/// <summary>
/// Process the term2 rule.
/// </summary>
/// <remarks>
///
/// term2 ::= '*' factor term2 |
/// '/' factor term2 |
/// {empty}
///
/// </remarks>
/// <returns>Parsed node.</returns>
protected virtual EvalNode ParseTerm2()
{
if (Tokeniser.Next(TokenType.Multiply))
{
EvalNode op = new EvalNodeBinaryOp(EvalNodeBinaryOp.BinaryOp.Multiply, ParseFactor(), Language);
EvalNode term2 = ParseTerm2();
if (term2 != null)
{
term2.Prepend(op);
}
return(op);
}
if (Tokeniser.Next(TokenType.Divide))
{
EvalNode op = new EvalNodeBinaryOp(EvalNodeBinaryOp.BinaryOp.Divide, ParseFactor(), Language);
EvalNode term2 = ParseTerm2();
if (term2 != null)
{
term2.Prepend(op);
}
return(op);
}
return(null);
}
/// <summary>
/// Parse the 'expression2' rule.
/// </summary>
/// <remarks>
///
/// expression2 ::= '+' term expression2 |
/// '-' term expression2 |
/// {empty}
///
/// </remarks>
/// <returns>Parsed node.</returns>
protected virtual EvalNode ParseExpression2()
{
if (Tokeniser.Next(TokenType.Plus))
{
EvalNode op = new EvalNodeBinaryOp(EvalNodeBinaryOp.BinaryOp.Add, ParseTerm(), Language);
EvalNode expr2 = ParseExpression2();
if (expr2 != null)
{
expr2.Prepend(op);
}
return(op);
}
if (Tokeniser.Next(TokenType.Minus))
{
EvalNode op = new EvalNodeBinaryOp(EvalNodeBinaryOp.BinaryOp.Subtract, ParseTerm(), Language);
EvalNode expr2 = ParseExpression2();
if (expr2 != null)
{
expr2.Prepend(op);
}
return(op);
}
return(null);
}
/// <summary>
/// Parse the 'term' rule.
/// </summary>
/// <remarks>
///
/// term ::= factor term2
///
/// </remarks>
/// <returns>Parsed node.</returns>
protected virtual EvalNode ParseTerm()
{
EvalNode factor = ParseFactor();
EvalNode term2 = ParseTerm2();
if (term2 != null)
{
term2.Prepend(factor);
return(term2);
}
else
{
return(factor);
}
}
/// <summary>
/// Parse the 'expression' rule.
/// </summary>
/// <remarks>
///
/// expression ::= term expression2
///
/// </remarks>
/// <returns>Parsed node.</returns>
protected virtual EvalNode ParseExpression()
{
EvalNode term = ParseTerm();
EvalNode expr2 = ParseExpression2();
if (expr2 != null)
{
expr2.Prepend(term);
return(expr2.Root);
}
else
{
return(term.Root);
}
}