Re: lambda, ->, haskell, and so on

Hi --

On Thu, 8 May 2008, ara howard wrote:

>
> On Apr 30, 2008, at 9:26 PM, Dave Thomas wrote:
>> This is one of those e-mails that I know from the start to be futile, 
>> but...
>> 
>> For a while now, the
>>
>>    -> (params) { block }
>> 
>> syntax in Ruby 1.9 has bothered me, but I've never been sure why. Today, 
>> while playing with pure, it struck me. The '->' sequence is in an 
>> unexpected place. Having played with some functional languages, I'm used to 
>> lambdas being written
>> 
>> \ params -> block
>
> i like the '->' because it suggests very nice multi-block syntax
>
> filter(
>
> :before -> { buf.upcase },
>
> :after -> { bug.downcase }
>
> )
>
> which doesn't work now, of course, but it can't be that far off.

Consider the big picture, though :-) That's a pretty specific use-case
(I don't mean it's unheard-of, but it's not likely to account for the
majority of literal lambdas), and if you're right that it's going to
be possible, then I guess we'd also have:

   m(:one "string", :two "other")

and

   m(:one [1,2,3], :two [2,3,4])

In other words, not every case will have an arrow built into it, and I
don't think it's worth the line noise and possibly odd semantics of
the arrow, in other contexts, just so one class of argument can look
like it's being pointed to in argument lists.


David

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