private ILeaf <t1, t2, t3> ParseDelimiters(string Formula)
{
foreach (Dictionary <string, Type> delims in this.DelimiterLeaves)
{
IEnumerable <DelimResult> matches = Formula.IndexesWhere(delims, (d) => Formula.Substring(d.Index).StartsWith(d.Delimiter.Key) && d.LHS.CharacterCount('\'') % 2 == 0 && d.RHS.CharacterCount('\'') % 2 == 0 && d.LHS.CharCountMatches('(', ')') && d.RHS.CharCountMatches('(', ')'), (d1, d2) => d1.Delimiter.Key.Length > d2.Delimiter.Key.Length ? d1 : d2).DefaultIfEmpty(null);
DelimResult match = matches.DefaultIfEmpty(null).LastOrDefault(d =>
d != null &&
d.LHS.CharCountMatches('(', ')') &&
d.RHS.CharCountMatches('(', ')') &&
d.LHS.CharacterCount('\'') % 2 == 0 &&
d.RHS.CharacterCount('\'') % 2 == 0 &&
!this.DelimiterLeaves.SelectMany(d2 => d2.Select(d3 => d3.Key)).Any(d4 => d.LHS.EndsWith(d4)));
if (match != null)
{
if (match.Delimiter.Key.Equals("-") && String.IsNullOrEmpty(match.LHS))
{
return(null);
}
return((BranchingLeaf <t1, t2, t3>)Activator.CreateInstance(match.Delimiter.Value, Formula, Parse(match.LHS), Parse(match.RHS)));
}
}
return(null);
}
internal static IEnumerable <DelimResult> IndexesWhere(this string source, IEnumerable <KeyValuePair <string, Type> > search, Func <DelimResult, bool> predicate, Func <DelimResult, DelimResult, DelimResult> conflictResolution)
{
DelimResult result = null;
IEnumerable <DelimResult> delimResults;
for (int index = 0; index < source.Length; index++)
{
result = null;
delimResults = from s in search where index + s.Key.Length < source.Length select new DelimResult(index, source, s);
foreach (DelimResult d in delimResults)
{
if (predicate(d))
{
result = result == null ? d : conflictResolution(result, d);
}
}
if (result != null)
{
yield return(result);
index += result.Delimiter.Key.Length - 1;
}
}
}
