Re: dynamic vs. static typing

[Pascal Costanza <address@hidden>]

Paul F. Dietz wrote:
> Scott McKay wrote:
> 
>> No, no, no.  In Lisp, all parameters are passed by "object
>> reference" (*).  Some of these objects are mutable, so you
>> can change "parts" of them.  Integers happen to be immutable,
>> so there's no part of it you can change.
> 
> 
> However, in Common Lisp, a conforming implementation is allowed
> to copy numbers or characters at any time, so no conforming program
> may depend on their object identity being preserved.  The
> form (EQ X X) needn't evaluate to a true value if X has
> a number or character value.

...but if (EQ X Y) evaluates to true then you can be sure that it is the 
same value even in the case of numbers and characters. Sometimes, this 
is all you need.


Pascal

-- 
Pascal Costanza               University of Bonn
mailto:costanza@web.de        Institute of Computer Science III
http://www.pascalcostanza.de  Römerstr. 164, D-53117 Bonn (Germany)