Struct ScopeStack 

pub struct ScopeStack { /* private fields */ }

Mutable stack of active scopes plus their scope-local registries.

The stack always contains an implicit root agent scope. It owns freshness for work that is not nested under an explicit agent; non-agent scopes inherit their nearest agent’s freshness instead of creating a separate budget. Additional scopes are pushed as the public API opens lifecycle spans and removed when those spans close.

Implementations

impl ScopeStack

pub fn new() -> Self

Create a new scope stack containing only the implicit root scope.

Returns

A ScopeStack initialized with a single root scope and no scope-local registries.

pub fn push(&mut self, handle: ScopeHandle)

Push a scope handle onto the top of the stack.

Parameters

• handle: Scope handle to make the new top-most active scope.

pub fn top(&self) -> &ScopeHandle

Return the current top-most scope handle.

Returns

A shared reference to the active scope at the top of the stack.

Notes

This function never returns None because the implicit root scope is always present.

pub fn top_mut(&mut self) -> &mut ScopeHandle

Return the current top-most scope handle mutably.

Returns

A mutable reference to the active scope at the top of the stack.

pub fn root_uuid(&self) -> Uuid

Return the UUID of the implicit root scope.

Returns

The stable UUID of the root scope stored at the bottom of the stack.

pub fn is_propagated_parent(&self, uuid: Uuid) -> bool

Whether uuid is the synthetic parent imported from propagation.

pub fn scopes(&self) -> &[ScopeHandle]

Return the full ordered stack of scope handles.

Returns

A slice of scopes ordered from root to the current top-most scope.

pub fn find(&self, uuid: &Uuid) -> Option<&ScopeHandle>

Find a scope handle by UUID.

Parameters

• uuid: UUID of the scope to search for.

Returns

Some(&ScopeHandle) when the scope is active on this stack and None otherwise.

pub fn remove(&mut self, uuid: &Uuid) -> Result<ScopeHandle>

Remove the current top scope if it matches uuid.

Parameters

• uuid: UUID of the scope expected to be at the top of the stack.

Returns

A Result containing the removed ScopeHandle.

Errors

Returns FlowError::InvalidArgument when the scope exists but is not the current top of the stack or when the caller attempts to remove the implicit root scope. Returns FlowError::NotFound when the UUID is not present on the stack.

Trait Implementations

impl Debug for ScopeStack

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

Formats the value using the given formatter.

impl Default for ScopeStack

fn default() -> Self

Returns the “default value” for a type.