Re: DBIish: Why can't I interpolate variable holding database name?

[James E Keenan]

On 05/01/2016 09:12 AM, Mathieu Gagnonn wrote:


Hello James,

You can try :database($db)
Look at this http://design.perl6.org/S02.html#Adverbial_Pair_forms
I've found it very useful!


James E Keenan writes:


Yesterday I made my first attempt at using any library in a Perl6
program -- specifically, DBIish.

The following succeeded in establishing a connection to a Postgresql
database named 'hierarchy' on the same disk as Perl6:

#
$ cat dbiish_connect.pl6
#!/usr/bin/env perl6
use DBIish;

my $dbh = DBIish.connect("Pg", :database);

say "Database: connection ", ($dbh.ping ?? "established" !! "not
established");

$ perl6 dbiish_connect.pl6
Database: connection established
#

Since I have several different Postgresql databases on disk, I want to
be able to store a DB's name in a variable, then have DBIish.connect
interpolate that variable while establishing a connection.  I tried:

#
$ cat dbiish_connect_dynamic.pl6
#!/usr/bin/env perl6
use DBIish;

my $db = 'hierarchy';
my $dbh = DBIish.connect("Pg", :database<$db>);

say "Database $db: connection ", ($dbh.ping ?? "established" !! "not
established");
#

But I only got this error output:

#
$ perl6 dbiish_connect_dynamic.pl6
DBDish::Pg: Can't connect: FATAL:  database "$db" does not exist
   (1)
in block  at
/home/jkeenan/rakudo-star/share/perl6/site/sources/3EA876C6AC912AF3692CEF8EEF5E9033C03F7507
(DBIish) line 41
in any  at
/home/jkeenan/.perl6/precomp/D7820A4EF6D97B780F45CAC4B50C4E6E59589690.1462056119.68849/3E/3EA876C6AC912AF3692CEF8EEF5E9033C03F7507
line 1
in method connect at
/home/jkeenan/rakudo-star/share/perl6/site/sources/C2BC378F86912AB748EF3CF51FBE6E3AE0CFE0EA
(DBDish::Pg) line 79
in method connect at
/home/jkeenan/rakudo-star/share/perl6/site/sources/3EA876C6AC912AF3692CEF8EEF5E9033C03F7507
(DBIish) line 45
in block  at dbiish_connect_dynamic.pl6 line 5
#

I also tried:

#
$ cat dbiish_connect_dynamic_2.pl6
#!/usr/bin/env perl6
use DBIish;

my $db = 'hierarchy';
my $dbh = DBIish.connect("Pg", ":database<$db>");

say "Database $db: connection ", ($dbh.ping ?? "established" !! "not
established");
#

But that gave me a different error:

#
$ perl6 dbiish_connect_dynamic_2.pl6
Too many positionals passed; expected 2 arguments but got 3
in method connect at
/home/jkeenan/rakudo-star/share/perl6/site/sources/3EA876C6AC912AF3692CEF8EEF5E9033C03F7507
(DBIish) line 29
in block  at dbiish_connect_dynamic_2.pl6 line 5
#

Why does variable interpolation not work here?  What part is my doing
something wrong?  What part is a limitation in the DBIish library?

Thank you very much.
Jim Keenan



Thanks; that worked:

#
cat dbiish_connect_dynamic_3.pl6
#!/usr/bin/env perl6
use DBIish;

my $db = 'hierarchy';
my $dbh = DBIish.connect("Pg", :database($db));

say "Database $db: connection ", ($dbh.ping ?? "established" !! "not 
established");


$ perl6 dbiish_connect_dynamic_3.pl6
Database hierarchy: connection established
#

Re: A practical benchmark shows speed challenges for Perl 6

[James E Keenan]

On 03/30/2016 04:11 PM, yary wrote:

On Wed, Mar 30, 2016 at 3:20 PM, Elizabeth Mattijsen  wrote:

Thanks for your thoughts!

I’ve implemented $*DEFAULT-READ-ELEMS in 
https://github.com/rakudo/rakudo/commit/5bd1e .

Of course, all of this is provisional, and open for debate and bikeshedding.





Yary, if you feel there's a need for this functionality in Perl *5* as 
well, please file a bug ticket via perlbug.


Thank you very much.
Jim Keenan

Re: 'split': differences between Perl5 and Perl6

[James E Keenan]

On 02/27/2016 08:38 PM, Brandon Allbery wrote:




[...] is what used to be (?:...), and <[...]> is what used to be [...].
Regexes have changed a *lot*, and you will really need to learn how they
work now; just hoping that things work just like perl 5 will not work.



My apologies for being a Perl6 beginner.

'split': differences between Perl5 and Perl6

[James E Keenan]

I am trying to understand the differences in the way the 'split' 
function works between Perl5 and Perl6.


Consider this string:

#
$str = q|This is a string to be split|;
#

Let's suppose I wish to split this string on the multi-character 
delimiter string 'tri'.  The results are the same in both languages.


#
# Case 1
$ perl -e 'my ($str, @rv);$str = q|This is a string to be split|; @rv = 
split(q|tri|, $str); print "<$_>" for @rv; print "\n";'


#
# Case 2
$ perl6 -e 'my ($str, @rv);$str = q|This is a string to be split|; @rv = 
split(q|tri|, $str); print "<$_>" for @rv; print "\n";'


#

Now let's suppose that in Perl5 I wish to split the string on a pattern 
which is the character class /[tri]/.  I get:


#
# Case 3
$ perl -e 'my ($str, @rv);$str = q|This is a string to be split|; @rv = 
split(/[tri]/, $str); print "<$_>" for @rv; print "\n";'

<><>
#

The result is a list of strings which do not contain any of 't', 'r' or 
'i'.  Where two of the delimiters occurred consecutively in the original 
string, I get an empty string -- except that empty strings at the end of 
the list are dropped.


Now let's run the same code in Perl6:

#
# Case 4
$ perl6 -e 'my ($str, @rv);$str = q|This is a string to be split|; @rv = 
split(/[tri]/, $str); print "<$_>" for @rv; print "\n";'


#

I'm surprised to get exactly the same output I got in both languages 
when my delimiter was the multi-character string 'tri'.  The '[' and ']' 
characters do not seem to indicate "character class" at all.  It's as if 
'/[...]/' magically turns into 'q|...|'.  What am I not grasping here?


One more case:  When, in Perl6, I surround the brackets with angle 
brackets, I get somewhat more expected behavior:


#
# Case 5
$ perl6 -e 'my ($str, @rv);$str = q|This is a string to be split|; @rv = 
split(/<[tri]>/, $str); print "<$_>" for @rv; print "\n";'

<><><><>
#

I get something very similar to Case 3, which was written in Perl5, 
viz., a list of strings which do not contain any of 't', 'r' or 'i'. 
Where two of the delimiters occurred consecutively in the original 
string, I get an empty string -- including at the end of the original 
string.  So, does that mean that, in Perl6, to split a string on a 
character class, I have to always indicate (via the angle brackets) that 
the character class is a list?


Thank you very much.
Jim Keenan

Re: Confused about rakudobrew and Rakudo Star

[James E Keenan]

On 02/03/2016 10:48 PM, Brandon Allbery wrote:

On Wed, Feb 3, 2016 at 10:30 PM, James E Keenan <jk...@verizon.net> wrote:


I am evidently confused as to the relationship, if any, between the
'rakudobrew' utility and the Rakudo::Star distribution.



In short: rakudobrew is for the folks who want to track the rapid
development of Rakudo. Star is for folks who want something stable in order
to play with the language, and includes the Task::Star ecosystem. As Star
was cut earlier today, it's based on the rakudo that was current earlier
today (and still fairly current as there haven't been many commits in the
past few hours).

It's more or less the difference between a Python or Perl 5 release, and
installing either from git HEAD. rakudobrew builds from HEAD; Star is a
release, which happens to be close to HEAD at the moment because it was
just created. HEAD will keep moving; Star will stay stable for a while
(used to be monthly, but they're considering releasing less often now)
before the next release.



So, to clarify:  If I want to get this week's release of Rakudo Star on, 
say, Linux, I have to download this tarball:


http://rakudo.org/downloads/star/rakudo-star-2016.01.tar.gz

... and build from source -- correct?  I cannot use rakudobrew for 
Rakudo Star -- correct?


Thank you very much.
Jim Keenan

Confused about rakudobrew and Rakudo Star

[James E Keenan]

I am evidently confused as to the relationship, if any, between the 
'rakudobrew' utility and the Rakudo::Star distribution.


Several weeks ago, when it became apparent that there would be delays in 
the release of a Rakudo Star distribution with the "Christmas" release 
in it, I executed the following commands to install Rakudo Perl 6.


$ rakudobrew install moar
$ rakudobrew install panda
$ panda install Task::Star

IIRC, I found these instructions at several locations, including this 
helpful blog post:


http://friedo.com/blog/2016/01/exploring-perl-6-up-and-running

The results:

[$ which perl6
/home/jkeenan/.rakudobrew/bin/perl6

$ perl6 -v
This is Rakudo version 2015.12-235-g172a92b built on MoarVM version 
2015.12-29-g8079ca5 implementing Perl 6.c.


And off I went to learn Perl 6.

Today, I saw Tobias Leich's message on this list, "Announce: Rakudo Star 
Release 2016.01", as well as Coke's blog post here: 
http://blogs.perl.org/users/coke/2016/02/rakudo-perl-6-compiler---2016011-released.html


So, I thought, oh good, now I can upgrade.  I repeated the above 
commands, with mixed results.  On the one hand, the first two commands 
ran without incident.  But when I said 'perl6 -v', I got the same Rakudo 
version as several weeks ago.  So it appears I didn't upgrade at all.


On the other hand, when I ran 'panda install Task::Star', I got this 
inelegant output:


#
$ panda install Task::Star
==> Fetching Task::Star
==> Building Task::Star
==> Testing Task::Star
==> Installing Task::Star
Task::Star:ver<*>:auth<>:api<> already installed
  in block  at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/C6FEA515A97C45ED8F92BCF5038BA028C9CE9CC0 
line 61
  in sub indir at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/5AEF9DA5AE15E5AB5CB2ADB58A455E007FA7839E 
line 20
  in method install at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/C6FEA515A97C45ED8F92BCF5038BA028C9CE9CC0 
line 42
  in method install at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/9036849E1656E91211D00AB4530B81D29A7D6E82 
line 161
  in method resolve at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/9036849E1656E91211D00AB4530B81D29A7D6E82 
line 234
  in sub MAIN at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/resources/76CD539C815A33F2891D2EF3D6D96B1081567AD1 
line 18
  in block  at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/resources/76CD539C815A33F2891D2EF3D6D96B1081567AD1 
line 150


Actually thrown at:
  in method install at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/C6FEA515A97C45ED8F92BCF5038BA028C9CE9CC0 
line 44
  in method install at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/9036849E1656E91211D00AB4530B81D29A7D6E82 
line 161
  in method resolve at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/sources/9036849E1656E91211D00AB4530B81D29A7D6E82 
line 234
  in sub MAIN at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/resources/76CD539C815A33F2891D2EF3D6D96B1081567AD1 
line 18
  in block  at 
/home/jkeenan/.rakudobrew/moar-nom/install/share/perl6/site/resources/76CD539C815A33F2891D2EF3D6D96B1081567AD1 
line 150

#

So, I'm confused as to whether I have any version of "Rakudo Star" at 
all.  My guess is that I've actually simply built, via rakudobrew, Perl6 
on Moar twice.  Is that correct?


Thank you very much.
Jim Keenan

Re: Needed: Rakudo Star with 6.c Christmas Perl 6 release

[James E Keenan]

On 01/25/2016 08:49 AM, Will Coleda wrote:

FYI,

http://blogs.perl.org/users/coke/2016/01/perl-6c-christmas-rakudo-star-coming-soon.html

We hope to have an R* release out in the next two weeks. Thanks for
your patience.



Thanks for the update!

jimk

Needed: Rakudo Star with 6.c Christmas Perl 6 release

[James E Keenan]

Today, I posted on the ny.pm mailing list an announcement that I will 
attempt to organize a Perl 6 Beginners study group in New York City.


I have been advised that for an introductory-level group, the Rakudo 
Star release would be the way to go.  However, when I went here:


  http://rakudo.org/how-to-get-rakudo/

... I read this:

"NOTE: the Rakudo Star with 6.c Christmas Perl 6 release is not yet
 available. Check back soon or try one of the older versions."

This is what, back in the day, we used to call a 'bummer'.  We have 
people -- including non-Perl programmers -- excited about Perl 6 -- but 
we don't have the easy on-ramp.


Is there a timeline for the release of a Rakudo Star with 6.c?

Thank you very much.
Jim Keenan

Re: Parrot Developer Summit Q1 2011 date

[James E Keenan]

On May 4, 2011, at 1:37 AM, Christoph Otto wrote:


Hi all,

Thanks to those who filled out the doodle to indicate your  
availability for the next Parrot Developer Summit.  The slots with  
the fewest conflicts were at the same time on different weeks.   
I've closed the doodle poll and marked Saturday the 14th at 1PM UTC


But the dates below suggest that what you really meant was probably:   
Saturday the 14th at *11PM* (2100) UTC -- right?




US Pacific: Saturday 14th, 2PM
US NY: Saturday 14th, 5PM
Paris: Saturday 14th, 11PM
Beijing: Sunday 15, 5AM
Sydney: Sunday 15, 7AM