Feature #17315: Hash #transform

• Status: Open
• Assignee: -
• Target version: -

[dsisnero (Dominic Sisneros)]

Add new methods to transform or transform! both the keys and the values of a hash.
#7793

h = {'name' => 'dominic ', 'email' => 'dominic.mail.com '}
h.transform!{|k,v| [k.to_sym, v.strip]}
h # => {name: 'dominic', email: 'dominic.mail.com'}

[marcandre (Marc-Andre Lafortune)]

• Status changed from Open to Closed

You'll be happy to hear that this is exactly what to_h does already.

[marcandre (Marc-Andre Lafortune)]

• Status changed from Closed to Open

I'll reopen this, as you are asking for a mutating version of to_h.

[sawa (Tsuyoshi Sawada)]

• Description updated (diff)

[sawa (Tsuyoshi Sawada)]

• Description updated (diff)

[sawa (Tsuyoshi Sawada)]

marcandre (Marc-Andre Lafortune) wrote in #note-2:

I'll reopen this, as you are asking for a mutating version of to_h.

It might be strange to have transform! as the destructive counterpart to to_h. Perhaps, the naming should be Hash#to_h!? Wait. That looks even more strange.

[marcandre (Marc-Andre Lafortune)]

I didn't suggest anything, as I don't see a good name, and I don't see the appeal of this method:

• it can not be more efficient than update + to_h
• there's not a frequent usecase that I know of
• seems like avoidable mutation
• to_h! would be strange (conversion + mutation...?)

[dsisnero (Dominic Sisneros)]

to_h works for me even though it is unintuitive a name for monadic mapping a hash. I wish we had a common name function name in Enumerable for monadic mapping that would return the same Class that we map over.