Re: Making alist that executes multiple commands

[Stephen Berman]

On Mon, 25 Nov 2024 21:18:28 +0000 Heime <heimeborgia@protonmail.com> wrote:

> Sent with Proton Mail secure email.
>
> On Tuesday, November 26th, 2024 at 9:05 AM, Stephen Berman
> <stephen.berman@gmx.net> wrote:
>
>> On Mon, 25 Nov 2024 20:45:22 +0000 Heime heimeborgia@protonmail.com wrote:
>>
>> > > > Would be good to allow arguments to be freely combined.
>> > > > But how does one loop over lists of these arguments from the
>> > > > code you posted?
>> > >
>> > > Something like this, for example:
>> > >
>> > > (dolist (f '(+ - list))
>> > > (dolist (a '(1 2 3))
>> > > (funcall f a)))
>> > >
>> > > > I could have the following, but got some difficulties about
>> > > > how to execute each command with its arguments, in the way you
>> > > > suggest.
>> > > >
>> > > > (defun fpln-test (symbol-list)
>> > > > (let ( (lookup-alist '((ar ((alkotr-ar arg-this)
>> > > > (alkotr-af arg-that arg-other)))
>> > > > (go ((alkotr-go arg-dim)
>> > > > (alkotr-gc arg-dum arg-sum))) )) )
>> > > >
>> > > > (dolist (actm symbol-list)
>> > > > (let ((commands (cdr (assoc actm lookup-alist))))
>> > > > (while commands
>> > > > (dolist (cmd commands)
>> > > > (apply (car cmd) (cdr cmd)))
>> > > > (message "Key '%s' not found in lookup-alist" key))))))
>> > >
>> > > When I wrote "using a list of function calls as the value of each alist
>> > > element seems reasonable" I was assuming you wanted them in lambda
>> > > expressions, where they are evaluated, as in the example you gave
>> > > previously. You can't use a function call as the first argument of
>> > > `apply' or` funcall' because a function call (which is just a list whose
>> > > first element is a function) is not a function.
>> >
>> > Have been trying to handle your suggestion not to use a lambda, but to
>> > handle the general case of executing a sequence of commands in a list,
>> > each element being a command to run.
>>
>>
>> Then you might try looping over lists of functions and arguments like in
>> the above schematic example I gave, though depending upon how you want
>> to combine the functions and arguments (e.g. if the functions don't all
>> have the same arity), this could become complicated. But without
>> specific examples of what you want to do I can't give more specific
>> advice.
>
> I have a sequence of commands for setting up a library component
>
> For instance
>
> ;; For option 'armg
> (add-to-list 'load-path (marnap-sec-fpln-waypt "NAPLN"))
> (require 'napyon)
>
> and
>
> ;; For option 'go
> (napyon 'go)
>
> Using lambda seems to offer more flexibility and maintainability, and
> extensibility.  Perhaps contrary to your original point of view?

Well, these examples suggest that you indeed want different arguments
for each function, and moreover have groups of function calls, so yes,
lambda forms work well for those, and they are probably simpler for such
cases than looping over lists of functions and arguments.

Steve Berman