Package net.hydromatic.morel.util

Interface Unifier.Term

All Known Implementing Classes:

Unifier.Sequence, Unifier.Variable

Enclosing class:

Unifier

public static interface Unifier.Term

Term (variable, symbol or node).

Method Summary

Modifier and Type	Method	Description
<R> R	accept(Unifier.TermVisitor<R> visitor)	Accepts a visitor.
Unifier.Term	apply(Map<Unifier.Variable,Unifier.Term> substitutions)	Applies a substitution to this term.
Unifier.Term	apply1(Unifier.Variable variable, Unifier.Term term)	Applies a single-variable substitution to this term.
void	checkCycle(Map<Unifier.Variable,Unifier.Term> map, Map<Unifier.Variable,Unifier.Variable> active)	Throws CycleException if expanding this term leads to a cycle.
boolean	contains(Unifier.Variable variable)	Returns whether this term references a given variable.
default boolean	couldUnifyWith(Unifier.Term term)	Returns whether this term could possibly unify with another term.

Method Details

apply

Unifier.Term apply(Map<Unifier.Variable,Unifier.Term> substitutions)

Applies a substitution to this term.

apply1

Unifier.Term apply1(Unifier.Variable variable,
 Unifier.Term term)

Applies a single-variable substitution to this term.

contains

boolean contains(Unifier.Variable variable)

Returns whether this term references a given variable.

checkCycle

void checkCycle(Map<Unifier.Variable,Unifier.Term> map,
 Map<Unifier.Variable,Unifier.Variable> active)
         throws Unifier.CycleException

Throws CycleException if expanding this term leads to a cycle.

Throws:

Unifier.CycleException

accept

<R> R accept(Unifier.TermVisitor<R> visitor)

Accepts a visitor.

couldUnifyWith

default boolean couldUnifyWith(Unifier.Term term)

Returns whether this term could possibly unify with another term.

Returns true if this or term is a variable, or if they are sequences with the same operator and number of terms, and if all pairs of those terms could unify.