public static BnfExpression MakePlusRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember)
{
if (delimiter == null)
{
listNonTerminal.Rule = listMember | listNonTerminal + listMember;
}
else
{
listNonTerminal.Rule = listMember | listNonTerminal + delimiter + listMember;
}
listNonTerminal.SetFlag(TermFlags.IsList);
return(listNonTerminal.Rule);
}
//Pipe/Alternative
//New version proposed by the codeplex user bdaugherty
internal static BnfExpression Op_Pipe(BnfTerm term1, BnfTerm term2)
{
BnfExpression expr1 = term1 as BnfExpression;
if (expr1 == null)
{
expr1 = new BnfExpression(term1);
}
BnfExpression expr2 = term2 as BnfExpression;
if (expr2 == null)
{
expr2 = new BnfExpression(term2);
}
expr1.Data.AddRange(expr2.Data);
return(expr1);
}
public BnfExpression(BnfTerm element) : this()
{
Data[0].Add(element);
}
public static BnfExpression MakeStarRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember, TermListOptions options)
{
bool allowTrailingDelimiter = (options & TermListOptions.AllowTrailingDelimiter) != 0;
if (delimiter == null)
{
//it is much simpler case
listNonTerminal.SetFlag(TermFlags.IsList);
listNonTerminal.Rule = _currentGrammar.Empty | listNonTerminal + listMember;
return(listNonTerminal.Rule);
}
//Note that deceptively simple version of the star-rule
// Elem* -> Empty | Elem | Elem* + delim + Elem
// does not work when you have delimiters. This simple version allows lists starting with delimiters -
// which is wrong. The correct formula is to first define "Elem+"-list, and then define "Elem*" list
// as "Elem* -> Empty|Elem+"
NonTerminal plusList = new NonTerminal(listMember.Name + "+");
plusList.Rule = MakePlusRule(plusList, delimiter, listMember);
plusList.SetFlag(TermFlags.NoAstNode); //to allow it to have AstNodeType not assigned
if (allowTrailingDelimiter)
{
listNonTerminal.Rule = _currentGrammar.Empty | plusList | plusList + delimiter;
}
else
{
listNonTerminal.Rule = _currentGrammar.Empty | plusList;
}
listNonTerminal.SetFlag(TermFlags.IsListContainer);
return(listNonTerminal.Rule);
}
public static BnfExpression MakeStarRule(NonTerminal listNonTerminal, BnfTerm delimiter, BnfTerm listMember)
{
return(MakeStarRule(listNonTerminal, delimiter, listMember, TermListOptions.None));
}
}//method
#endregion
#region MakePlusRule, MakeStarRule methods
public static BnfExpression MakePlusRule(NonTerminal listNonTerminal, BnfTerm listMember)
{
return(MakePlusRule(listNonTerminal, null, listMember));
}
public ParseTreeNode(BnfTerm term) : this()
{
Term = term;
}