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 * published by the Free Software Foundation.  Oracle designates this

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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package com.sun.xml.internal.xsom.impl.scd;

import com.sun.xml.internal.xsom.XSAnnotation;

import com.sun.xml.internal.xsom.XSAttGroupDecl;

import com.sun.xml.internal.xsom.XSAttributeDecl;

import com.sun.xml.internal.xsom.XSAttributeUse;

import com.sun.xml.internal.xsom.XSComplexType;

import com.sun.xml.internal.xsom.XSComponent;

import com.sun.xml.internal.xsom.XSContentType;

import com.sun.xml.internal.xsom.XSElementDecl;

import com.sun.xml.internal.xsom.XSFacet;

import com.sun.xml.internal.xsom.XSIdentityConstraint;

import com.sun.xml.internal.xsom.XSModelGroup;

import com.sun.xml.internal.xsom.XSModelGroupDecl;

import com.sun.xml.internal.xsom.XSNotation;

import com.sun.xml.internal.xsom.XSParticle;

import com.sun.xml.internal.xsom.XSSchema;

import com.sun.xml.internal.xsom.XSSimpleType;

import com.sun.xml.internal.xsom.XSWildcard;

import com.sun.xml.internal.xsom.XSXPath;

import com.sun.xml.internal.xsom.visitor.XSFunction;

import java.util.Iterator;

/**

 * Partial default implementation of {@link Axis}.

 *

 * <p>

 * {@link XSParticle}s are skipped in SCD, so this class compensates that.

 * For example, when we are considering a path from {@link XSComplexType},

 * we need to also consider a path from its content type particle (if any.)

 *

 * @author Kohsuke Kawaguchi

 */

abstract class AbstractAxisImpl<T extends XSComponent> implements Axis<T>, XSFunction<Iterator<T>> {

    /**

     * Creates a singleton list.

     */

    protected final Iterator<T> singleton(T t) {

        return Iterators.singleton(t);

    }

    protected final Iterator<T> union(T... items) {

        return new Iterators.Array<T>(items);

    }

    protected final Iterator<T> union(Iterator<? extends T> first, Iterator<? extends T> second) {

        return new Iterators.Union<T>(first,second);

    }

    public Iterator<T> iterator(XSComponent contextNode) {

        return contextNode.apply(this);

    }

    /**

     * Gets the prefix of the axis, like "foo::".

     */

    public String getName() {

        return toString();

    }

    /**

     * Default implementation that simply delegate sto {@link #iterator(XSComponent)}

     */

    public Iterator<T> iterator(Iterator<? extends XSComponent> contextNodes) {

        return new Iterators.Map<T,XSComponent>(contextNodes) {

            protected Iterator<? extends T> apply(XSComponent u) {

                return iterator(u);

            }

        };

    }

    public boolean isModelGroup() {

        return false;

    }

    public Iterator<T> annotation(XSAnnotation ann) {

        return empty();

    }

    public Iterator<T> attGroupDecl(XSAttGroupDecl decl) {

        return empty();

    }

    public Iterator<T> attributeDecl(XSAttributeDecl decl) {

        return empty();

    }

    public Iterator<T> attributeUse(XSAttributeUse use) {

        return empty();

    }

    public Iterator<T> complexType(XSComplexType type) {

        // compensate particle

        XSParticle p = type.getContentType().asParticle();

        if(p!=null)

            return particle(p);

        else

            return empty();

    }

    public Iterator<T> schema(XSSchema schema) {

        return empty();

    }

    public Iterator<T> facet(XSFacet facet) {

        return empty();

    }

    public Iterator<T> notation(XSNotation notation) {

        return empty();

    }

    public Iterator<T> identityConstraint(XSIdentityConstraint decl) {

        return empty();

    }

    public Iterator<T> xpath(XSXPath xpath) {

        return empty();

    }

    public Iterator<T> simpleType(XSSimpleType simpleType) {

        return empty();

    }

    public Iterator<T> particle(XSParticle particle) {

        return empty();

    }

    public Iterator<T> empty(XSContentType empty) {

        return empty();

    }

    public Iterator<T> wildcard(XSWildcard wc) {

        return empty();

    }

    public Iterator<T> modelGroupDecl(XSModelGroupDecl decl) {

        return empty();

    }

    public Iterator<T> modelGroup(XSModelGroup group) {

        // compensate for particles that are ignored in SCD

        return new Iterators.Map<T,XSParticle>(group.iterator()) {

            protected Iterator<? extends T> apply(XSParticle p) {

                return particle(p);

            }

        };

    }

    public Iterator<T> elementDecl(XSElementDecl decl) {

        return empty();

    }

    /**

     * Returns an empty list.

     */

    protected final Iterator<T> empty() {

        return Iterators.empty();

    }

}