iter);
scope
}
}
impl<K: Into<Identifier>> Extend<(K, bool, Dynamic)> for Scope<'_> {
#[inline]
fn extend<T: IntoIterator<Item = (K, bool, Dynamic)>>(&mut self, iter: T) {
for (name, is_constant, value) in iter {
self.push_entry(
name.into().into(),
if is_constant {
AccessMode::ReadOnly
} else {
AccessMode::ReadWrite
},
value,
);
}
}
}
impl<K: Into<Identifier>> FromIterator<(K, bool, Dynamic)> for Scope<'_> {
#[inline]
fn from_iter<T: IntoIterator<Item = (K, bool, Dynamic)>>(iter: T) -> Self {
let mut scope = Self::new();
scope.extend(iter);
scope
}
}