[I'm extremely new to CL.  Please excuse, but feel free to correct, any
inaccuracies in my terminology.  Thanks.]

Hi,

I'm trying to create a function that, given a name of a new array as an
argument, creates a new array of a default length.  This is so that I
can use one function to easily setup the array initially, and then I
want to create other functions that abstract the process of editing the
various elements inside of the array.  Here is the code I'm
using:

(defun create-array(new-array)
  (setf new-array (make-array 4 :initial-element 'blank))
  (print new-array))

Then I call it using:

(create-array 'name-of-array)

When the 'print' fires from inside the function, everything looks fine.
But i I try this:

(print name-of-array)

I get the following:

*** - EVAL: variable NAME-OF-ARRAY has no value

I'm using CLISP.  I'm not sure what I'm doing wrong.  What I want is for
the newly created array to be accessable outside of the function.  I
tried using defparameter, but that didn't seem to work either.  Any
pointers are GREATLY appreciated.

The problem is that the SETF only modifies the local variable
NEW-ARRAY that disappears when the function returns.

This can be solved in several ways.  You will have to judge for
yourself which solution fits your needs best.

The first solution is to make a function that returns an array with
the required properties:

: (defun create-array1 ()
:   (make-array 4 :initial-element 'blank))
:
: (setf name-of-array (create-array1))
:
: (print name-of-array)

The second solution is to make a macro that does the job.

: (defmacro create-array2 (new-array)
:   `(setf ,new-array (make-array 4 :initial-element 'blank)))
:
: (create-array2 name-of-array)
:
: (print name-of-array)

The third solution is to modify the symbol-table entry for this given
symbol.  This is closest to the original, but generally not
considered "nice".  However, if this is what you need...

: (defun create-array3 (new-array)
:   (setf (symbol-value new-array)
:         (make-array 4 :initial-element 'blank))
:   (print new-array))
:
: (create-array3 'name-of-array)
:
: (print name-of-array)

Hope that helped.

Stig Hemmer,
Jack of a Few Trades.

  It seems that you are still writing in some other language.

| I'm trying to create a function that, given a name of a new array as an
| argument, creates a new array of a default length.

  This is not how we do things in Common Lisp.

| This is so that I can use one function to easily setup the array
| initially, and then I want to create other functions that abstract the
| process of editing the various elements inside of the array.

  The function should simply return the object you have created, and your
  caller should bind it.  The reason for this is that you cannot pass a
  reference to any sub-object storage location into which your called
  function can store the value.  This is quite crucial to understand if you
  are going to write Common Lisp in Common Lisp.

| (defun create-array(new-array)
|   (setf new-array (make-array 4 :initial-element 'blank))
|   (print new-array))
|
| Then I call it using:
|
| (create-array 'name-of-array)

  I suggest you do this, instead:

(defun create-array (new-array)
  (make-array 4 :initial-element 'blank))

  and in your caller do

(let ((name-of-array (create-array)))
  ...)

  or, if this is a global resource:

(defparameter *name-of-array* (create-array))

| I'm using CLISP.  I'm not sure what I'm doing wrong.

  Basically, you are still writing in some other language.  You have to let
  go of your desire to think you know what you are doing and start over as
  a novice before you can actually know what you are doing.

| What I want is for the newly created array to be accessable outside of
| the function.  I tried using defparameter, but that didn't seem to work
| either.  Any pointers are GREATLY appreciated.

  I hope the above is more helpful than receiving advice on how you should
  accomplish what you should not want to do.  Good luck learning Common
  Lisp and unlearning bad habits from other languages.  As you have seen
  here in another response, not all those who think they know Common Lisp
  have unlearned their old bad habits and may still think that helping
  people with their explicit problem is better than trying to find and
  solve their underlying problem.

  Not at all.  I was referring to a fellow Norwegian who is permanently
  clueless, yet very "helpful", so people get much further astray than they
  were to begin with.  With luck, you thought it was you because you have
  been relieved of his "helpful" response.  It is important to realize when
  somebody would be hurt by being helped to achieve what they ask for, and
  _not_ to hurt people who ask for help in hurting themselves.  Some of the
  clueless "good samaritans" out there never seem to learn this.  Since
  this particular cretin is one of those who go totally bananas when he is
  not allowed to wear his halo after helping to hurt someone, I find it
  vital to newsgroup peace not to name him, so at least he has a choice of
  not responding and thus keeping the mystery of his identity instead of
  making it obvious that he does not even understand when to shut up.  So,
  in summary, no, it was not you I referred to.

(defun create-array ()
   (make-array 4 :initial-element 'blank))

(may not have been an obvious typo to the OP)

        Cool!
        I even printed this! :-)