/// <summary>
/// Build all rules for nonterminal
/// </summary>
/// <param name="grammarRuleContext"></param>
private void BuildGrammarRule(GrammarRuleContext grammarRuleContext)
{
string name = grammarRuleContext.grammarName().GetText();
//save start rule
if (firstRuleName.Equals(""))
{
firstRuleName = name;
}
if (NonTerminals.ContainsKey(name))
{
throw new GrammarBuilderException($"Nonterminal {name} is defined twice");
}
var nonTerminal = NonTerminals[name] = new NonTerminal(name);
ProductionsContext productions = grammarRuleContext.productions();
do
{
nonTerminal.Productions.Add(BuildProduction(productions.production()));
productions = productions.productions();
} while (productions != null);
}
/// <summary>
/// Initialize NonTerminals and Terminals with rules.
///
/// </summary>
public void Build()
{
GrammarFileGrammarLexer speakLexer = new GrammarFileGrammarLexer(inputStream);
CommonTokenStream commonTokenStream = new CommonTokenStream(speakLexer);
GrammarFileGrammarParser grammarParser = new GrammarFileGrammarParser(commonTokenStream);
foreach (var line in grammarParser.file().line())
{
if (line.lexerRule() != null)
{
BuildLexerRule(line.lexerRule());
}
else
{
BuildGrammarRule(line.grammarRule());
}
}
InputStartNonTerminal = StartNonTerminal = NonTerminals[firstRuleName];
if (NonTerminals.ContainsKey("startRule"))
{
throw new Exception("The name \"startRule\" is reserved, change the name for this nonterminal");
}
NonTerminals.Add("startRule", new NonTerminal("startRule"));
NonTerminals["startRule"].AddRule(new Production(productionRuleID++, new NonTerminalProduction(firstRuleName)));
firstRuleName = "startRule";
StartNonTerminal = NonTerminals[firstRuleName];
///Checking, that we have all terminals and nonterminals, which was mentioned in rules
foreach (var nonTerminals in NonTerminals.Values)
{
foreach (var rule in nonTerminals.Productions)
{
foreach (var element in rule.ProductionElements)
{
if (element is TerminalProduction)
{
var e = element as TerminalProduction;
if (e.needSetTerminal)
{
if (!Terminals.ContainsKey(e.Name))
{
throw new Exception($"Nonterminal {e} is not defined");
}
e.Terminal = Terminals[e.Name];
}
}
else if (element is NonTerminalProduction)
{
var e = element as NonTerminalProduction;
if (!NonTerminals.ContainsKey(e.Name))
{
throw new Exception($"Nonterminal {e} is not defined");
}
e.NonTerminal = NonTerminals[e.Name];
}
}
}
}
//Calculate FIRST and FOLLOW for each nonterminal
//First:
CalculateFirst();
//Follow
CalculateFollow();
}