private NFA parseRegex(String str, ref int loc)
{
NFA builtNFA = new NFA("");
while (loc < str.Length)
{
NFA nextNFA = parseOne(str, ref loc);
builtNFA = builtNFA.conc(nextNFA);
}
return(builtNFA);
}
private NFA parseParenthesis(string str, ref int loc)
{
//str[loc] == '('
loc++;
NFA totalNFA = null;
NFA builtNFA = null;
while (str[loc] != ')')
{
if (loc >= str.Length)
{
throw new RegexException("Regex has a ( without a matching )");
}
if (str[loc] == '|')
{
if (totalNFA == null)
{
totalNFA = builtNFA;
}
else
{
totalNFA = totalNFA.or(builtNFA);
}
builtNFA = null;
loc++;
}
NFA nextNFA = parseOne(str, ref loc);
if (builtNFA == null)
{
builtNFA = nextNFA;
}
else
{
builtNFA = builtNFA.conc(nextNFA);
}
}
if (totalNFA == null)
{
totalNFA = builtNFA;
}
else
{
totalNFA = totalNFA.or(builtNFA);
}
loc++;
//loc is first character after )
return(totalNFA);
}