Hi Tim,
Here
>safe-close: func [p[port!]][if p [close p]]
you are insisting that the argument to safe-close must be a value of
datatype port!, [ p [port!] ]. Therefore you get an error message, whenever
you pass a value that is not of type port!.
In contrast, here
>safe-close: func [p][if p <> [] [close p]]
you are not declaring a type restriction on the values passed to
safe-close, [ p ]. Accordingly, safe-close does not complain that the value
is not of type port!.
Confusing? Not really.
At 08:22 AM 5/23/00 -0800, you wrote:
>Hi Ladislav:
> Yes, your code works for me. But I wrote a function
>as follows:
>safe-close: func [p[port!]][if p [close p]]
>lets say
>dufus: none
>safe-close dufus
>generates
>Script Error: safe-close expected p argument of type: port
>HOWEVER:
>if I write
>safe-close: func [p][if p <> [] [close p]]
>dufus: []
>safe-close dufus
>I get no error message.
>:>) Duh!! I know I have lots to learn yet.
>Thanks
>Tim
>>Sorry, I don't understand. For me your code works:
>>
>>>> dufus-pointer: none
>>== none
>>>> either equal? dufus-pointer none [][close dufus-pointer]
>>>>
>>
>> Ladislav
>>
>>
>
>
>
;- Elan >> [: - )]
