[fpc-pascal] special numbers detected by val()

[Joao Morais]

Marc Santhoff wrote:
> I want to read in text files containing matrix data. The data is
> organized in rectangular manner, but some places are not valid because
> they are from physical measurements at places that are not reachable by
> any instrument.
> 
> In this data files I have to use a convention to detect this invalid
> spots.
> 
> My idea was to uses the string "NaN" or the like because anything else
> would narrow the range of input values (e.g. using -999 or similar for
> expressing the special case). If val could handle this itself, I'd not
> have to write any parsing code.

You can implement your own data type (eg as a class) and include some 
flags as IsNull, IsEmpty, etc.

--
Joao Morais