Re: Difference between cons and dot

[Arsen Arsenović]

Hi,

Heime <heimeborgia@protonmail.com> writes:

> Am adding an elemnt to an alist using either the cons or dot method.
> Have noticed that with cons I do not need to call list 
>
> Thusly 
>
> (push (cons kfrz lnum) tema-lugar)
>
> rather than
>
> (push '(cons kfrz lnum) tema-lugar)
>
> But with the dot method I have to use 
>
> (push '(kfrz . lnum) tema-lugar)
>
> and not 
>
> (push (kfrz . lnum) tema-lugar)
>
> What is the reason for this difference ?

'cons' is a primitive function.  (cons a b) produces a cons cell "(a
. b)".  "(a . b)" is a value.  Hence, 'cons' has to be called.  As (a
. b) can't be called, it should be quoted, hence '(a . b).

This is actually not a divergence, really; it's consistent with the rest
of the language.

[NOTE: not sure if I got the nomenclature right.. but the reasoning is
 correct: cons has to be called, (a . b) does not.]

Have a lovely day!
-- 
Arsen Arsenović

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