RE: COMPLETING-READ Problem

[Drew Adams]

> While trying to implement a family of SQL identifier search functions,
> I want to offer tab completion to previously searched SQL identifiers
> -- besides builtin history functionality binded to M-p. For this
> purpose, I try to use COMPLETING-READ. Here's the related code
> snippet:
> 
> (defvar searched-sql-items nil
>   "Association list of previously searched SQL items.")
> 
> (defun make-local-searched-sql-items ()
>   "Creates per-buffer SEARCHED-SQL-ITEMS association list."
>   (make-local-variable 'searched-sql-items))
> 
> (add-hook 'sql-mode-hook 'make-local-searched-sql-items)
> 
> (defun search-sql-table (table-name)
>   "Search for specified TABLE-NAME in the current buffer."
>   (interactive
>    (let ((previously-searched-tables (assoc 'table searched-sql-
> items)))
>      (list
>       (completing-read
>        (if previously-searched-tables
>            (format "Table name (default: %s): "
>                    (first previously-searched-tables))
>          "Table name: ")
>        previously-searched-tables)))
>    ;; Insert specified TABLE-NAME to SEARCHED-SQL-ITEMS.
>    (let ((previously-searched-tables (assoc 'table searched-sql-
> items)))
>      (setf (assoc 'table searched-sql-items)
>            ;; Move TABLE-NAME to top.
>            (cons table-name (remove table-name previously-searched-
> tables))))
>    ;; Search table.
>    (search-forward (format "CREATE TABLE %s" table-name))))
> 
> But for some reason, function doesn't work. (Does nothing during
> execution.) I tried to place a (warn "TABLE-NAME: %s" table-name) just
> after (interactive ...) block, but there doesn't appear anything in
> the *Messages* buffer. Any ideas?

You pass `completing-read' an empty TABLE argument: you never fill
`previously-searched-tables', so it is nil.

And you never add any alist entry (table . <something) to
`searched-sql-items'. See
http://www.groupsrv.com/computers/about240758.html.

You need to think about or debug your code piece by piece.