ConstantExpander.java

package org.aksw.jena_sparql_api.views;


import org.aksw.commons.util.reflect.MultiMethod;
import org.apache.commons.lang.NotImplementedException;
import org.apache.jena.sparql.algebra.Op;
import org.apache.jena.sparql.expr.Expr;
import org.apache.jena.sparql.expr.ExprAggregator;
import org.apache.jena.sparql.expr.ExprFunction;
import org.apache.jena.sparql.expr.ExprFunctionOp;
import org.apache.jena.sparql.expr.ExprList;
import org.apache.jena.sparql.expr.NodeValue;

public class ConstantExpander {

    public static Expr transform(Expr expr) {
        return expr == null ? null : (Expr) MultiMethod.invokeStatic(ConstantExpander.class,
                "_transform", expr);
    }

    public static Expr _transform(ExprFunction expr) {
        ExprList args = transformList(expr.getArgs());

        Expr result = ExprCopy.getInstance().copy(expr, args);
        return result;
    }

    protected static ExprList transformList(Iterable<Expr> exprs) {
        ExprList result = new ExprList();

        for (Expr expr : exprs) {
            result.add(transform(expr));
        }

        return result;
    }

    public static Expr _transform(ExprFunctionOp funcOp, ExprList args, Op opArg) {
        throw new NotImplementedException();
    }

    public static Expr _transform(Expr expr) {
        return expr;
    }

    public static Expr _transform(NodeValue nv)
    {
        return SqlTranslationUtils.expandConstant(nv.asNode());
    }

    public static Expr _transform(ExprAggregator eAgg) {
        throw new NotImplementedException();
    }
}