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

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package cdc.issues.checks;

import java.io.PrintStream;

import cdc.issues.locations.Location;
import cdc.util.debug.Printables;

/**
 * Implementation of {@link AbstractChecker} that lazily delegate the work to a named checker.
 * 
 * This must be used to define recursive checkers;
 *
 * @param  The checked object type.
 */
public final class LazyChecker extends AbstractChecker {
    /** The name of the referenced checker. */
    private final String name;
    /** The referenced checker. */
    private AbstractChecker delegate = null;

    public LazyChecker(SnapshotManager manager,
                       Class objectClass,
                       String name) {
        super(manager,
              objectClass);
        this.name = name;
    }

    private AbstractChecker resolve() {
        if (delegate == null) {
            this.delegate = getManager().resolve(getObjectClass(), name).orElseThrow();
        }
        return delegate;
    }

    @Override
    public void print(PrintStream out,
                      int level) {
        Printables.indent(out, level);
        out.println("LAZY<" + getObjectClass().getSimpleName() + "> --> " + name);
    }

    @Override
    public boolean isEnabled() {
        return resolve().isEnabled();
    }

    @Override
    public final CheckResult check(CheckContext context,
                                   O object,
                                   Location location) {
        return resolve().check(context, object, location);
    }
}