Feature #4172

Named arguments/parameters support

Added by rosenfeld (Rodrigo Rosenfeld Rosas) over 1 year ago. Updated 4 months ago.

[ruby-core:33774]
Status:Rejected Start date:12/20/2010
Priority:Low Due date:
Assignee:matz (Yukihiro Matsumoto) % Done:

0%
Category:-
Target version:-

Description

It is usual in the Ruby community to use the idiom

def method(options={})
  param1, param2 = options.values_at(:param1, :param2) # or {param1: 'default1', param2: 2}.collect{|k, v| options[k] || v }
  ...
end

instead of

def method(param1, param2)
  ...
end

Perl 6 supports named arguments (or parameters) out-of-the-box. Suppose the following method (not valid Ruby actually):

def tag(tag_name, :content(''), :attributes({}), :closing_tag(true))
  ...
end

It would be great if this could be called as

hr = tag('hr', closing_tag -> false, attributes -> {style: 'color: blue'})

It think it should be even possible to call it like

tag(tag_name: 'div', content: 'Ruby is getting even more awesome with this feature!')

I think it is much more legible than 

tag('hr', '', {}, false)

or than using an 'options' hash parameter.

Is there any reasons why Ruby doesn't support named parameters as part of the syntax?

History

#1
Updated by rosenfeld (Rodrigo Rosenfeld Rosas) over 1 year ago

Sorry, I meant:

tag(tag_name -> 'div', content -> 'Ruby is getting even more awesome with this feature!')

#2
Updated by matz (Yukihiro Matsumoto) over 1 year ago

Hi,

In message "Re: [ruby-core:33774] [Ruby 1.9-Feature#4172][Open] Named arguments/parameters support"
    on Mon, 20 Dec 2010 08:13:36 +0900, Rodrigo Rosenfeld Rosas <redmine@ruby-lang.org> writes:

|Feature #4172: Named arguments/parameters support
|http://redmine.ruby-lang.org/issues/show/4172

Ruby 2.0 will have named arguments.  The spec is bit different from
your proposal though.

							matz.

#3
Updated by rosenfeld (Rodrigo Rosenfeld Rosas) over 1 year ago

Great! Is there any place I can see the spec?

Thank you and best regards!

Rodrigo

#4
Updated by shyouhei (Shyouhei Urabe) about 1 year ago

  • Status changed from Open to Assigned

#5
Updated by naruse (Yui NARUSE) 7 months ago

  • Project changed from ruby-trunk to 14
  • Category deleted (core)
  • Target version deleted (3.0)

#6
Updated by naruse (Yui NARUSE) 7 months ago

  • Project changed from 14 to ruby-trunk

[ruby-core:42414]#7
Updated by kosaki (Motohiro KOSAKI) 4 months ago

  • Status changed from Assigned to Rejected
Current trunk (for 2.0) has a keyword argument feature. Please look at and give us comments. Thanks.

[ruby-core:42438]#8
Updated by rosenfeld (Rodrigo Rosenfeld Rosas) 4 months ago

I wouldn't say this was rejected, but implemented/accepted instead ;)

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