" 'while' ...will stop when it encounters a false line--typically an
empty line or '0' ".
Wasn't that the point of p5's defined
while ( defined(my $line = <> ) ) {
or (previously lexified '$val'):
print "$val\n" while defined($val = pop(@ary));
________________________________
From: William Michels via perl6-users <[email protected]>
Sent: Tuesday, January 21, 2020 1:08 PM
To: Trey Harris <[email protected]>; perl6-users <[email protected]>
Cc: Andrew Shitov <[email protected]>; Curt Tilmes <[email protected]>; Joseph
Brenner <[email protected]>; ToddAndMargo <[email protected]>; yary
<[email protected]>; Elizabeth Mattijsen <[email protected]>; [email protected]
<[email protected]>
Subject: Re: Using raku/perl6 as unix "cat"....
Good answers, all. Thanks to everyone for contributing.
For anyone who wants a golfed "cat" replacement, command line
arguments can give you shorter code:
mydir$ perl6 -e '.say for lines' ab_cd.txt
a
b
c
d
mydir$ perl6 -ne '.say' ab_cd.txt
a
b
c
d
mydir$ # below two single quotes as empty arg:
mydir$ perl6 -pe '' ab_cd.txt
a
b
c
d
mydir$
Finally, a question about the 'get' docs, which use 'while' as an
example for the (IO::CatHandle) 'get' method. The docs say
"(IO::CatHandle) method get: Returns a single line of input from the
handle... . Returns Nil when there is no more input. ... ." And,
"(IO::Handle) routine get: Reads a single line of input from the
handle... . Returns Nil, if no more input is available... ." See:
https://docs.raku.org/routine/get
Should a different example other than "while/get" be used on the docs
page? Or should some of the comments Yary made regarding "while/get"
be incorporated into the docs--so programmers can be warned about
truncating their output on blank lines with "while/get"? Yary, from
Jan. 18th:
" 'while' ...will stop when it encounters a false line--typically an
empty line or '0' ".
Best Regards, Bill.
On Mon, Jan 20, 2020 at 4:13 PM Trey Harris <[email protected]> wrote:
>
> On Mon, Jan 20, 2020 at 19:03 Trey Harris <[email protected]> wrote:
>>
>> On Mon, Jan 20, 2020 at 02:59 William Michels via perl6-users
>> <[email protected]> wrote:
>>>
>>> Hi Yary (and Todd),
>>>
>>> Thank you both for your responses. Yary, the problem seems to be with
>>> "get". I can change 'while' to 'for' below, but using 'get' raku/perl6
>>> actually returns fewer lines with "for" than it did with "while":
>>
>>
>> If you want to do line-oriented input, use `.lines` with `for`; it returns
>> something `for` can iterate over.
>
>
> Sorry, in a setting where a handle isn’t the context, I meant `lines`, not
> `.lines`, though I was referring _to_ a thing called `.lines`, the multi
> method. I don’t think we’ve all yet agreed on how multis that can be called
> as plain routines should be referred to in umbrella term. `.lines` is more
> “correct”, but it’s less likely to actually work without understanding more,
> which is a strange conundrum for documentation.
>
> Trey
