New Ruby 1.9 hash syntax

Question

new_hash = {:simon => "Talek", :lorem => "Ipsum"}

can be replaced by

new_hash = {simon: "Talek", lorem: "Ipsum"}

Is there also a shorter way of writing

:on => :collection

Applying the same logic raises an error:

on: :collection

Update to provide more info:

In my routes.rb:

get 'detail', { on: :member } 

doesn't work. Neither does

get 'detail',  on: :member 

Error:

Exiting
SyntaxError: C:/Workspace/OE_11/CyberTrack_Rails3/config/routes.rb:23: 
  syntax error, unexpected ':'

      get 'detail', { on: :member }

or

Exiting
SyntaxError: C:/Workspace/OE_11/CyberTrack_Rails3/config/routes.rb:23: 
  syntax error, unexpected ':'

      get 'detail', on: :member

Answer 1

This works just fine for me:

def get(*args) p *args end

get 'detail', on: :member
# "detail"
# { :on => :member }

RUBY_ENGINE
# => jruby
JRUBY_VERSION
# => 1.6.6

EDIT: Now that you provided the error message, it looks like you are not running Ruby 1.9. The new hash syntax was introduced in Ruby 1.9, it doesn't work in older versions. You need to make sure that you are running Ruby 1.9, either by verifying that you are running the right Ruby implementation (e.g. YARV supports 1.9, MRI doesn't) or, if you are running a Ruby implementation that supports multiple language versions (e.g. JRuby) that you are passing the correct command line flags (e.g. jruby --1.9).

Answer 2

As others have mentioned, you need to use 1.9 to get this syntax to work. Setting the environment variable JRUBY_OPTS to --1.9 will ensure you are using the right ruby version.