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On Sat, Aug 22, 2009 at 7:38 PM, Caleb Clausen <caleb / inforadical.net>wrote:

> Yehuda Katz wrote:
>
>> I'd like to propose that we add the following syntax for procs in Ruby:
>>
>>  x   contents }
>>  x   |y| contents }
>>    { contents }.should raise_error(Exception)
>>    call_method({ proc_1 }, { proc_2 }, { proc_3 })
>>  Essentially, any use of {} that was not a Hash would become a proc.
>> Effectively, this includes all use of {} that produces a SyntaxError at the
>> moment ({} remains the equivalent of Hash.new). I suggested this to
>>
>
> How do you disambiguate this case:
>
>  { foo bar baz }
>
> which could be parsed 2 ways:
>  { foo(bar) baz } #a hash
> or
>  { foo(baraz) }   #a block


Things that currently don't parse are fine to become blocks. I'd be worried
about a case that currently parsed fine as a Hash but might be expected to
be parsed as a block if this feature existed. Can you think of any?


>
>
> (Note, however, that the first snippet is currently a syntax error....)
>
> I think Rick DeNatale raises a good point too.
>
> Ruby 1.9 used to have a feature like this, but it was taken out, I think
> out of fear of the ambiguities it creates. As a user, I like this feature a
> lot. But as an implementor of ruby's syntax, I've learned to dread
> ambiguities; they just make my life hard. That's not necessarily a reason
> not to do it, but I would like the ambiguities to be very carefully
> considered and explicitly mapped out.
>
>


-- 
Yehuda Katz
Developer | Engine Yard
(ph) 718.877.1325

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<br><br><div class="gmail_quote">On Sat, Aug 22, 2009 at 7:38 PM, Caleb Clausen <span dir="ltr">&lt;caleb / inforadical.net&gt;</span> wrote:<br><blockquote class="gmail_quote"tyle="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<div class="im">Yehuda Katz wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I&#39;d like to propose that we add the following syntax for procs in Ruby:<br>
<br>
  ¨Β γοξτεξτσ ύΌβς  ¨Β όωγοξτεξτσ ύΌβς  ¨Β γοξτεξτσ ύ®σθουμδ ςαισείεςςος¨Εψγεπτιοξ©ΌβςΎ
  ¨Βαμμίνετθοδ¨ϋ πςογί± ύ¬ πςογί² ύ¬ πςογί³ ύ©ΌβςΎ
  ¨Βσσεξτιαμμωαξυσοζ ϋύ τθατ χαξοΘασθ χουμβεγονε πςογΕζζεγτιφεμω¬ τθισ ιξγμυδεσ αμυσοζ ϋύ τθατ πςοδυγεσ ΣωξταψΕςςοατ τθνονεξτ ¨ϋςεναιξτθερυιφαμεξτ οζ Θασθ®ξεχ©® συηηεστετθισ το ΌβςΎ
</blockquote>
<br></div>
How do you disambiguate this case:<br>
<br>
  ¨Β ζοβὦητβαύΌβς<br>
which could be parsed 2 ways:<br>
  ¨Β ζοο¨βας© ½¦ητβα£α θασθΌβςΎ
or<br>
  ¨Β ζοο¨βας½¦ητ»βαϊ© £α βμογλΌ―βμογλρυοτεΎΌδιφΎΌβςΎΌ―διφΎΌδιφΎΤθιξησ τθατ γυςςεξτμδο³Ή»παςσαςζιξε το βεγονε βμογλσΙ¦£³Ή»βε χοςςιεαβουγασε τθατ γυςςεξτμπαςσεδ ζιξε ασ Θασθ βυνιηθβε εψπεγτεδ το βε παςσεδ ασ βμογιζ τθισ ζεατυςεψιστεδ® Γαωοτθιξοζ αξωΏΌ―διφΎ

<div>/div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><br>
<br>
(Note, however, that the first snippet is currently a syntax error....)<br>
<br>
I think Rick DeNatale raises a good point too.<br>
<br>
Ruby 1.9 used to have a feature like this, but it was taken out, I think out of fear of the ambiguities it creates. As a user, I like this feature a lot. But as an implementor of ruby&#39;s syntax, I&#39;ve learned to dread ambiguities; they just make my life hard. That&#39;s not necessarily a reason not to do it, but I would like the ambiguities to be very carefully considered and explicitly mapped out.<br>


<br>
</blockquote></div><br><br clear="all"><br>-- <br>Yehuda Katz<br>Developer | Engine Yard<br>(ph) 718.877.1325<br>

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