// ****************************************************************
// Copyright 2007, Charlie Poole
// This is free software licensed under the NUnit license. You may
// obtain a copy of the license at http://nunit.org
// ****************************************************************

namespace NUnit.Framework.Constraints
{
    /// <summary>
    /// OrConstraint succeeds if either member succeeds
    /// </summary>
    public class OrConstraint : BinaryConstraint
    {
        /// <summary>
        /// Create an OrConstraint from two other constraints
        /// </summary>
        /// <param name="left">The first constraint</param>
        /// <param name="right">The second constraint</param>
        public OrConstraint(Constraint left, Constraint right) : base(left, right) { }

        /// <summary>
        /// Apply the member constraints to an actual value, succeeding 
        /// succeeding as soon as one of them succeeds.
        /// </summary>
        /// <param name="actual">The actual value</param>
        /// <returns>True if either constraint succeeded</returns>
        public override bool Matches(object actual)
        {
            this.actual = actual;
            return left.Matches(actual) || right.Matches(actual);
        }

        /// <summary>
        /// Write a description for this contraint to a MessageWriter
        /// </summary>
        /// <param name="writer">The MessageWriter to receive the description</param>
        public override void WriteDescriptionTo(MessageWriter writer)
        {
            left.WriteDescriptionTo(writer);
            writer.WriteConnector("or");
            right.WriteDescriptionTo(writer);
        }
    }
}
