[ruby-core:21923] Re: [Feature #1122] request for: Object#try

Hi,

2009/2/7 David A. Black <[e-mail]>:
> Hi --
>
> On Sat, 7 Feb 2009, Yusuke ENDOH wrote:
>
>> Hi,
>>
>> 2009/2/7 Narihiro Nakamura <[e-mail]>:
>>>
>>> Feature #1122: request for: Object#try
>>> http://redmine.ruby-lang.org/issues/show/1122
>>>
>>> Author: Narihiro Nakamura
>>> Status: Open, Priority: Normal
>>>
>>> Hi.
>>>
>>> Object#try is new feature of rails2.3.
>>>
>>> http://guides.rubyonrails.org/2_3_release_notes.html
>>>
>>> http://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/try.rb
>>> http://ozmm.org/posts/try.html
>>>
>>> Matz said: "OK, good name is the last problem."
>>>
>>> Anyone has better name?
>>
>>
>> Interesting.  I think `try' is good enough for me as non-native.
>>
>> But why does it take Object#send-like interface?
>> I dislike Object#send because complex modifications are needed:
>>
>>  foo.bar(baz) -> foo.send(:bar, baz)
>>
>> I have to type "send(:", move the cursor, delete "(", and type ", ".
>> What a pain!
>>
>>
>> Of course, it can't be helped in the case of Object#send.
>> But there is no reason for Object#try to follow it.
>> I prefer:
>>
>>  foo.bar(baz) -> foo.try.bar(baz)
>>
>> because it is much simpler (only to insert ".try")
>
> I don't think that's a big issue, because you'd probably either use
> try or not, and not change it back and forth.


I don't expect that we will do it *back and forth*, but I think
that *forth* will often be needed.

In addition, I feel that the two styles are oddly different in
spite of almost the same meanings.
It is allowable for Object#send because there is no other way
and such a reflection feature is not so often used.  But, try
will be routinely used, and thus should not emulate such a odd
style unless it really has to.


>> For example:
>>
>>  x = nil; p x.try + 1 #=> nil
>>  x = 100; p x.try + 1 #=> 101
>
> I prefer the send-like way. "try" without an argument doesn't make
> sense to me here; it leaves me asking, "Try *what*?" The idea that
> "try" in the abstract means "self or a BasicObject that returns nil
> for missing methods" isn't a good fit, I think.


Hmm...


BTW, some time ago, if I'm correct, nobu suggested a new syntax:

  foo.?bar(baz)

as a syntax sugar to:

  foo.respond?(:bar) ? foo.bar(baz) : nil

.
I prefer it too.  What do you think about it?

-- 
Yusuke ENDOH <[e-mail]>