ReverseFunction.java

package org.vertexium.cypher.functions.string;

import org.vertexium.VertexiumException;
import org.vertexium.cypher.VertexiumCypherQueryContext;
import org.vertexium.cypher.ast.model.CypherAstBase;
import org.vertexium.cypher.executor.ExpressionScope;
import org.vertexium.cypher.functions.CypherFunction;

public class ReverseFunction extends CypherFunction {
    @Override
    public Object invoke(VertexiumCypherQueryContext ctx, CypherAstBase[] arguments, ExpressionScope scope) {
        assertArgumentCount(arguments, 1);

        Object arg0 = ctx.getExpressionExecutor().executeExpression(ctx, arguments[0], scope);

        if (arg0 instanceof String) {
            return new StringBuilder((String) arg0).reverse().toString();
        }

        throw new VertexiumException("not implemented for argument of type " + arg0.getClass().getName());
    }
}