internal IRule GetRuleWithModifier(string name)
{
/*
* rule?
* rule*
* rule+
* 'rule'
*/
bool sw(string c) => name.StartsWith(c);
bool ew(string c) => name.EndsWith(c);
if (ew("?") || ew("*") || ew("+"))
{
return(ModifiedRule.CreateModifiedRule(GetRule(name.TrimEnd('?', '*', '+')), name.Last()));
}
if (sw("'") && ew("'"))
{
var r = new Lexrule("inline" + inlineId++, name.Trim('\''));
lexer.InsertRule(0, r);
return(r);
}
return(GetRule(name));
}
internal static IRule CreateModifiedRule(IRule inner, char type)
{
ModifiedRule rule = type switch {
'?' => new Optional(),
'*' => new ZeroOrMore(),
'+' => new OneOrMore(),
_ => null
};
if (rule == null)
{
return(inner);
}
rule.inner = inner;
return(rule);
}