Re: Making alist that executes multiple commands

[Stephen Berman]

On Mon, 25 Nov 2024 21:37:12 +0000 Heime <heimeborgia@protonmail.com> wrote:

> Sent with Proton Mail secure email.
>
> On Tuesday, November 26th, 2024 at 9:27 AM, Stephen Berman
> <stephen.berman@gmx.net> wrote:
>
>> 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
>
> For what reasons have you suggested looping over lists of functions and
> arguments?  Would that have a list of function names, and a list with
> their arguments?
>
> You mentioned some advantages for working with arguments, but do not
> understand precisely what arguments to what were you referring to.

I mentioned freely combining functions and arguments and gave a
schematic example with nested dolist's; I haven't given it more thought
than that.

> With the lamdba version, I am getting the whole thing to work as intended.

Then be happy and continue to use it!

Steve Berman