private Expression ParseTerm()
{
Token firstTermToken = CurrentToken;
Expression left = ParseFactor();
while (Accept(TokenType.OpMultiply, TokenType.OpDivide, TokenType.OpModulus, TokenType.OpAnd))
{
BinaryExpr expr = new BinaryExpr(firstTermToken);
expr.SetOperatorFromToken(AcceptedToken);
expr.Left = left;
expr.Right = ParseFactor();
left = expr;
}
return(left);
}
private Expression ParseExpression()
{
Token firstTermToken = CurrentToken;
Expression left = ParseSimpleExpression();
if (Accept(TokenType.OpLess, TokenType.OpLessOrEquals, TokenType.OpMore,
TokenType.OpMoreOrEquals, TokenType.OpEquals, TokenType.OpNotEquals))
{
BinaryExpr expr = new BinaryExpr(firstTermToken);
expr.Left = left;
expr.SetOperatorFromToken(AcceptedToken);
expr.Right = ParseSimpleExpression();
return(expr);
}
return(left);
}
private Expression ParseSimpleExpression()
{
Token firstTermToken = CurrentToken;
ExprSign termSign = ExprSign.Plus;
if (Accept(TokenType.Minus, TokenType.Plus))
{
termSign = AcceptedToken.Type == TokenType.Minus ? ExprSign.Minus : ExprSign.Plus;
}
Expression left = ParseTerm();
left.Sign = termSign;
while (Accept(TokenType.Plus, TokenType.Minus, TokenType.OpOr))
{
BinaryExpr expr = new BinaryExpr(firstTermToken);
expr.SetOperatorFromToken(AcceptedToken);
expr.Left = left;
expr.Right = ParseTerm();
left = expr;
}
return(left);
}