RE: [External] : Exiting from mapc

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On Wednesday, January 1st, 2025 at 10:30 AM, Drew Adams <drew.adams@oracle.com> wrote:

> > > > How can I exit when encountering 'safg or 'nogo
> > > 
> > > As usual, wrap with a `catch', and` throw' to it whenever you like.
> > 
> > Does the catch statement belong before mapc?
> 
> 
> Yes - "wrap".
> 
> 
> (defun amazones-falkotr-kntlr (actm-seqr)
> (catch 'RTFM
> (mapc (lambda (...)
> <Do whatever, and `throw' any value,
> from anywhere here, to 'RTFM>)
> 
> actm-seqr))))
> 
> 1. `C-h f catch' 2. https://www.gnu.org/software/emacs/manual/html_node/elisp/Catch-and-Throw.html Learning to use` catch' and `throw' with code such as iteration is basic. And catch/throw is a building block for implementing other iteration etc. constructs. The Elisp code that Emacs provides so freely to you is a great place to learn about Elisp. Grep for` catch' there...
> 
> Here's a simple example:
> 
> (defmacro while-no-input (&rest body)
> "..."
> (declare (debug t) (indent 0))
> (let ((catch-sym (make-symbol "input")))
> `(with-local-quit
> (catch ',catch-sym
> (let ((throw-on-input ',catch-sym))
> (or (input-pending-p)
> (progn ,@body)))))))
> 
> Here's another:
> 
> (defun get-window-with-predicate (predicate &optional minibuf all-frames default)
> "..."
> (catch 'found
> (dolist (window (window-list-1
> (next-window nil minibuf all-frames)
> minibuf all-frames))
> (when (funcall predicate window)
> (throw 'found window)))
> default))

How can one get  the result of the throw?  With a let?
 
> The Elisp manual makes great bedtime reading.
> Time better spent than asking help-gnu-emacs,
> perhaps.