private static string GetFirstSymbol(Bamboo.Parsing.Grammars.Expression expression)
{
if (expression is Bamboo.Parsing.Grammars.Symbol)
{
Bamboo.Parsing.Grammars.Symbol symbol = (Bamboo.Parsing.Grammars.Symbol)expression;
return(symbol.Token);
}
else if (expression is Bamboo.Parsing.Grammars.Concatenation)
{
Bamboo.Parsing.Grammars.Concatenation concatenation = (Bamboo.Parsing.Grammars.Concatenation)expression;
return(GetFirstSymbol(concatenation.Expressions[0]));
}
else
{
throw new System.Exception("INVALID");
}
}
private static void First(string A, Bamboo.Parsing.Grammars.Expression expression, Surf.Set FIRST)
{
List <Bamboo.Parsing.Grammars.Expression> B = ToList(expression);
Surf.Set FIRST_A = (Surf.Set)FIRST.Apply(A);
Union(FIRST_A, ((Surf.Set)FIRST.Apply(((Bamboo.Parsing.Grammars.Symbol)B[0]).Token)).Difference(EPSILON));
int i = 0;
while (((Surf.Set)FIRST.Apply(((Bamboo.Parsing.Grammars.Symbol)B[0]).Token)).Contains("EPSILON") && i < (B.Count - 1))
{
Union(FIRST_A, ((Surf.Set)FIRST.Apply(((Bamboo.Parsing.Grammars.Symbol)B[i + 1]).Token)).Difference(EPSILON));
i++;
}
if (i == (B.Count - 1) && ((Surf.Set)FIRST.Apply(((Bamboo.Parsing.Grammars.Symbol)B[B.Count - 1]).Token)).Contains("EPSILON"))
{
Union(FIRST_A, EPSILON);
}
}
private static List <Bamboo.Parsing.Grammars.Expression> ToList(Bamboo.Parsing.Grammars.Expression expression)
{
List <Bamboo.Parsing.Grammars.Expression> list = new List <Bamboo.Parsing.Grammars.Expression>();
if (expression is Bamboo.Parsing.Grammars.Symbol)
{
Bamboo.Parsing.Grammars.Symbol symbol = (Bamboo.Parsing.Grammars.Symbol)expression;
list.Add(symbol);
}
else if (expression is Bamboo.Parsing.Grammars.Concatenation)
{
Bamboo.Parsing.Grammars.Concatenation concatenation = (Bamboo.Parsing.Grammars.Concatenation)expression;
foreach (Bamboo.Parsing.Grammars.Symbol symbol in concatenation.Expressions)
{
list.Add(symbol);
}
}
else
{
throw new System.Exception("INVALID");
}
return(list);
}
private static bool CanResolve(Bamboo.Parsing.Grammars.Expression expression, List <Bamboo.Parsing.Grammars.Production> remaining)
{
if (expression is Bamboo.Parsing.Grammars.Symbol)
{
Bamboo.Parsing.Grammars.Symbol symbol = (Bamboo.Parsing.Grammars.Symbol)expression;
foreach (Bamboo.Parsing.Grammars.Production production in remaining)
{
if (production.Nonterminal.Equals(symbol.Token))
{
return(false);
}
}
return(true);
}
else if (expression is Bamboo.Parsing.Grammars.Concatenation)
{
Bamboo.Parsing.Grammars.Concatenation concatenation = (Bamboo.Parsing.Grammars.Concatenation)expression;
return(CanResolve(concatenation.Expressions[0], remaining));
}
else
{
throw new System.Exception("INVALID");
}
}
private Surf.Set FOLLOW(Bamboo.Parsing.Grammars.Expression expression)
{
return(FOLLOW(((Bamboo.Parsing.Grammars.Symbol)expression).Token));
}
private Surf.Set FIRST(Bamboo.Parsing.Grammars.Expression expression)
{
return((Surf.Set)first.Apply(((Bamboo.Parsing.Grammars.Symbol)expression).Token));
}
