[Jprogramming] NaN, p., and control structures

[Louis de Forcrand]

What about control structures treating _. as false?
I personally would make that an error, and I would also say that code that makes use of this should be considered bad style.

Louis

> On 29 Dec 2017, at 18:29, Henry Rich <henryhrich at gmail.com> wrote:
> 
> Surely not intended.  Put it on the bug list.
> 
> Henry Rich
> 
> On 12/29/2017 6:06 PM, Louis de Forcrand wrote:
>> On the Indeterminate vocabulary page of the dictionary it is written
>> 
>> The only ways to create _. are as follows:
>>    	direct entry of _.
>>    	".
>>    	3!:n
>>    	DLL call (database, LAPACK, etc.)
>> 
>> and
>> 
>> Primitives on arguments not containing _. signal NaN error instead of producing _. .
>> 
>> yet (in j64-805 on macOS 10.10.5)
>> 
>>    2 7 p.1e308j_
>> _.j_
>> 
>> This is very dangerous, as comparison with _. seems to yield _. and it also seems that control structures treat _. as false instead of signalling an error (which is in my opinion a very bad idea).
>> Are both these behaviours intended?
>> 
>> Thanks,
>> Louis
>> 
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