/// <summary>
/// Reads a specific rule from the input. The rule is given in the format:
/// 80: 116 116 | 119 134
/// Where the '|' character seperates alternative sub-rules.
/// </summary>
/// <param name="input">The input.</param>
/// <returns>The list of sub-rules.</returns>
private List <Rule> ReadRule(string input)
{
var subRules = input
.Split(new[] { " | " }, StringSplitOptions.None)
.Select(x => x.Split().ToList())
.ToList();
var rules = new List <Rule>();
foreach (var subRule in subRules)
{
if (subRule.Count == 1 && subRule[0].Contains("\""))
{
var rule = new RuleToken()
{
Value = subRule[0][1]
};
rules.Add(rule);
}
else
{
var rule = new RuleSequence()
{
Nodes = subRule
.Select(x => int.Parse(x))
.ToList()
};
rules.Add(rule);
}
}
return(rules);
}
/// <summary>
/// Consumes a single character, and returns the new position (as
/// an enumerator to match other consume methods).
/// </summary>
/// <param name="message">The message.</param>
/// <param name="rule">The rule.</param>
/// <param name="position">The current position.</param>
/// <returns>The next position.</returns>
private IEnumerable <int> ConsumeRule(string message, RuleToken rule, int position)
{
if (position >= message.Length)
{
yield break;
}
var expected = rule.Value;
if (message[position] == expected)
{
yield return(position + 1);
}
}
