private RegExp ParseRepeatExp()
{
RegExp e = this.ParseComplExp();
while (this.Peek("?*+{"))
{
if (this.Match('?'))
{
e = RegExp.MakeOptional(e);
}
else if (this.Match('*'))
{
e = RegExp.MakeRepeat(e);
}
else if (this.Match('+'))
{
e = RegExp.MakeRepeat(e, 1);
}
else if (this.Match('{'))
{
int start = pos;
while (this.Peek("0123456789"))
{
this.Next();
}
if (start == pos)
{
throw new ArgumentException("integer expected at position " + pos);
}
int n = int.Parse(b.Substring(start, pos - start));
int m = -1;
if (this.Match(','))
{
start = pos;
while (this.Peek("0123456789"))
{
this.Next();
}
if (start != pos)
{
m = int.Parse(b.Substring(start, pos - start));
}
}
else
{
m = n;
}
if (!this.Match('}'))
{
throw new ArgumentException("expected '}' at position " + pos);
}
e = m == -1 ? RegExp.MakeRepeat(e, n) : RegExp.MakeRepeat(e, n, m);
}
}
return(e);
}
