cdc.issues.checks.CheckContext Maven / Gradle / Ivy

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package cdc.issues.checks;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import cdc.issues.locations.LocatedObject;
import cdc.util.lang.Checks;

/**
 * Calling context passed to checkers.
 * 
 * This may be extended for specific needs.
 */
public class CheckContext {
    /** The empty check context. */
    public static final CheckContext EMPTY = new CheckContext();

    /** The stack of checked located objects. */
    private final List> stack;

    protected CheckContext() {
        this.stack = Collections.emptyList();
    }

    protected CheckContext(List> elements) {
        this.stack = elements;
    }

    /**
     * @return The stack of checked located objects.
     */
    public List> getStack() {
        return stack;
    }

    /**
     * @return The stack size.
     */
    public final int size() {
        return getStack().size();
    }

    /**
     * Returns the located element at an index.
     *
     * @param  The object type.
     * @param objectClass The object class.
     * @param index The index of the searched element.
     * @return The element at index.
     */
    public final  LocatedObject get(Class objectClass,
                                                    int index) {
        return getStack().get(index).cast(objectClass);
    }

    /**
     * Creates a new context by appending an element to stack.
     *
     * @param  The object type.
     * @param element The element to push.
     * @return A new CheckContext with element pushed at end.
     */
    public  CheckContext push(LocatedObject element) {
        Checks.isNotNull(element, "element");

        final List> list = new ArrayList<>(this.stack);
        list.add(element);
        return new CheckContext(list);
    }

    @Override
    public String toString() {
        return getStack().toString();
    }
}