internal static ExpressionNode ParseExpression(string line, int startIndex)
{
if (startIndex >= line.Length)
{
return(null);
}
var oper = ParseOperator(line, startIndex);
if (oper == null)
{
return(null);
}
ReducibleNode left = ParseNumeric(line, oper.NextIndex);
if (left == null)
{
left = ParseExpression(line, oper.NextIndex);
if (left == null)
{
return(null);
}
}
ReducibleNode right = ParseNumeric(line, left.NextIndex);
if (right == null)
{
right = ParseExpression(line, left.NextIndex);
if (right == null)
{
return(null);
}
}
var index = SkipWhiteSpace(line, right.NextIndex);
return(new ExpressionNode(oper, left, right, index));
}
public ExpressionNode(OperatorNode oper, ReducibleNode left, ReducibleNode right, int nextIndex) : base(nextIndex)
{
this.Operator = oper;
this.Left = left;
this.Right = right;
}