# Pypes **URL:** \ **Category:** Ruby\ **Created:** [March 27, 2008, 7:22pm UTC](https://www.ruby-forum.com/t/pypes/133102 "2008-03-27T19:22:08Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 7:22pm UTC](https://www.ruby-forum.com/t/pypes/133102/1 "2008-03-27T19:22:08Z")
[http://www.voidspace.org.uk/python/weblog/arch\_d7\_2008\_03\_22.shtml#e954](http://www.voidspace.org.uk/python/weblog/arch_d7_2008_03_22.shtml#e954) Nice example of what you can do with generators. Is this sort of thing doable efficiently in 1.9? martin ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 7:34pm UTC](https://www.ruby-forum.com/t/pypes/133102/2 "2008-03-27T19:34:33Z")
On Mar 27, 2008, at 1:20 PM, Martin DeMello wrote: > [http://www.voidspace.org.uk/python/weblog/](http://www.voidspace.org.uk/python/weblog/) > arch\_d7\_2008\_03\_22.shtml#e954 > > Nice example of what you can do with generators. Is this sort of thing > doable efficiently in 1.9? Don’t know if this meets the criteria, but [http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html) [http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html) Cheers Dave ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 7:46pm UTC](https://www.ruby-forum.com/t/pypes/133102/3 "2008-03-27T19:46:59Z")
On Thu, Mar 27, 2008 at 11:33 AM, Dave T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Don’t know if this meets the criteria, but > > [http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html) > [http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html) Yes, exactly what I had in mind. Very nice. martin ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 7:52pm UTC](https://www.ruby-forum.com/t/pypes/133102/4 "2008-03-27T19:52:16Z")
On Thu, Mar 27, 2008 at 11:33 AM, Dave T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > [http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2007/12/pipelines-using.html) > [http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html](http://pragdave.blogs.pragprog.com/pragdave/2008/01/pipelines-using.html) Tangentially, why did the trick of defining methods with the same name as classes, to delegate to Class.new, fall out of favour? ``` tripler = Transformer.new {|val| val * 3} ``` would read more nicely as ``` tripler = Transformer {|val| val * 3} ``` with def Transformer(x); Transformer.new(x); end I remember it being a commoner practice a few years ago. martin ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 8:56pm UTC](https://www.ruby-forum.com/t/pypes/133102/5 "2008-03-27T20:56:17Z")
On Mar 27, 12:20 pm, “Martin DeMello” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > [http://www.voidspace.org.uk/python/weblog/arch\_d7\_2008\_03\_22.shtml#e954](http://www.voidspace.org.uk/python/weblog/arch_d7_2008_03_22.shtml#e954) > > Nice example of what you can do with generators. Is this sort of thing > doable efficiently in 1.9? some\_date.filter1.filter2.action What is the advantage of data filters over method chaining in practical terms? What am I missing? Regards, Dan ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 9:24pm UTC](https://www.ruby-forum.com/t/pypes/133102/6 "2008-03-27T21:24:18Z")
Daniel B. wrote: > practical terms? What am I missing? > Apparently, PragDave’s filters read one entry at a time, on demand (like > unix pipes). Method chaining has to build a complete collection for each > step. ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 9:26pm UTC](https://www.ruby-forum.com/t/pypes/133102/7 "2008-03-27T21:26:04Z")
On Thu, Mar 27, 2008 at 6:51 PM, Martin DeMello [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > with def Transformer(x); Transformer.new(x); end > > I remember it being a commoner practice a few years ago. > > martin Some of us oldies still use it. But I seem to remember some people objected last time I suggested it (ruby-talk[160664]). Regards, Sean ---
**Author:** ![Martin\_DeMello](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/f17d59/32.png) [@Martin\_DeMello](https://www.ruby-forum.com/u/Martin_DeMello)\ **Post date:** [March 27, 2008, 9:44pm UTC](https://www.ruby-forum.com/t/pypes/133102/8 "2008-03-27T21:44:58Z")
Martin DeMello wrote: > ``` > tripler = Transformer {|val| val * 3} > > ``` > > with def Transformer(x); Transformer.new(x); end > > I remember it being a commoner practice a few years ago. > > martin It looks like a typo when there is no method name after (what looks like) a constant name. There’s also the cognitive load of deciding whether “Transformer.meth” is “send :meth to the result of method Transformer()” or “send :meth to the value of constant Transformer”. My brain knows it is the latter, but my eyes don’t. class T def self.meth; “T.meth” end def meth; “T#meth” end end def T; T.new; end p T.meth p T().meth p T.new.meth Quick, which one(s) are calling the class method, T#meth. But maybe that’s just me. As long as we’re playing in the global space, I’d define a lower case method, #transformer. Saves a keystroke, too.