public CTLFormula(CTLExpressionType type, CTLFormula left)
{
Type = type;
LeftFormula = left;
}
public CTLFormula(CTLExpressionType type, CTLFormula left, CTLFormula right)
{
Type = type;
LeftFormula = left;
RightFormula = right;
}
public CTLFormula ParseCTLFormula()
{
var token = _lexer.GetToken();
CTLFormula formula;
switch (token.TokenType)
{
case TokenType.True:
return(new CTLFormula(CTLExpressionType.True, "True"));
case TokenType.False:
return(new CTLFormula(CTLExpressionType.False, "False"));
case TokenType.Prop:
{
if (!_propositionsFound.Contains(token.Lexeme))
{
_propositionsFound.Add(token.Lexeme);
}
return(new CTLFormula(CTLExpressionType.Prop, token.Lexeme));
}
case TokenType.LParen:
{
token = _lexer.Peek();
if (token.TokenType == TokenType.Not)
{
formula = new CTLFormula(CTLExpressionType.Not);
_lexer.GetToken(); // remove NOT token as Peek call did not
formula.LeftFormula = ParseCTLFormula();
Expect(TokenType.RParen);
return(formula);
}
if (_firstCTLFormula.Contains(token.TokenType))
{
formula = new CTLFormula();
formula.LeftFormula = ParseCTLFormula();
token = _lexer.GetToken();
switch (token.TokenType)
{
case TokenType.And:
formula.Type = CTLExpressionType.And;
break;
case TokenType.Or:
formula.Type = CTLExpressionType.Or;
break;
case TokenType.Implies:
formula.Type = CTLExpressionType.Implies;
break;
case TokenType.IFF:
formula.Type = CTLExpressionType.IFF;
break;
default:
Error(token);
break;
}
formula.RightFormula = ParseCTLFormula();
Expect(TokenType.RParen);
return(formula);
}
Error(token);
break;
}
case TokenType.AX:
{
formula = new CTLFormula(CTLExpressionType.AX);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.AF:
{
formula = new CTLFormula(CTLExpressionType.AF);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.AG:
{
formula = new CTLFormula(CTLExpressionType.AG);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.EX:
{
formula = new CTLFormula(CTLExpressionType.EX);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.EF:
{
formula = new CTLFormula(CTLExpressionType.EF);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.EG:
{
formula = new CTLFormula(CTLExpressionType.EG);
formula.LeftFormula = ParseCTLFormula();
return(formula);
}
case TokenType.A:
{
Expect(TokenType.LBrack);
formula = new CTLFormula(CTLExpressionType.AU);
formula.LeftFormula = ParseCTLFormula();
Expect(TokenType.U);
formula.RightFormula = ParseCTLFormula();
Expect(TokenType.RBrack);
return(formula);
}
case TokenType.E:
{
Expect(TokenType.LBrack);
formula = new CTLFormula(CTLExpressionType.EU);
formula.LeftFormula = ParseCTLFormula();
Expect(TokenType.U);
formula.RightFormula = ParseCTLFormula();
Expect(TokenType.RBrack);
return(formula);
}
}
Error(token);
return(null);
}