Struct PartialScopeStack

#[repr(C)]
pub struct PartialScopeStack { /* private fields */ }

A pattern that might match against a scope stack. Consists of a (possibly empty) list of exported scopes, along with an optional scope stack variable.

Implementations

impl PartialScopeStack

pub fn can_match_empty(&self) -> bool

Returns whether this partial scope stack can match the empty scope stack.

pub fn can_only_match_empty(&self) -> bool

Returns whether this partial scope stack can only match the empty scope stack.

pub fn contains_scopes(&self) -> bool

Returns whether this partial scope stack contains any scopes.

pub fn has_variable(&self) -> bool

Returns whether this partial scope stack has a scope stack variable.

pub fn len(&self) -> usize

pub fn empty() -> PartialScopeStack

Returns an empty partial scope stack.

pub fn from_variable(variable: ScopeStackVariable) -> PartialScopeStack

Returns a partial scope stack containing only a scope stack variable.

pub fn have_reversal(&self, partials: &PartialPaths) -> bool

Returns whether this partial scope stack is iterable in both directions without needing mutable access to the arena.

pub fn with_offset(self, scope_variable_offset: u32) -> PartialScopeStack

Applies an offset to this partial scope stack.

When concatenating partial paths, we have to ensure that the left- and right-hand sides have non-overlapping sets of variables. To do this, we find the maximum value of any variable on the left-hand side, and add this “offset” to the values of all of the variables on the right-hand side.

pub fn matches( self, partials: &mut PartialPaths, other: PartialScopeStack, ) -> bool

Returns whether two partial scope stacks match exactly the same set of scope stacks.

pub fn apply_partial_bindings( self, partials: &mut PartialPaths, scope_bindings: &PartialScopeStackBindings, ) -> Result<PartialScopeStack, PathResolutionError>

Applies a set of partial scope stack bindings to this partial scope stack, producing a new partial scope stack.

pub fn unify( self, partials: &mut PartialPaths, rhs: PartialScopeStack, bindings: &mut PartialScopeStackBindings, ) -> Result<PartialScopeStack, PathResolutionError>

Given two partial scope stacks, returns the largest possible partial scope stack such that any scope stack that satisfies the result also satisfies both inputs. This takes into account any existing variable assignments, and updates those variable assignments with whatever constraints are necessary to produce a correct result.

Note that this operation is commutative. (Concatenating partial paths, defined in PartialPath::concatenate, is not.)

pub fn push_front(&mut self, partials: &mut PartialPaths, node: Handle<Node>)

Pushes a new Node onto the front of this partial scope stack. The node must be an exported scope node.

pub fn push_back(&mut self, partials: &mut PartialPaths, node: Handle<Node>)

Pushes a new Node onto the back of this partial scope stack. The node must be an exported scope node.

pub fn pop_front(&mut self, partials: &mut PartialPaths) -> Option<Handle<Node>>

Removes and returns the Node at the front of this partial scope stack. If the stack does not contain any exported scope nodes, returns None.

pub fn pop_back(&mut self, partials: &mut PartialPaths) -> Option<Handle<Node>>

Removes and returns the Node at the back of this partial scope stack. If the stack does not contain any exported scope nodes, returns None.

pub fn variable(&self) -> Option<ScopeStackVariable>

Returns the scope stack variable at the end of this partial scope stack. If the stack does not contain a scope stack variable, returns None.

pub fn equals( self, partials: &mut PartialPaths, other: PartialScopeStack, ) -> bool

pub fn cmp( self, partials: &mut PartialPaths, other: PartialScopeStack, ) -> Ordering

pub fn iter_scopes<'a>( &self, partials: &'a mut PartialPaths, ) -> impl Iterator<Item = Handle<Node>> + 'a

Returns an iterator over the scopes in this partial scope stack.

pub fn iter_unordered<'a>( &self, partials: &'a PartialPaths, ) -> impl Iterator<Item = Handle<Node>> + 'a

Returns an iterator over the contents of this partial scope stack, with no guarantee about the ordering of the elements.

pub fn display<'a>( self, graph: &'a StackGraph, partials: &'a mut PartialPaths, ) -> impl Display + 'a

pub fn largest_scope_stack_variable(&self) -> u32

Returns the largest value of any scope stack variable in this partial scope stack.

Trait Implementations

impl Clone for PartialScopeStack

fn clone(&self) -> PartialScopeStack

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl From<PartialScopeStack> for sg_partial_scope_stack

fn from(stack: PartialScopeStack) -> sg_partial_scope_stack

Converts to this type from the input type.

impl Niche for PartialScopeStack

where Deque<Handle<Node>>: Niche,

type Output = MaybeUninit<PartialScopeStack>

The type that is used to store values of Self inside of a ControlledOption. This might be Self itself, if your niche is a valid instance of the type, but which violates some runtime constraint. But if you cannot easily create your niche as an instance of Self, you can use some other type, you can use some other type instead.

fn none() -> Self::Output

Returns the niche value for this type that should be used to represent None for a ControlledOption.

fn is_none(value: &Self::Output) -> bool

Returns whether value is the niche value for this type.

fn into_some(value: Self) -> Self::Output

Transforms a non-niche value of this type into its Output type. When Output is Self, this will be the identity function.

fn from_some(value: Self::Output) -> Self

Transforms a non-niche value of this type from its Output type. When Output is Self, this will be the identity function.

impl Copy for PartialScopeStack