/// <summary>
/// Returns true if the parser successfully parses a BNF file. Else, check errorText.
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public bool Parse(String input)
{
try
{
fileText = input.Trim(); ;
rules = new List<NonterminalHeadD>();
if (String.IsNullOrEmpty(fileText))
throw new Exception("Input is null or empty.");
// lexical analysis
LexicalAnalyser lexA = new LexicalAnalyser(fileText);
if (!lexA.Analyse())
{
errorText = lexA.ErrorMsg;
return false;
}
// syntactic analysis
SyntaxAnalyser synA = new SyntaxAnalyser(lexA);
if (!synA.Analyse())
{
errorText = synA.ErrorMsg;
return false;
}
// semantic analysis
SemanticAnalyser semA = new SemanticAnalyser(synA);
if (!semA.Analyse())
{
errorText = semA.ErrorMsg;
return false;
}
// save the rules form semantic analyser :-)
rules = semA.Rules;
if (rules == null || rules.Count == 0)
throw new Exception("The semantic analyser did not find any rules in the input text.");
return true;
}
catch (Exception e)
{
errorText = e.Message;
return false;
}
}
public SyntaxAnalyser(LexicalAnalyser lexAIn)
{
Init(lexAIn);
}
private void Init(LexicalAnalyser lexAIn)
{
lexA = lexAIn;
current = 0;
productionRulesHead = new List<Lexeme>();
productionRulesTail = new ArrayList();
inRule = false;
}