On Thu, Aug 27, 2020 at 1:40 PM ToddAndMargo via perl6-users
<perl6-us...@perl.org <mailto:perl6-us...@perl.org>> wrote:
On 2020-08-27 13:28, Tobias Boege wrote:
> On Thu, 27 Aug 2020, ToddAndMargo via perl6-users wrote:
>> To pick out particular lines:
>> $ cat Lines.txt | raku -e '.say for lines()[3,2,5]'
>> Line 3
>> Line 2
>> Line 5
>>
>> If it is, it is buried somewhere.
>>
>> And what goes inside the ()? That may seem like a dumb
>> remark (especially since I live and die in Top Down and
>> know very well what the () does) but it is a common mistake
>> I make with lines is forgetting the () when using the [].
>>
>
> How does that mistake manifest? I cannot see a way in which omitting
> the sub call parentheses in code like that could possibly lead to
some
> different behavior.
>
Here is does not:
$ cat Lines.txt | raku -e '.say for lines[3,2,5]'
Line 3
Line 2
Line 5
And I am having trouble reproducing the issue. Would
help my point, no? I will write back if I find it.
Usually I forget my mistakes as soon as I figure out
the right way to do things.
Now this is getting weird!
$ cat Lines.txt | raku -ne 'my $x=$_; say $x; for $x.lines()[3,2,5] ->
$i {say $i;}'
Line 0
Nil
Nil
Nil
Line 1
Nil
Nil
Nil
Line 2
...
On 2020-08-27 14:12, yary wrote:
You have an extra semicolon in there -" say $x; for" -
so what happens is for each line
1. it runs "say $x" and thus prints "Line 0" the first time through,
since it had read "Line 0" only
2. Then it runs "say $i" for each of $x.lines()[3,2,5] - but $x is only
"Line 0" so it says 3 x "Nil"
3. Repeat for "Line 1", etc
-y
But I wanted the extra `;` in there. I wanted to see
before and after.
