Re: Output an alist from a function

[tomas]

On Mon, Sep 23, 2024 at 09:42:38PM +0000, Heime wrote:
> 
> I have an alist composed of keys and associated directory paths, and want 
> to output an alist made of the same keys with values being a validation flag.
> Perhaps the problem is the call to mapcar.  In the case of the hash table I 
> have
> to call output-table after the maphash.
> 
> (defun dirpath-validation (input-table-or-alist)
>   "Test validity of directory path for each key."
> 
>   (cond
> 
>       ((hash-table-p input-table-or-alist)
> 
>       ;; Make hash-table for output
>       (let ( (output-table (make-hash-table :test 'equal)) )
>         (maphash (lambda (key dirpath)
>                    (puthash key (not (file-directory-p dirpath)) 
> output-table))
>                  input-table-or-alist)
>         output-table))
> 
>       (t
>          (mapcar (lambda (entry)
>               (let ( (key      (car entry))
>                      (dirpath  (cdr entry)) )
>                 (cons key (not (file-directory-p dirpath)))) )
>             input-table-or-alist)) ))

I've some difficulties figuring out what your question is.

Is it that you want to write a function which "does the same"
as output-table does, but for alist?

Then we don't know what output-table does, so we can only guess.

Assuming it writes its content into a buffer, each entry on one
line, key and value separated by space, then this might do as a
rough prototype:

  (insert
    (mapc
      (lambda (k v) (format "%s %s\n) k v)
      input-table-or-alist))

Cheers
-- 
t

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