Issue #6284 has been updated by printercu (Max Melentiev). matz (Yukihiro Matsumoto) wrote: > Considering the combination of OOP and FP, it seems a good idea to adding both forward and reverse combination of procs. So we pick Groovy way (adding `<<` and `>>` methods to `Proc`). What do you think about selecting only single operation? Here is Groovy example from provided link: ``` final times2 = { it * 2 } final plus1 = { it + 1 } final plus1_then_times2 = times2 << plus1 final times2_then_plus1 = times2 >> plus1 ``` It looks like `<<` is less intuitive and readable. I'm also really afraid of having chance to read something like `a >> b << c >> d`. ---------------------------------------- Feature #6284: Add composition for procs https://bugs.ruby-lang.org/issues/6284#change-73207 * Author: pabloh (Pablo Herrero) * Status: Open * Priority: Normal * Assignee: matz (Yukihiro Matsumoto) * Target version: ---------------------------------------- It would be nice to be able to compose procs like functions in functional programming languages: ```ruby to_camel = :capitalize.to_proc add_header = ->val {"Title: " + val} format_as_title = add_header << to_camel << :strip ``` instead of: ```ruby format_as_title = lambda {|val| "Title: " + val.strip.capitalize } ``` It's pretty easy to implement in pure ruby: ```ruby class Proc def << block proc { |*args| self.call( block.to_proc.call(*args) ) } end end ``` ---Files-------------------------------- 0001-proc.c-Implement-Proc-for-Proc-composition.patch (3.65 KB) 0002-proc.c-Implement-Method-for-Method-composition.patch (2.67 KB) 0003-proc.c-Support-any-callable-when-composing-Procs.patch (3.97 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=unsubscribe> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>