[plt-scheme] Local function definition

Sorry; my last post was dumb (and has typos).  This makes more sense.

(define (connect-to)
   (let ((a (display "Server Address: "))
         (ip (read-line))
         (b (display "Port:"))
         (port (read)))
     (tcp-connect ip port)))

rac

On Jan 12, 2004, at 4:35 PM, Richard Cleis wrote:

>  For list-related administrative tasks:
>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>
> What's about the following?
>
> (define (connect-to-server-1)
>   (let ((ip (read-line))
>         (port (read)))
>     (display "Server address: ")
>     (display "Port: "))
>     (tcp-connect ip port))
>
> To me, define'itions are for the outermost scope since the language 
> isn't intended to see inside functions anyway.  That's why I like it.  
> Perhaps there is an ordering issue with the above.  But I doubt it, 
> since let* will even let you put all of the code in the let-list:
>
> (define (connect-to-server-2)
>   (let* ((ip-read (read-line))
>          (ip ip-read)
>          (port (read))
>          (waste-not (display "Server address: "))
>          (want-not (display "Port: "))
>          (have-not (tcp-connect ip port)))
>   'do-nothing-body))
>
> If the assignments weren't made in order, then ip wouldn't know where 
> to get ip-read.
>
> rac
>
>
> On Jan 12, 2004, at 8:53 AM, Dor Kleiman wrote:
>
>>   For list-related administrative tasks:
>>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>>
>> I think so too; for instance, the following example (or anything with
>> write-read) is quite much simpler with co-mingling:
>> ; with co-mingling
>> (define (connect-to-server)
>>   (display "Server address: ")
>>   (define ip (read-line))
>>   (display "Port: ")
>>   (define port (read))
>>   (tcp-connect ip port))
>>
>> ; without co-mingling
>> ; example 1
>> (define (connect-to-server-1)
>>   (display "Server address: ")
>>   (let ([ip (read-line)])
>>     (display "Port: ")
>>     (let ([port (read)])
>>       (tcp-connect ip port))))
>>
>> ; example 2
>> (define (prompt p f)
>>   ; displays the prompt p and runs f (e.g. read or read-line)
>>   (display p)
>>   (f))
>> (define (connect-to-server-2)
>>   (define ip (prompt "Server address: " read-line))
>>   (define port (prompt "Port: " read))
>>   (tcp-connect ip port))
>>
>> ; example 3
>> (define (connect-to-server-3)
>>   (define ip (begin (display "Server address: ")
>>                     (read-line)))
>>   (define port (begin (display "Port: ")
>>                       (read)))
>>   (tcp-connect ip port))
>>
>> All examples need more input checking, etc., but they are just 
>> examples
>> of a simple thing becoming so complex...
>> -----Original Message-----
>> From: Robby Findler [mailto:robby at cs.uchicago.edu]
>> Sent: Monday, January 12, 2004 4:13 PM
>> To: Dor Kleiman
>> Cc: Guillaume Marceau; plt-scheme at po.cs.brown.edu
>> Subject: RE: [plt-scheme] Local function definition
>>
>> At Mon, 12 Jan 2004 11:29:13 +0200, "Dor Kleiman" wrote:
>>> Which brings me to something I've always wondered about: Why can't 
>>> you
>>> commingle definesand expressions?
>>
>> Because the language is defined that way. I'm not sure of the 
>> rationale
>> of the designers on this particular point. It is certainly possible to
>> allow such co-mingling (units, modules, and classes in mzscheme all
>> allow it). I, for one, think that internal definitions would be better
>> off if co-mingling were allowed.
>>
>> Robby
>