merb

Comments and changes to this ticket

• 

  Brian Mitchell June 6th, 2008 @ 05:21 PM

  • → Title changed from “Hash#only adds nil keys” to “Hash#only adds nil values for keys”
• 

  Michael Klishin (antares) June 7th, 2008 @ 12:57 AM

  I think if you use only on Hash, you know what keys are in that hash. Not sure what behavior would be more intuitive.

• 

  Brian Mitchell June 7th, 2008 @ 02:23 AM

  The specific case is where you want to filter not extract. So consider a case where I have some options which may or may not be set on some hash that I want to pass on to another function.

      def f1(opts = {})
        f2(opts.only(:key1, :key1))
      end
  

  In this case, if makes sense to avoid nil values which may or may not mean something depending on f2. For example, a common case where behavior might change is Hash#has_key?.

  The behavior I would expect is as follows:

      {}.only(:key) #=> {}
      {:key => nil}.only(:key) #=> {:key => nil}
      {:key => 42}.only(:key) #=> {:key => 42}
  

• 

  Brian Mitchell June 7th, 2008 @ 02:29 AM

  I just checked another implementation of this function in Rails (aka Hash#slice like Array#slice). They return similar results to my last comment.

• 

  Brian Mitchell June 7th, 2008 @ 02:56 AM

  I've made a really simple implementation with tests over on github at: http://github.com/binary42/merb-...

  Commit: 962a75fda82f3ecbfa8ca85cf9843fe8f9d55786

• 

  Brian Mitchell June 10th, 2008 @ 06:54 PM

  • no changes were found...

  • hash_only_key_check.diff 1.4 KB
• 

  Michael D. Ivey (ivey) June 12th, 2008 @ 12:39 AM

  • → Assigned user changed from “” to “Michael D. Ivey (ivey)”
  • → State changed from “new” to “resolved”

  Applied in 33a25d088ddf4f6931a509f8dee712d48bb045cd

  I hope no one was relying on the (broken) previous behavior