grakn.core.graql.reasoner.cache.VariableDefinition.java Source code

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Here is the source code for grakn.core.graql.reasoner.cache.VariableDefinition.java

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/*
 * GRAKN.AI - THE KNOWLEDGE GRAPH
 * Copyright (C) 2018 Grakn Labs Ltd
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package grakn.core.graql.reasoner.cache;

import com.google.common.collect.Sets;
import grakn.core.concept.type.Role;
import grakn.core.concept.type.Type;
import grakn.core.graql.reasoner.atom.predicate.ValuePredicate;
import graql.lang.statement.Variable;

import javax.annotation.Nullable;
import java.util.Objects;
import java.util.Set;

/**
 * Defines a variable specification in the form:
 * - type,
 * - role (if corresponds to role variable
 * - roles it plays (if corresponds to roleplayer variable)
 * - valuePredicates it has
 */
public class VariableDefinition {

    final private Variable var;
    final private Type type;
    final private Role role;
    final private Set<Role> playedRoles;
    final private Set<ValuePredicate> vps;

    public VariableDefinition(Variable var, @Nullable Type type, @Nullable Role role, Set<Role> playedRoles,
            Set<ValuePredicate> vps) {
        this.var = var;
        this.type = type;
        this.role = role;
        this.playedRoles = playedRoles;
        this.vps = vps;
    }

    @Override
    public String toString() {
        return "{" + var + ":{" + "type: " + type + ", " + "role: " + role + ", " + "playedRoles: " + playedRoles
                + ", " + "vps: " + vps + "}}";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (o == null || getClass() != o.getClass())
            return false;
        VariableDefinition that = (VariableDefinition) o;
        return Objects.equals(var, that.var) && Objects.equals(type, that.type) && Objects.equals(role, that.role)
                && Objects.equals(playedRoles, that.playedRoles) && Objects.equals(vps, that.vps);
    }

    @Override
    public int hashCode() {
        return Objects.hash(var, type, role, playedRoles, vps);
    }

    public Variable var() {
        return var;
    }

    public Type type() {
        return type;
    }

    public Role role() {
        return role;
    }

    public Set<Role> playedRoles() {
        return playedRoles;
    }

    public Set<ValuePredicate> valuePredicates() {
        return vps;
    }

    public VariableDefinition merge(VariableDefinition def) {
        if (!var().equals(def.var())) {
            throw new IllegalStateException("Illegal variable definition merge between:\n" + this + "and\n" + def);
        }
        return new VariableDefinition(var, def.type() != null ? def.type() : this.type(),
                def.role() != null ? def.role() : this.role(), Sets.union(def.playedRoles(), this.playedRoles()),
                Sets.union(def.valuePredicates(), this.valuePredicates()));
    }

    public boolean isTrivial() {
        return type == null && role == null && playedRoles.isEmpty() && vps.isEmpty();
    }
}