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Re: Why doesn't nconc change my variable?
From: |
Marcin Borkowski |
Subject: |
Re: Why doesn't nconc change my variable? |
Date: |
Sun, 05 Oct 2014 11:35:35 +0200 |
On 2014-10-05, at 03:59, Pascal J. Bourguignon wrote:
> Marcin Borkowski <mbork@wmi.amu.edu.pl> writes:
>
>> Hi list,
>>
>> I don't get it.
>
> () is actually read as the symbol nil.
> Symbols are symbols, and not cons cells.
> You cannot transform a symbol into a cons cell.
> It is impossible for any function to transform nil into a cons cell.
>
> And vice-versa, it is impossible to transform a cons cell into a symbol
> such as nil. This is the reason why you should also use setf when
> deleting elements from a list:
>
> (setf list (delete e list))
I still don't understand. What if I used (list) to generate an empty
list instead of () or nil? The results seem to be still the same.
Best,
--
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Adam Mickiewicz University
Re: Why doesn't nconc change my variable?, Pascal J. Bourguignon, 2014/10/05