/// <summary>
/// Builds the set of rule definitions that represents a single virtual symbol
/// </summary>
/// <param name="node">The AST node of a syntactic rule</param>
/// <returns>The set of possible rule definitions</returns>
private RuleBodySet BuildAtomicVirtual(ASTNode node)
{
RuleBodySet set = new RuleBodySet();
string name = node.Children[0].Value;
name = ReplaceEscapees(name.Substring(1, name.Length - 2));
Virtual vir = grammar.GetVirtual(name) ?? grammar.AddVirtual(name);
set.Add(new RuleBody(vir));
return(set);
}
/// <summary>
/// Adds a virtual symbol with the given name to this grammar
/// </summary>
/// <param name="name">The virtual's name</param>
/// <returns>The new virtual</returns>
public Virtual AddVirtual(string name)
{
if (virtuals.ContainsKey(name))
{
return(virtuals[name]);
}
Virtual symbol = new Virtual(nextSID, name);
nextSID++;
virtuals.Add(name, symbol);
return(symbol);
}
/// <summary>
/// Inherits the virtuals from the parent grammar
/// </summary>
/// <param name="parent">The parent's grammar</param>
/// <param name="doClone">Clone the symbols</param>
private void InheritVirtuals(Grammar parent, bool doClone)
{
foreach (Virtual vir in parent.Virtuals)
{
if (doClone)
{
Virtual clone = new Virtual(vir.ID, vir.Name);
virtuals.Add(clone.Name, clone);
}
else
{
if (!virtuals.ContainsKey(vir.Name))
{
AddVirtual(vir.Name);
}
}
}
}