From: Michael Lucas-Smith <s3225202@...>
Date: 2002-01-20T18:33:52+09:00
Subject: Re: Proc.class vs yield : propose keyword procs

Charles D Hixson wrote:

> On Friday 18 January 2002 15:59, you wrote:
> 
>>That's a slippery slope to smalltalk ;-).  I suppose you could if
>>you were required to give an empty arglist like [|| ...] when
>>there weren't any arguments so there would be no confusion with
>>an Array literal.  But if you were going to change the language
>>why not only allow one of the two currently allowed syntaxes for
>>a block ({|| ...}, or do || ... end), and use the other to
>>instantiate an actual Proc object (and I'm not necessarily
>>advocating this, but it might add more visual distinction).  The
>>best I can offer you is a band-aid, lambda instead of proc (a
>>much nicer word don't you think?).
>>
>>Alexander Schofield
>>
>>Michael Lucas-Smith wrote:
>>
>>>I see what you're saying. I suggest that perhaps it was a
>>>mistake to re-use the same syntax between hash and block.
>>>Obviously that cannot be fixed now, but perhaps [] can be used
>>>to represent a proc so that:
>>>
>>>proc { ... }
>>>and:
>>>[ ... ]
>>>
>>>mean the same thing.
>>>
>>>Michael
>>>
> Possibly a new reserved word:  procs
> The meaning would be that all of the remaining arguments were 
> procs. Thus:
> def method (procs a, b, c)
> 
> This would be in error if, e.g., c were not a proc, and one could 
> also have
> def method (some, bunch, of, arguments, procs a, b, c)
> 
> There is a question in my mind as to whether or not one should be 
> able to specify an indefinite number of procedure arguments, but I 
> don't see how one could have both multiple procedure agruments and 
> an indefinite number of non-procedural arguments.  I don't see why 
> one would want to, but perhaps one should plan for the necessity.  
> In that case the syntax would change to:
> def method (some, arguments) procs (a, b, c)
> 
> This could get messy if one were using in-line code rather than 
> procedure variables, but that's more the fault of the in-line code 
> than anything else.
> 
> 

Sorry, I don't see any use to this. That's adding typing information to 
parameters of a method. That's like specifying you want the first two 
arguments to be strings, the next argument to be an integer and the last 
three arguments to be procs.

Michael