Struct Scope

pub struct Scope<T> {
    pub item: T,
    pub parent: Option<Rc<RefCell<Scope<T>>>>,
}

General scope object with underlying data structure T.

Scoping is handled by a linked list of Scope objects from the child Scope object (which is the parent of no other scope) to the root (global) Scope object, which has no parent.

Fields

item: T

Underlying scoped data structure.

parent: Option<Rc<RefCell<Scope<T>>>>

Optional pointer to the parent of this scope.

This should be Some(...) for every Scope object except the root node.

This is maintained as an Rc<RefCell<...>> since a single scope can be the parent of multiple other scopes.

Trait Implementations

impl<T: Clone> Clone for Scope<T>

fn clone(&self) -> Scope<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for Scope<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Default> Default for Scope<T>

fn default() -> Scope<T>

Returns the “default value” for a type.

impl<Val: Clone, T> MemoryStore<Val> for Scope<T>

where T: MemoryTable<Val>,

fn set(&mut self, ident: Identifier, value: Val) -> Result<Option<Val>, String>

Sets (or updates) the value in memory for an identifier. Returns the previous value (if exists). Typically, the identifier should already exist in the store, but may not have an existing value.

fn get(&self, ident: &Identifier) -> Option<Val>

Retrieves the value for a particular identifier, if exists.

impl<T: PartialEq> PartialEq for Scope<T>

fn eq(&self, other: &Scope<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<Sym: Clone, Tbl> SymbolStore<Sym> for Scope<Tbl>

where Tbl: SymbolTable<Sym>,

fn define(&mut self, ident: Identifier, symbol: Sym) -> Option<Sym>

Defines (or updates) a symbol in this symbol store. Returns previous symbol if this identifier has been previously declared.

fn resolve(&self, ident: &Identifier) -> Option<Sym>

Resolves a symbol in this symbol store, or None if no symbol exists for the identifier.

impl<T> StructuralPartialEq for Scope<T>