Re: [MacPerl] FNG

[Chris Nandor <pudge@pobox.com>]

At 15.50 -0500 1999.01.28, Vicki Brown wrote:
>At 21:20 -0500 1/27/99, Chris Nandor wrote:
>> At 19.51 -0500 1999.01.27, Vicki Brown wrote:
>>>As sayeth the Camel, container of all knowledge (p. 38)
>>>
>>>   While we might speak of a scalar as "containing" a number or a string,
>>>   scalars are essentially typeless; there's no way to declare a scalar of
>>>   type "number" or "string". Perl converts between the various subtypes as
>>>   needed, so you can treat a number as a string or a string as a number,
>>>   and Perl will do the Right Thing.
>>
>> We know, of course, this is not true, since these are different:
>>
>>   ~'1'
>>   ~1
>
>
>How does the fact that these are different (one has been forced to be
>a string, the other hasn't) make the statement from the Camel untrue?

It says there is no way to declare a scalar of type number or string.  If
that were the case, then these would not return different values.  A better
example:

  #!perl -wl
  $x = '1';  # declared as string
  print ~$x; # treated as string
  $x += 0;   # declared as a number
  print ~$x; # treated as number
  $x .= '';  # declared as string again
  print ~$x; # treated as string again

At least, this makes the Camel wrong as I read it.  But it seems clear to
me that these scalars are typed as strings and as numbers depending on how
you used it.  Else ~$x would always produce the same thing, since in every
case $x == 1 (and $x eq '1' :).

--
Chris Nandor          mailto:pudge@pobox.com         http://pudge.net/
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