Enum BodyLiteral 

pub enum BodyLiteral {
    Positive(Atom),
    Negated(Atom),
    Epistemic(EpistemicLiteral),
    Comparison(Comparison),
    IsExpr(IsExpr),
    Univ(Univ),
}

A literal in the body of a rule

Variants

Positive(Atom)

Positive atom.

Negated(Atom)

Negated atom (not p(...)).

Epistemic(EpistemicLiteral)

Epistemic atom (know p(...), possible p(...), or negated form).

Comparison(Comparison)

Arithmetic comparison (e.g. X < Y).

IsExpr(IsExpr)

Is-expression binding (e.g. Z is X + Y).

Univ(Univ)

Finite univ relation (Term =.. Parts).

Implementations

impl BodyLiteral

pub fn is_positive(&self) -> bool

Returns true if this is a positive literal.

pub fn is_negated(&self) -> bool

Returns true if this is a negated literal.

pub fn atom(&self) -> Option<&Atom>

Returns the atom if this is a positive or negated literal.

pub fn variables(&self) -> Vec<&str>

Collect all named variables referenced by this literal.

Trait Implementations

impl Clone for BodyLiteral

fn clone(&self) -> BodyLiteral

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BodyLiteral

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

Formats the value using the given formatter.

impl PartialEq for BodyLiteral

fn eq(&self, other: &BodyLiteral) -> 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 StructuralPartialEq for BodyLiteral