Discord.Net/src/Discord.Net.Commands/CommandError.cs

namespace Discord.Commands
{
    /// <summary> Defines the type of error a command can throw. </summary>
    public enum CommandError
    {
        //Search
        /// <summary>
        /// Thrown when the command is unknown.
        /// </summary>
        UnknownCommand = 1,

        //Parse
        /// <summary>
        /// Thrown when the command fails to be parsed.
        /// </summary>
        ParseFailed,
        /// <summary>
        /// Thrown when the input text has too few or too many arguments.
        /// </summary>
        BadArgCount,

        //Parse (Type Reader)
        //CastFailed,
        /// <summary>
        /// Thrown when the object cannot be found by the <see cref="TypeReader"/>.
        /// </summary>
        ObjectNotFound,
        /// <summary>
        /// Thrown when more than one object is matched by <see cref="TypeReader"/>.
        /// </summary>
        MultipleMatches,

        //Preconditions
        /// <summary>
        /// Thrown when the command fails to meet a <see cref="PreconditionAttribute"/>'s conditions.
        /// </summary>
        UnmetPrecondition,

        //Execute
        /// <summary>
        /// Thrown when an exception occurs mid-command execution.
        /// </summary>
        Exception,

        //Runtime
        /// <summary>
        /// Thrown when the command is not successfully executed on runtime.
        /// </summary>
        Unsuccessful
    }
}