Re: understanding backquote

[Pascal J. Bourguignon]

Olaf Rogalsky <olaf.rogalsky@aol.de> writes:

>>> I have problems in understanding the semantics of backquote. Consider
> ...
>> (info "(elisp) Backquote")
>
> Yes, I read that, but the manual does not make it entirly clear, at
> which time comma expressions are evaluated: at read or at compile-time:
>
>   9.4 Backquote
>   ...
>   The special marker ‘,’ inside of the argument to backquote indicates a
>   value that isn’t constant. The Emacs Lisp evaluator evaluates the
>   argument of ‘,’, and puts the value in the list structure:
>   ...

Also, consider: '`,(+ 1 2) --> (\` (\, (+ 1 2)))
this shows how this backquote is read.  
In emacs lisp \` is a macro.


-- 
__Pascal Bourguignon__                 http://www.informatimago.com/
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