Enum Pat 

pub enum Pat<A: AstTypes = DefaultTypes> {
    Ignore,
    Never,
    MetId(A::MacroId),
    Name(A::Symbol),
    Value(Box<At<Expr<A>, A>>),
    Op(PatOp, Vec<Pat<A>>),
}

Binding patterns for each kind of matchable value.

This covers both bindings and type annotations in Bind expressions.

Variants

Ignore

_: Matches anything without binding

Never

!: Matches nothing, ever

MetId(A::MacroId)

$Token: Matches nothing; used for macro substitution

Name(A::Symbol)

Identifier: Matches anything, and binds it to a name

Value(Box<At<Expr<A>, A>>)

Expr: Matches a value by equality comparison

Op(PatOp, Vec<Pat<A>>)

Matches a compound pattern

Implementations

impl<A: AstTypes> Pat<A>

pub fn to_tuple(self) -> Self

Turns this pattern into a tuple if it isn’t already one.

pub fn name(&self) -> Option<A::Symbol>

Returns the single, unambiguous name bound by this pattern, if there is one.

Else, returns None.

Trait Implementations

impl<A: Clone + AstTypes> Clone for Pat<A>

where A::MacroId: Clone, A::Symbol: Clone,

fn clone(&self) -> Pat<A>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<A: Debug + AstTypes> Debug for Pat<A>

where A::MacroId: Debug, A::Symbol: Debug,

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

Formats the value using the given formatter.

impl<A: AstTypes> Display for Pat<A>

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

Formats the value using the given formatter.

impl<A: AstTypes, B: AstTypes> Foldable<A, B> for Pat<A>

type Out = Pat<B>

The return type of the associated Fold function

fn fold_in<F: Fold<A, B> + ?Sized>( self, folder: &mut F, ) -> Result<Self::Out, F::Error>

Calls Self’s appropriate Folder function(s)

fn children<F: Fold<A, B> + ?Sized>( self, folder: &mut F, ) -> Result<Self::Out, F::Error>

Destructures self, calling Foldable::fold_in on all foldable members, and rebuilds a Self out of the results.

impl<A: Hash + AstTypes> Hash for Pat<A>

where A::MacroId: Hash, A::Symbol: Hash,

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<A: AstTypes> Match<A> for Pat<A>

fn recurse(sub: &mut Subst<A>, pat: &Self, expr: &Self) -> bool

Implements recursive Subst-building for Self

fn apply(&mut self, sub: &Subst<A>)

With self as the pattern, recursively applies the Subst

fn apply_rule(&mut self, pat: &Self, template: &Self) -> bool

where Self: Sized + Clone,

Applies a substitution rule from pat to template on self

fn match_with(&self, pat: &Self) -> Option<Subst<A>>

Matches self against the provided pattern

impl<A: PartialEq + AstTypes> PartialEq for Pat<A>

where A::MacroId: PartialEq, A::Symbol: PartialEq,

fn eq(&self, other: &Pat<A>) -> 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<'a, A: AstTypes> Walk<'a, A> for Pat<A>

fn children<V: Visit<'a, A> + ?Sized>( &'a self, v: &mut V, ) -> Result<(), V::Error>

fn visit_in<V: Visit<'a, A> + ?Sized>( &'a self, v: &mut V, ) -> Result<(), V::Error>

impl<A: Eq + AstTypes> Eq for Pat<A>

where A::MacroId: Eq, A::Symbol: Eq,

impl<A: AstTypes> StructuralPartialEq for Pat<A>