Re: my command line notes:

[ToddAndMargo]

On 03/15/2017 10:04 AM, Timo Paulssen wrote:

On 14/03/17 20:58, ToddAndMargo wrote:


#!/usr/bin/perl6

if not @*ARGS.elems > 0 { say "command line is empty"; exit 0; }

say "\@\*ARGS has " ~ @*ARGS.elems ~ " elements";
say "   \@\*ARGS  = <" ~ @*ARGS  ~ ">";
say "   \@\*ARGS.perl = <" ~ @*ARGS.perl ~ ">\n";

say "say in a loop:";
for @*ARGS.kv -> $indx, $Arg { say "   \@\*ARGS[$indx] = <$Arg>"; }



Please note that if you don't interpolate into a string anyway, you can
use '' instead of "" and you won't have to backslash stuff at all.


say '@*ARGS has ' ~ @*ARGS.elems ~ " elements";
say '   @*ARGS  = <' ~ @*ARGS  ~ ">";
say '   @*ARGS.perl = <' ~ @*ARGS.perl ~ ">\n";


But even with "" you don't have to backslash the @ and the * there. You
only would have to do that if you had a method call that includes
parenthesis or if you had a subscript after something that looks just
like an array variable. (these rules depend on the sigil, they are the
same for %-sigiled vars, but $-sigiled vars will interpolate much more
readily.)

timo@schmand ~> perl6 -e 'my @*things = "raindrops on roses",
"whiskers on kittens", "bright copper kettles";
say "@*things has @*things.elems() elements";
say "@*things = <@*things.Str()>";
say "@*things.perl = <@*things.perl()>\n";'
@*things has 3 elements
@*things = 
@*things.perl = <["raindrops on roses", "whiskers on kittens",
"bright copper kettles"]>

Hope that helps!
  - Timo



Hi Timo,

Thank you!  "" '' can be very helpful.  Very sweet example.
(one example worth 1000 words)

I tend to escape things and use regular quotes so I remember
what I have to escape and what I don't.  It is just a memory
crutch.

And I am going to have to look up @* variables, again.

-T


--
~~
Computers are like air conditioners.
They malfunction when you open windows
~~

Re: my command line notes:

[Timo Paulssen]

On 14/03/17 20:58, ToddAndMargo wrote:
> 
> #!/usr/bin/perl6
>
> if not @*ARGS.elems > 0 { say "command line is empty"; exit 0; }
>
> say "\@\*ARGS has " ~ @*ARGS.elems ~ " elements";
> say "   \@\*ARGS  = <" ~ @*ARGS  ~ ">";
> say "   \@\*ARGS.perl = <" ~ @*ARGS.perl ~ ">\n";
>
> say "say in a loop:";
> for @*ARGS.kv -> $indx, $Arg { say "   \@\*ARGS[$indx] = <$Arg>"; }
> 

Please note that if you don't interpolate into a string anyway, you can
use '' instead of "" and you won't have to backslash stuff at all.


say '@*ARGS has ' ~ @*ARGS.elems ~ " elements";
say '   @*ARGS  = <' ~ @*ARGS  ~ ">";
say '   @*ARGS.perl = <' ~ @*ARGS.perl ~ ">\n";


But even with "" you don't have to backslash the @ and the * there. You
only would have to do that if you had a method call that includes
parenthesis or if you had a subscript after something that looks just
like an array variable. (these rules depend on the sigil, they are the
same for %-sigiled vars, but $-sigiled vars will interpolate much more
readily.)

timo@schmand ~> perl6 -e 'my @*things = "raindrops on roses",
"whiskers on kittens", "bright copper kettles";
say "@*things has @*things.elems() elements";
say "@*things = <@*things.Str()>";
say "@*things.perl = <@*things.perl()>\n";'
@*things has 3 elements
@*things = 
@*things.perl = <["raindrops on roses", "whiskers on kittens",
"bright copper kettles"]>

Hope that helps!
  - Timo

Re: my command line notes:

[ToddAndMargo]

On 03/14/2017 01:37 PM, ToddAndMargo wrote:

On 03/14/2017 01:26 PM, Will Coleda wrote:

FYI

https://docs.perl6.org/language/functions#index-entry-MAIN


Thank you!


So far, I haven't gotten to creative:

my $DebugFlag = @*ARGS.elems;   # generate a crash report if > 0

Re: my command line notes:

[ToddAndMargo]

On 03/14/2017 01:26 PM, Will Coleda wrote:

FYI

https://docs.perl6.org/language/functions#index-entry-MAIN


Thank you!

Re: my command line notes:

[Will Coleda]

FYI

https://docs.perl6.org/language/functions#index-entry-MAIN

On Tue, Mar 14, 2017 at 3:58 PM, ToddAndMargo  wrote:
> Hi All,
>
> I wrote myself a little demonstration program on
> reading elements from the command line.  I thought
> it might be useful to others (DuckDuckGo is a bust
> on Perl 6 and the command line):
>
> -T
>
>
> Perl 6: command line parameters:
>
> 
> #!/usr/bin/perl6
>
> if not @*ARGS.elems > 0 { say "command line is empty"; exit 0; }
>
> say "\@\*ARGS has " ~ @*ARGS.elems ~ " elements";
> say "   \@\*ARGS  = <" ~ @*ARGS  ~ ">";
> say "   \@\*ARGS.perl = <" ~ @*ARGS.perl ~ ">\n";
>
> say "say in a loop:";
> for @*ARGS.kv -> $indx, $Arg { say "   \@\*ARGS[$indx] = <$Arg>"; }
> 
>
>
> $ ./CommandLineTest.pl6
> command line is empty
>
> $ ./CommandLineTest.pl6 a b c
> @*ARGS has 3 elements
>@*ARGS  = 
>@*ARGS.perl = <["a", "b", "c"]>
>
> say in a loop:
>@*ARGS[0] = 
>@*ARGS[1] = 
>@*ARGS[2] = 
>
>
> --
> ~~
> Computers are like air conditioners.
> They malfunction when you open windows
> ~~



-- 
Will "Coke" Coleda