theory/it.unibo.tuprolog.collections.rete.custom/ReteTree

ReteTree

A RETE-style discrimination network storing Clauses and indexing them for fast retrieval by unification.

Clauses are first split into directives and rules (see Directive/Rule), then, within each of those two families, indexed by their head's functor, then by arity, then recursively by the shape of their first argument (variable, atomic, numeric or compound — see the it.unibo.tuprolog.collections.rete.custom.leaf package), narrowing the set of clauses that get has to actually attempt to unify against a query. This is the storage engine backing both it.unibo.tuprolog.collections.ClauseQueue (ordered) and it.unibo.tuprolog.collections.ClauseMultiSet (unordered), and therefore, transitively, Theory itself.

Types

Companion

object Companion

Properties

clauses

abstract val clauses: Sequence<Clause>

Returns all the Clause this ReteTree is storing

directives

abstract val directives: Sequence<Directive>

Returns all the Directives this ReteTree is storing.

isEmpty

abstract val isEmpty: Boolean

Whether this ReteTree stores no clause at all.

isOrdered

abstract val isOrdered: Boolean

Whether this ReteTree preserves insertion order among clauses of the same family (functor/arity/shape); an unordered tree may return matching clauses in any order, but does not support assertA.

rules

abstract val rules: Sequence<Rule>

Returns all the Rules this ReteTree is storing.

size

abstract val size: Int

Returns the number of Clause stored in this tree

unificator

abstract val unificator: Unificator

The Unificator used to match Clauses stored in this tree against query clauses.

Functions

assertA

abstract fun assertA(clause: Clause)

Inserts the given clause before all other clauses of its own family (same directive-vs-rule status, functor and arity) currently stored in this tree, mutating it in place.

assertZ

abstract fun assertZ(clause: Clause)

Inserts the given clause after all other clauses of its own family currently stored in this tree, mutating it in place.

contains