// - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
private static IExpression ParseAddExpression()
{
if (Check(FirstMultExp))
{
var exp = ParseMultExpression();
while (Check(new TokenSet(TokenType.Plus | TokenType.Minus)))
{
var opType = _currentToken.Type;
Eat(opType);
if (!Check(FirstMultExp))
{
throw new InvalidSyntaxException("Expected an expression after + or - operator");
}
var right = ParseMultExpression();
switch (opType)
{
case TokenType.Plus:
exp = new AddExpression(exp, right);
break;
case TokenType.Minus:
exp = new SubExpression(exp, right);
break;
default:
throw new UnexpectedBehaviorException("Expected plus or minus, got: " + opType);
}
}
return(exp);
}
throw new InvalidSyntaxException("Invalid expression");
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
private static IExpression ParseAddExpression()
{
if (Check(FirstMultExp))
{
var exp = ParseMultExpression();
while (Check(new TokenSet(TokenType.Plus | TokenType.Minus)))
{
var opType = _currentToken.Type;
Eat(opType);
if (!Check(FirstMultExp))
{
throw new InvalidSyntaxException("Expected an expression after + or - operator");
}
var right = ParseMultExpression();
switch (opType)
{
case TokenType.Plus:
exp = new AddExpression(exp, right);
break;
case TokenType.Minus:
exp = new SubExpression(exp, right);
break;
default:
throw new UnexpectedBehaviorException("Expected plus or minus, got: " + opType);
}
}
return exp;
}
throw new InvalidSyntaxException("Invalid expression");
}
