private Expression ArithmeticExpression()
{
Expression FirstPointer = Term();
while (Lookahead.Is("+") || Lookahead.Is("-"))
{
string Operator = Lookahead.Lexeme;
Match(Lookahead.Lexeme);
Expression SecondPointer = Term();
FirstPointer = new BinaryOperator(Operator, FirstPointer, SecondPointer);
}
return(FirstPointer);
}
private Expression ComparisonExpression()
{
Expression FirstPointer = ArithmeticExpression();
while (Lookahead.Is(">") || Lookahead.Is("?") || Lookahead.Is("<"))
{
string Operator = Lookahead.Lexeme;
Match(Lookahead.Lexeme);
Expression SecondPointer = ArithmeticExpression();
FirstPointer = new BinaryOperator(Operator, FirstPointer, SecondPointer);
}
return(FirstPointer);
}
private Expression Term()
{
Expression FirstPointer = Factor();
while (Lookahead.Is("*") || Lookahead.Is("/"))
{
string Operator = Lookahead.Lexeme;
Match(Lookahead.Lexeme);
Expression SecondPointer = Factor();
FirstPointer = new BinaryOperator(Operator, FirstPointer, SecondPointer);
}
return(FirstPointer);
}
private Expression Expression()
{
Expression FirstPointer = ComparisonExpression();
while (Lookahead.Is("&") || Lookahead.Is("|") || Lookahead.Is("="))
{
string Operator = Lookahead.Lexeme;
Match(Lookahead.Lexeme);
Expression SecondPointer = ComparisonExpression();
FirstPointer = new BinaryOperator(Operator, FirstPointer, SecondPointer);
}
if (Lookahead.Is(";"))
{
Lookahead = NextToken();
//ParserOutput = FirstPointer.IntoString();
//ParserFinalOutput.Add(ParserOutput);
if (MoreTokens())
{
if (Lookahead.Type == TokenType.Token_IDENTIFIER || Lookahead.Type == TokenType.Token_RESERVEDWORD)// && Lookahead.Type!=TokenType.Token_EOF&& Lookahead.Lexeme!="}" && Lookahead.Lexeme!=")")
{
Expression();
}
}
}
if (Lookahead.Type == TokenType.Token_EOF)
{
ParserOutput = FirstPointer.IntoString();
ParserFinalOutput.Add(ParserOutput);
return(FirstPointer);
}
return(FirstPointer);
}
private Expression Factor()
{
Expression FirstPointer = null;
if (Lookahead.Is("("))
{
Match("(");
FirstPointer = Expression();
Match(")");
return(FirstPointer);
}
if (Lookahead.Is(TokenType.Token_INT_LITERAL))
{
int Value = int.Parse(Lookahead.Lexeme);
Match(ExpressionsID.IntLiteral);
FirstPointer = new IntLiteral(Value);
return(FirstPointer);
}
if (Lookahead.Is(TokenType.Token_IDENTIFIER))
{
FirstPointer = Identifier();
return(FirstPointer);
}
if (Lookahead.Is("if"))
{
Match("if");
Match("(");
Expression Condition = Expression();
Match(")");
Match("{");
Expression Then = Expression();
Match("}");
if (Lookahead.Lexeme != "else")
{
FirstPointer = new If(Condition, Then);
return(FirstPointer);
}
Match("else");
Match("{");
Expression Else = Expression();
Match("}");
FirstPointer = new If(Condition, Then, Else);
return(FirstPointer);
}
if (Lookahead.Is("while"))
{
Match("while");
Match("(");
Expression Condition = Expression();
Match(")");
Match("{");
Expression Body = new Expression();
while (!Lookahead.Is("}"))
{
Body = Expression();
}
Match("}");
FirstPointer = new While(Condition, Body);
return(FirstPointer);
}
if (Lookahead.Type == TokenType.Token_EOF)
{
return(FirstPointer);
}
return(FirstPointer);
}