Feature #12047: Set#=== (aliased to include?)

• Status: Closed
• Assignee: -
• Target version: -

[Phrogz (Gavin Kistner)]

Add Set#=== as an alias for Set#include? so that sets may be used in case statements:

require 'set'
GOOD_COMMANDS = Set[ :foo, :bar, :jim ]
BAD_COMMANDS  = Set[ :baz, :bax, :jam ]
ODD_COMMANDS  = Set[ :quux, :xyzzy ]

case my_command
  when GOOD_COMMANDS then puts "Yay!"
  when BAD_COMMANDS  then puts "Boo!"
  when ODD_COMMANDS  then puts "Whaa?"
end

[Phrogz (Gavin Kistner)]

• Subject changed from Set#=== to Set#=== (aliased to include?)

[sawa (Tsuyoshi Sawada)]

I think that is ad hoc. Splat could be used, just like with arrays.

case my_command
when *GOOD_COMMANDS then puts "Yay!"
when *BAD_COMMANDS  then puts "Boo!"
when *ODD_COMMANDS  then puts "Whaa?"
end

And one-time splatting would be also more efficient than calling include? each time.

[jonathanhefner (Jonathan Hefner)]

This was added in Ruby 2.5, so I think this issue can be closed.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed