Struct Symbol 

pub struct Symbol { /* private fields */ }

A symbol in a given scope.

Implementations

impl Symbol

pub fn name(&self) -> &Name

pub fn is_used(&self) -> bool

Is the symbol used in its containing scope?

pub const fn is_bound(&self) -> bool

Is the symbol given a value in its containing scope?

pub fn is_declared(&self) -> bool

Is the symbol declared in its containing scope?

pub fn is_global(&self) -> bool

Is the symbol global its containing scope?

pub fn is_nonlocal(&self) -> bool

Is the symbol nonlocal its containing scope?

pub fn is_local(&self) -> bool

Is the symbol defined in this scope, vs referring to some enclosing scope?

There are three common cases where a name refers to an enclosing scope:

1. explicit global variables
2. explicit nonlocal variables
3. “free” variables, which are used in a scope where they’re neither bound nor declared

Note that even if is_local is false, that doesn’t necessarily mean there’s an enclosing scope that resolves the reference. The symbol could be a built-in like print, or a name error at runtime, or a global variable added dynamically with e.g. globals().

XXX: There’s a fourth case that we don’t (can’t) handle here. A variable that’s bound or declared (anywhere) in a class body, but used before it’s bound (at runtime), resolves (unbelievably) to the global scope. For example:

x = 42
def f():
    x = 43
    class Foo:
        print(x)  # 42 (never 43)
        if secrets.randbelow(2):
            x = 44
        print(x)  # 42 or 44

In cases like this, the resolution isn’t known until runtime, and in fact it varies from one use to the next. The semantic index alone can’t resolve this, and instead it’s a special case in type inference (see infer_place_load).

pub const fn is_reassigned(&self) -> bool

Trait Implementations

impl Clone for Symbol

fn clone(&self) -> Symbol

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Symbol

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

Formats the value using the given formatter.

impl Display for Symbol

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

Formats the value using the given formatter.

impl Eq for Symbol

impl<'a> From<&'a Symbol> for PlaceExprRef<'a>

fn from(value: &'a Symbol) -> Self

Converts to this type from the input type.

impl GetSize for Symbol

fn get_heap_size(&self) -> usize

Determines how many bytes this object occupies inside the heap.

fn get_heap_size_with_tracker<TRACKER: GetSizeTracker>( &self, tracker: TRACKER, ) -> (usize, TRACKER)

Determines how many bytes this object occupies inside the heap while using a tracker.

fn get_stack_size() -> usize

Determines how may bytes this object occupies inside the stack.

fn get_size(&self) -> usize

Determines the total size of the object.

fn get_size_with_tracker<T>(&self, tracker: T) -> (usize, T)

where T: GetSizeTracker,

Determines the total size of the object while using a tracker.

impl PartialEq for Symbol

fn eq(&self, other: &Symbol) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Symbol