The task is as follows: depending on the passed function value, with the help of perform either the addition of the list elements or the multiplication of the list elements. those.

apply func(x) '(1 2 3 4)

if x = 1, then the result is 10, if x = 2, then 24

Here is what I did:

I define the func function

 (defun func_(x) (cond ((eql 1 x)(plus))(eql 2 x)(TIMES))

then try to call apply

 (apply func_(1) '(1 2 3 4))

but the compiler gives an error

Error: The variable FUNC_ is unbound.
Fast links are on: do (si :: use-fast-links nil) for debugging
Error signalled by EVAL.
Backtrace: EVAL
Broken at SYSTEM :: GCL-TOP-LEVEL.

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1 answer 1

There are no plus and TIMES functions in my interpreter (more precisely, TIMES was previously defined differently), but I immediately see a strange thing for you - you are trying to call func_ not in the style of LISP. Try replacing your

 (apply func_(1) '(1 2 3 4))

on

 (apply (func_ 1) '(1 2 3 4))

I also decided to rewrite your func_ function using + and *, it turned out the following:

 (defun func_(x) (cond ((eql 1 x)(lambda (&rest ns) (apply '+ ns)))((eql 2 x)(lambda (&rest ns) (apply '* ns)))))