Enum polytype::UnificationError

pub enum UnificationError<N: Name = &'static str> {
    Occurs(Variable),
    Failure(Type<N>, Type<N>),
}

Errors during unification.

Variants

Occurs(Variable)

Occurs happens when occurs checks fail (i.e. a type variable is unified recursively). The id of the bad type variable is supplied.

Failure(Type<N>, Type<N>)

Failure happens when symbols or type variants don't unify because of structural differences.

Trait Implementations

impl<N: PartialEq + Name> PartialEq<UnificationError<N>> for UnificationError<N>

fn eq(&self, other: &UnificationError<N>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &UnificationError<N>) -> bool

This method tests for !=.

impl<N: Clone + Name> Clone for UnificationError<N>

fn clone(&self) -> UnificationError<N>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<N: Name> Display for UnificationError<N>

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

Formats the value using the given formatter.

impl<N: Debug + Name> Debug for UnificationError<N>

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

Formats the value using the given formatter.

impl<N: Name + Debug> Error for UnificationError<N>

fn description(&self) -> &'static str

This method is soft-deprecated.

fn cause(&self) -> Option<&dyn Error>

Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

The lower-level cause of this error, if any.

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.