IValuedNode.cs

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using System;
using VDS.RDF.Query;
using VDS.RDF.Query.Expressions;

namespace VDS.RDF.Nodes
{
    /// <summary>
    /// Interface for Valued Nodes.
    /// </summary>
    /// <remarks>
    /// <para>
    /// This interface extends the basic <see cref="INode">INode</see> interface with methods related to turning the lexical value into a strongly typed .Net value.  It is intended primarily for use within SPARQL expression evaluation where we need to do a lot of value conversions and currently waste a lot of effort (and thus performance) doing that.
    /// </para>
    /// </remarks>
    public interface IValuedNode 
        : INode
    {
        /// <summary>
        /// Gets the String value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <remarks>
        /// This is distinct from <strong>ToString()</strong> because that method will typically include additional information like language specifier/datatype as appropriate whereas this method is used to produce a string as would be produced by applying the <strong>STR()</strong> function from SPARQL.
        /// </remarks>
        string AsString();

        /// <summary>
        /// Gets the Long value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Long.</exception>
        long AsInteger();

        /// <summary>
        /// Gets the Decimal value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Decimal.</exception>
        decimal AsDecimal();

        /// <summary>
        /// Gets the Float value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Float.</exception>
        float AsFloat();

        /// <summary>
        /// Gets the Double value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Double.</exception>
        double AsDouble();

        /// <summary>
        /// Gets the Boolean value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Boolean.</exception>
        bool AsBoolean();

        /// <summary>
        /// Gets the Date Time value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Date Time.</exception>
        DateTime AsDateTime();

        /// <summary>
        /// Gets the Date Time Offset value of the Node.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="RdfQueryException">Thrown if the Node cannot be converted to a Date Time Offset.</exception>
        DateTimeOffset AsDateTimeOffset();

        /// <summary>
        /// Gets the Time Span value of the Node.
        /// </summary>
        /// <returns></returns>
        TimeSpan AsTimeSpan();

        /// <summary>
        /// Gets the URI of the datatype this valued node represents as a String.
        /// </summary>
        /// <remarks>
        /// Either String.Empty if no type or the string form of the type URI.
        /// </remarks>
        string EffectiveType
        {
            get;
        }

        /// <summary>
        /// Gets the Numeric Type of the Node.
        /// </summary>
        SparqlNumericType NumericType
        {
            get;
        }
    }
}