:|┃ / tokyu rubykaigi 12

A tech talk at Tokyu RubyKaigi 12, featuring how to implement musical repeat sign :|┃ in Ruby, using continuation (callcc) which is a killer feature of Ruby.

Transcript

1. :|┃ TokyuRubyKaigi12 2018-07-29 ujihisa
2. :|| 反復記号
3. require 'continuation' class String def |(x) x.() end end def ┃ -> { $c.call($c) } end class Proc def |(_) $c = callcc {|c| c } end end $c ||= callcc {|c| c }
4. require 'さっきのやつ' puts 'before' %: :|┃ p 'after'
5. require 'さっきのやつ' puts 'before' %: :|┃ p 'after'
6. require 'さっきのやつ' puts 'before' (%: :).|(┃) p 'after'
7. require 'continuation' class String def |(x) x.() end end def ┃ -> { $c.call($c) } end class Proc def |(_) $c = callcc {|c| c } end end $c ||= callcc {|c| c }
8. require 'さっきのやつ' puts 'first' ┃|:"start\n".display puts 'before' %: :|┃ p 'after'
9. require 'さっきのやつ' puts 'first' ┃|:"start\n".display puts 'before' %: :|┃ p 'after'
10. require 'continuation' class String def |(x) x.() end end def ┃ -> { $c.call($c) } end class Proc def |(_) $c = callcc {|c| c } end end $c ||= callcc {|c| c }
11. :|┃ continuation便利 毎日使おう