// ParametersTail -> CommaToken IdentifierToken ParametersTail |
// CommaToken NumberToken ParametersTail |
// e
private bool ProcessParametersTail()
{
if (LexicalAnaylzer.Token == Token.CommaToken && LexicalAnaylzer.IsFirstWordCharacter(LexicalAnaylzer.LookNextCharacter()))
{ // TODO: This isn't good - will work for this grammar but shouldn't be checking just next character like so
LexicalAnaylzer.GetNextToken();
if (!CheckDeclaredVariable())
{
return(false);
}
ParameterStack.Push(LexicalAnaylzer.Lexeme);
if (!MatchToken(Token.IdentifierToken))
{
return(false);
}
if (!ProcessParametersTail())
{
return(false);
}
}
else if (LexicalAnaylzer.Token == Token.CommaToken && LexicalAnaylzer.IsDigitCharacter(LexicalAnaylzer.LookNextCharacter()))
{ // TODO: This isn't good - will work for this grammar but shouldn't be checking just next character like so
LexicalAnaylzer.GetNextToken();
ParameterStack.Push(LexicalAnaylzer.Lexeme);
if (!MatchToken(Token.NumberToken))
{
return(false);
}
if (!ProcessParametersTail())
{
return(false);
}
}
return(true);
}
// Parameters -> IdentifierToken ParametersTail |
// NumberToken ParametersTail |
// e
private bool ProcessParameters()
{
if (LexicalAnaylzer.Token == Token.IdentifierToken)
{
if (!CheckDeclaredVariable())
{
return(false);
}
ParameterStack.Push(LexicalAnaylzer.Lexeme);
LexicalAnaylzer.GetNextToken();
if (!ProcessParametersTail())
{
return(false);
}
}
else if (LexicalAnaylzer.Token == Token.NumberToken)
{
ParameterStack.Push(LexicalAnaylzer.Lexeme);
LexicalAnaylzer.GetNextToken();
if (!ProcessParametersTail())
{
return(false);
}
}
return(true);
}
// Program -> Type IdentifierToken Rest Program |
// ConstToken IdentifierToken AssignmentOperatorToken NumberToken SemiColonToken Program |
// e
private bool ProcessProgram()
{
if (IsVariableType(LexicalAnaylzer.Token))
{
CurrentFunction.ReturnType = LexicalAnaylzer.Token;
if (!ProcessType())
{
return(false);
}
CurrentVariable.Lexeme = LexicalAnaylzer.Lexeme;
CurrentFunction.Lexeme = LexicalAnaylzer.Lexeme;
if (!MatchToken(Token.IdentifierToken))
{
return(false);
}
if (!ProcessRest())
{
return(false);
}
if (!ProcessProgram())
{
return(false);
}
}
else if (LexicalAnaylzer.Token == Token.ConstToken)
{
LexicalAnaylzer.GetNextToken();
CurrentConstant.Lexeme = LexicalAnaylzer.Lexeme;
if (!MatchToken(Token.IdentifierToken))
{
return(false);
}
if (!MatchToken(Token.AssignmentOperatorToken))
{
return(false);
}
if (!InsertConstantNode())
{
return(false);
}
if (!MatchToken(Token.NumberToken))
{
return(false);
}
if (!MatchToken(Token.SemiColonToken))
{
return(false);
}
if (!ProcessProgram())
{
return(false);
}
}
return(true);
}
// Matches expected symbol to current symbol from lexical analyzer
private bool MatchToken(Token expectedSymbol)
{
if (LexicalAnaylzer.Token == expectedSymbol)
{
LexicalAnaylzer.GetNextToken();
return(true);
}
DisplayExpectedTokensError(expectedSymbol.ToString());
return(false);
}
