Struct Predicate 

pub struct Predicate {
    pub op: Option<PredicateOp>,
    pub not_op: Option<PredicateOp>,
    pub const_value: Option<TyValue>,
    pub equivalent: Vec<(Path, Path)>,
    pub arity: Option<usize>,
    pub children: Vec<Option<Self>>,
}

Describes a predicate on an AST node.

Fields

op: Option<PredicateOp>

Match only on nodes performing the given operation.

not_op: Option<PredicateOp>

Match only on nodes which are NOT the given operation.

const_value: Option<TyValue>

Match if the node is a constant with some value.

equivalent: Vec<(Path, Path)>

Match if the descendant nodes specified by the two paths are equal.

arity: Option<usize>

Match if the descendant nodes have a certain number of children.

For piecewise functions, this describes the number of conditional arms.

children: Vec<Option<Self>>

Match only on nodes whos children match the given predicates respectively.

A None value in some position means to skip considering the child in that place, for instance a [None, Some(...)] skips evaluation of a first operand.

Implementations

impl Predicate

pub fn op(op: PredicateOp) -> Self

Creates a predicate matching only on the specified op.

pub fn children(children: Vec<Option<Self>>) -> Self

Creates a predicate matching only the specified children.

A None value in some position means to skip considering the child in that place, for instance a [None, Some(...)] skips evaluation of a first operand.

pub fn matches<N: AstNode>(&self, n: &N) -> bool

Indicates if the predicate matches a given AstNode.

Trait Implementations

impl Clone for Predicate

fn clone(&self) -> Predicate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Predicate

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

Formats the value using the given formatter.

impl Default for Predicate

fn default() -> Predicate

Returns the “default value” for a type.

impl Hash for Predicate

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 PartialEq for Predicate

fn eq(&self, other: &Predicate) -> 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 TryInto<Predicate> for PredSpec

type Error = String

The type returned in the event of a conversion error.

fn try_into(self) -> Result<Predicate, Self::Error>

Performs the conversion.

impl Eq for Predicate

impl StructuralPartialEq for Predicate