[Chicago-talk] removing line from file.

[Wiggins d'Anconia]

Wiggins d'Anconia wrote:
> Jim Thomason wrote:
> 
>>> # ignore first 4 lines
>>>     next if 1 .. 4;
>>
>>
>>
>> I believe that should be:
>>
>> next if $. == 1 .. $. == 4;
>>
>> 1..4 won't work, since both 1 and 4 are true values, it never hits the 
>> 'next'.
>>
>> -Jim....
> 
> 
> This is very odd. Your catch seems ok, but the reasoning seems odd. 
> C<1..4> is a range, 1 and 4 specifically never enter the picture. And 
> regardless the next would *always* get hit rather than 'never' because 
> they *are* true. In this case does the 'if' get a list (1,2,3,4), or 4 
> (meaning the number in the list) or 4 (the last entry in the range)?? Or 
> does it really work where Perl does some magic not looping over the 
> range except at each iteration of the outer 'while' (which seems 
> impossible)? 

Which of course if this was a lesser language it would be, but since it 
is Perl it isn't impossible, only difficult ;-).... Checking perldoc 
perlop reveals that the range knows its context, and in scalar context 
all kinds of fun stuff can occur.... Specifically the original should 
work....

http://danconia.org

  Not to mention the whole binding order of .. and ==, which
> wouldn't that turn the above into:  C<if $. == (1 .. $.) == 4;>, or do I 
> have my highest/lowest backwards again?
> 
> Of course, we could just opt for the less silly,
> 
> next if $. < 5;
> 
> :)
>