[ANN] Junctions for Ruby1.9 (Lab419::functional-0.1.2)

Hi list Lab419::functional contains an implementation of Perl6's junctions now http://rubyforge.org/frs/?group_id=3824&release_id=33503 Enjoy Junctions A pure Ruby implementation of Junctions as planned for Perl6. [1] Junctions are composite expressions that reply to methods as would their elements. E.g. any(1, 2, 3) > 2 --> true [ 1, 3, 5 ].all.odd? --> true none( 1 ).zero? --> true all() == nil --> true any() == nil --> false A popular use case is if any( "--help", "-?", "-h" ) == param then usage Junctions can be constructed by either * using the module methods any, all, none and one of Lab419::Junctions or * by using junction methods of enumerables (1..3).all > 0 or * by including Lab419::Junctions For details please see the references below. [1] http://en.wikipedia.org/wiki/Perl_6#Junctions http://search.cpan.org/dist/Perl6-Junction/lib/Perl6/Junction.pm http://www.perl.com/pub/a/2003/07/29/exegesis6.html?page=4 http://www.programmersheaven.com/2/Perl6-FAQ-Junctions

Hello, Robert Dober wrote: > Lab419::functional contains an implementation of Perl6's junctions now It works fine, but I received warning message with -v option of ruby. $ cat t.rb require 'lab419/functional/junctions' $ /usr/local/trunk/bin/ruby -v t.rb ruby 1.9.2dev (2009-04-17) [i686-linux] /usr/local/trunk/lib/ruby/site_ruby/1.9.1/lab419/functional/junctions/base.rb:83: warning: method redefined; discarding old one? /usr/local/trunk/lib/ruby/site_ruby/1.9.1/lab419/functional/junctions/base.rb:91: warning: method redefined; discarding old none? regards Masaki Suketa

On Sat, Apr 18, 2009 at 3:04 AM, Masaki Suketa <masaki.suketa@nifty.ne.jp> wrote: > Hello, > > Robert Dober wrote: > >> Lab419::functional contains an implementation of Perl6's junctions now > > It works fine, but I received warning message with -v option of ruby. > > $ cat t.rb > require 'lab419/functional/junctions' > > $ /usr/local/trunk/bin/ruby -v t.rb > ruby 1.9.2dev (2009-04-17) [i686-linux] > /usr/local/trunk/lib/ruby/site_ruby/1.9.1/lab419/functional/junctions/bas= e.rb:83: > warning: method redefined; discarding old one? > /usr/local/trunk/lib/ruby/site_ruby/1.9.1/lab419/functional/junctions/bas= e.rb:91: > warning: method redefined; discarding old none? > > =A0regards > =A0Masaki Suketa > Thank you for reporting this, I will look into it right now. Robert

> Enjoy > > Junctions > > A pure Ruby implementation of Junctions as planned for Perl6. [1] Pretty sweet! Did you look into how complex it would be to implement autothreading, like in Perl 6, too? :)

On Sat, Apr 18, 2009 at 4:58 PM, David Palm <dvdplm@gmail.com> wrote: >> Enjoy >> >> Junctions >> >> A pure Ruby implementation of Junctions as planned for Perl6. [1] > > Pretty sweet! > > Did you look into how complex it would be to implement autothreading, lik= e in Perl 6, too? > > :) No but that's a nice idea. Cheers R. Si tu veux construire un bateau ... Ne rassemble pas des hommes pour aller chercher du bois, pr=E9parer des outils, r=E9partir les t=E2ches, all=E9ger le travail=85 mais enseigne aux gens la nostalgie de l=92infini de la mer. If you want to build a ship, don=92t herd people together to collect wood and don=92t assign them tasks and work, but rather teach them to long for the endless immensity of the sea. -- Antoine de Saint-Exup=E9ry

On Sat, Apr 18, 2009 at 8:58 AM, David Palm <dvdplm@gmail.com> wrote: >> Enjoy >> >> Junctions >> >> A pure Ruby implementation of Junctions as planned for Perl6. [1] > > Pretty sweet! > > Did you look into how complex it would be to implement autothreading, like in Perl 6, too? > You should check out Ara T. Howard's threadify gem -- very similar to autothreading. Blessings, TwP

On Apr 17, 2009, at 11:17 PM, Robert Dober wrote: > E.g. > > any(1, 2, 3) > 2 --> true > [ 1, 3, 5 ].all.odd? --> true > none( 1 ).zero? --> true > all() == nil --> true > any() == nil --> false The examples you gave are equivalent to [ 1, 2, 3 ].any? { |e| e > 2 } [ 1, 3, 5 ].all? { |e| e.odd? } ![ 1 ].any? { |e| e.zero? } [].all? { |e| e == nil } [].any? { |e| e == nil } What advantages does junctions in Ruby provide over #any? and #all? ? Regards, Denis -- Denis Defreyne denis.defreyne@stoneship.org

On Sat, Apr 18, 2009 at 11:38 PM, Denis Defreyne <denis.defreyne@stoneship.org> wrote: > On Apr 17, 2009, at 11:17 PM, Robert Dober wrote: > >> E.g. >> >> =A0any(1, 2, 3) > 2 =A0 =A0 --> true >> =A0[ 1, 3, 5 ].all.odd? --> true >> =A0none( 1 ).zero? =A0 =A0 =A0--> true >> =A0all() =3D=3D nil =A0 =A0 =A0 =A0 --> true >> =A0any() =3D=3D nil =A0 =A0 =A0 =A0 --> false > > The examples you gave are equivalent to > > =A0 =A0 =A0 =A0[ 1, 2, 3 ].any? { |e| e > 2 } > =A0 =A0 =A0 =A0[ 1, 3, 5 ].all? { |e| e.odd? } > =A0 =A0 =A0 =A0![ 1 ].any? { |e| e.zero? } > =A0 =A0 =A0 =A0[].all? { |e| e =3D=3D nil } > =A0 =A0 =A0 =A0[].any? { |e| e =3D=3D nil } > > What advantages does junctions in Ruby provide over #any? and #all? ? They are an abstraction of the code blocks, if you look at streams, the second concept implemented in Lab419::functional we have exactly the same pattern, delay is nothing more than a lambda. As a matter of fact the main pleasure I have got from releasing code in Ruby is that Ruby does all the work and I can get the compliments, well I cannot because you have pointed out that I have not done anything. Thank you very much ;) ok seriously now: I believe that this kind of abstraction is useful, makes code shorter and even more readable. Is it worth a package? Well maybe not, but what are you going to tell a perl6 guru if he asks you if Ruby got Junctions? (Proud in Ruby was indeed a key motivation, maybe that is bad, I dunno ) Look at this example: if a_set.any > b_set.all then would be if a_set.any?{ | x | b_set.all?{ | y | x > y } } then I kind of prefer to maintain code written in the first style. Cheers Robert

On Apr 18, 2009, at 4:38 PM, Denis Defreyne wrote: > On Apr 17, 2009, at 11:17 PM, Robert Dober wrote: > >> E.g. >> >> any(1, 2, 3) > 2 --> true >> [ 1, 3, 5 ].all.odd? --> true >> none( 1 ).zero? --> true >> all() == nil --> true >> any() == nil --> false > > The examples you gave are equivalent to > ![ 1 ].any? { |e| e.zero? } Or: not [1].include? 0 > [].all? { |e| e == nil } Or: a = [] a.nitems == a.size > [].any? { |e| e == nil } Or: a.nitems > 0 Ruby 1.9's Enumerable#none?() and Enumerable#one?() also help out with tests like this. James Edward Gray II

On Apr 19, 2009, at 4:19 AM, Robert Dober wrote: > Look at this example: > if a_set.any > b_set.all then > would be > if a_set.any?{ | x | b_set.all?{ | y | x > y } } then > > I kind of prefer to maintain code written in the first style. I imagine I would just do: if a_set.max > b_set.max # ... end James Edward Gray II

On Sun, Apr 19, 2009 at 4:27 PM, James Gray <james@grayproductions.net> wro= te: > I imagine I would just do: > > =A0if a_set.max > b_set.max > =A0 =A0# ... > =A0end If #<=3D> is defined I would do the same, but that is not necessarily the case. ">" might implement something where ! ( !(a>b) -> b>a) as e.g. superset, subset relationships. If you are against such redefinitions, please read the example as follows: if a_set.any.superset?( b_set.all ) then I wanted to make it clear that Junctions can be combined and thus become a more powerful abstraction over relations. Cheers Robert --=20 Si tu veux construire un bateau ... Ne rassemble pas des hommes pour aller chercher du bois, pr=E9parer des outils, r=E9partir les t=E2ches, all=E9ger le travail=85 mais enseigne aux gens la nostalgie de l=92infini de la mer. If you want to build a ship, don=92t herd people together to collect wood and don=92t assign them tasks and work, but rather teach them to long for the endless immensity of the sea. -- Antoine de Saint-Exup=E9ry

On 4/19/09, Robert Dober <robert.dober@gmail.com> wrote: > > Look at this example: > if a_set.any > b_set.all then > would be > if a_set.any?{ | x | b_set.all?{ | y | x > y } } then Or, for the main case where this comparison makes sense: if a_set.max > b_set.max