/// <summary>
/// Try to match a function on the enumerator ensuring that the enumerator is restored on failure.
/// </summary>
/// <param name="enumerator">The enumerator to attempt to match on.</param>
/// <param name="make">The callback function to match on the enumerator.</param>
/// <param name="found">The out value that was found.</param>
/// <returns>true if the matching function successfully made a match, false if not.</returns>
static bool TryMake <T>(TokenEnumerator enumerator, TryMakeDelegate <T> make, out T found)
{
using (var checkpoint = enumerator.Checkpoint())
{
if (make(enumerator, out found))
{
return(true);
}
checkpoint.Rollback();
}
return(false);
}