[plt-scheme] Please help test version 359.100

hufflen jean-michel skrev:
>>From hufflen at lifc.univ-fcomte.fr  Tue Nov 14 18:11:42 2006
>> (...)
> 
>>   The notion of *unspecified value* is ambiguous. It may be:
>>   - any value, possibly chosen randomly,
>>   - no value, or (why not?) several values as Scheme functions may return
>> multiple values.
> 
>    After checking, the situation is more ambiguous than I was thinking. Let us
> consider:
> 
> [0] (for-each write '())
> [1] (define checking-for-each (for-each write '()))
> [2] (define checking-zero-value (values))
> [3] checking-for-each
> [4] checking-zero-value
> [5] (eq? checking-for-each (for-each write '()))
> 
>    PLT accepts [0], [1], but not [2], although [0] and [1] do not result in a
> value. 

Note that PLT repl doesn print void. So 1 and 3 does produce a value.

; [1]
 > (display (for-each write '()))
#<void>

; [1]

 > (eq? (for-each write '())
        (void))
#t


; [3] yields the same as [1], that is, no value.

 > (display checking-for-each)
#<void>


See section 3.1 in the MzScheme Language Manual.

-- 
Jens Axel Søgaard