Struct Variable 

pub struct Variable<T>(/* private fields */);

A mutable holder for an initially unknown value.

Implementations

impl<T> Variable<T>

pub fn borrow(&self) -> Ref<'_, Option<T>>

pub fn borrow_mut(&self) -> RefMut<'_, Option<T>>

Trait Implementations

impl<T: Clone> Clone for Variable<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Variable<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for Variable<T>

fn default() -> Variable<T>

Returns the “default value” for a type.

impl<T> FormatHolder for Variable<T>

where T: FormatHolder + Debug + Clone,

fn visit<'a>( &'a self, _f: &mut dyn FnMut(&'a Format) -> Result<()>, ) -> Result<()>

Visit all the formats in self in a depth-first way. Variables are not supported and will cause an error.

fn visit_mut( &mut self, f: &mut dyn FnMut(&mut Format) -> Result<()>, ) -> Result<()>

Mutably visit all the formats in self in a depth-first way.

fn unify(&mut self, _other: Variable<T>) -> Result<()>

Update variables and add missing enum variants so that the terms match. This is a special case of term unification:

fn is_unknown(&self) -> bool

Whether this format is a variable with no known value yet.

fn normalize(&mut self) -> Result<()>

Finalize the formats within self by removing variables and making sure that all eligible tuples are compressed into a TupleArray. Return an error if any variable has an unknown value.

fn reduce(&mut self)

Attempt to remove known variables within self. Silently abort if some variables have unknown values.

impl<T: PartialEq> PartialEq for Variable<T>

fn eq(&self, other: &Variable<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<T: Eq> Eq for Variable<T>

impl<T> StructuralPartialEq for Variable<T>