Re: Q: how to turn a list of symbols into a function?

Subject: Re: Q: how to turn a list of symbols into a function?
From: Erik Naggum <erik@naggum.net>
Date: 30 Oct 2000 12:34:08 +0000
Newsgroups: comp.lang.lisp
Message-ID: <3181898048463480@naggum.net>

* Rainer Joswig <joswig@corporate-world.lisp.de>
| It is simply a notation for lists:
| 
| (list '+ pi pi)
| 
| is the same as:
| 
| `(+ ,pi ,pi)
| 
| You can think of it as follows:
| 
| In (list '+ pi pi) you have write the list constructing function
| (here LIST) and you have to quote the constants (here the symbol +).
| 
| In `(+ ,pi ,pi) you write a list template and everything is constant
| - except in the places after the minus characters - so you are
| unquoting (-> forcing the evaluation at these places). So it is kind
| of opposite from the above.

  Except that the result of the backquote form is to be treated as a
  constant.  The list structure may not be modified as it might be
  shared with other list structures.

  (list ...) constructs a list at run-time.
  `(...) constructs at least parts of the list at read-time.

#:Erik
-- 
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