Defining an array in a let clause.

Defining an array in a let clause.

[Heime]

How can I set up an array of five elements in a let clause.

  (let ( (ss (nth 0 (decode-time)))    ; seconds
         (mm (nth 1 (decode-time)))    ; minutes
         (hh (nth 2 (decode-time)))    ; hours
         (us (nth 2 (current-time)))   ; microsecond
         (ps (nth 3 (current-time)))   ; picosecond
         (lc (make-array '(5))) )

Re: Defining an array in a let clause.

[Eli Zaretskii]

> Date: Mon, 05 Dec 2022 11:40:44 +0000
> From: Heime <heimeborgia@protonmail.com>
> 
> 
> How can I set up an array of five elements in a let clause.
> 
>   (let ( (ss (nth 0 (decode-time)))    ; seconds
>          (mm (nth 1 (decode-time)))    ; minutes
>          (hh (nth 2 (decode-time)))    ; hours
>          (us (nth 2 (current-time)))   ; microsecond
>          (ps (nth 3 (current-time)))   ; picosecond
>          (lc (make-array '(5))) )

There are no arrays in Emacs.  Do you mean vector? if so use the function
'vector' to construct a vector.  If, OTOH, you want a list, use the function
'list' instead.

Re: Defining an array in a let clause.

[Heime]

------- Original Message -------
On Monday, December 5th, 2022 at 12:54 PM, Eli Zaretskii <eliz@gnu.org> wrote:


> > Date: Mon, 05 Dec 2022 11:40:44 +0000
> > From: Heime heimeborgia@protonmail.com
> > 
> > How can I set up an array of five elements in a let clause.
> > 
> > (let ( (ss (nth 0 (decode-time))) ; seconds
> > (mm (nth 1 (decode-time))) ; minutes
> > (hh (nth 2 (decode-time))) ; hours
> > (us (nth 2 (current-time))) ; microsecond
> > (ps (nth 3 (current-time))) ; picosecond
> > (lc (make-array '(5))) )
> 
> 
> There are no arrays in Emacs. Do you mean vector? if so use the function
> 'vector' to construct a vector. If, OTOH, you want a list, use the function
> 'list' instead.

Correct, a vector with five elements.

Re: Defining an array in a let clause.

[Eli Zaretskii]

> Date: Mon, 05 Dec 2022 13:56:53 +0000
> From: Heime <heimeborgia@protonmail.com>
> Cc: help-gnu-emacs@gnu.org
> 
> ------- Original Message -------
> On Monday, December 5th, 2022 at 12:54 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> 
> > > Date: Mon, 05 Dec 2022 11:40:44 +0000
> > > From: Heime heimeborgia@protonmail.com
> > > 
> > > How can I set up an array of five elements in a let clause.
> > > 
> > > (let ( (ss (nth 0 (decode-time))) ; seconds
> > > (mm (nth 1 (decode-time))) ; minutes
> > > (hh (nth 2 (decode-time))) ; hours
> > > (us (nth 2 (current-time))) ; microsecond
> > > (ps (nth 3 (current-time))) ; picosecond
> > > (lc (make-array '(5))) )
> > 
> > 
> > There are no arrays in Emacs. Do you mean vector? if so use the function
> > 'vector' to construct a vector. If, OTOH, you want a list, use the function
> > 'list' instead.
> 
> Correct, a vector with five elements.

Then the function 'vector' is what you need to use here.

Re: Defining an array in a let clause.

[Eduardo Ochs]

On Mon, 5 Dec 2022 at 11:44, Eli Zaretskii <eliz@gnu.org> wrote:
>
> > Date: Mon, 05 Dec 2022 13:56:53 +0000
> > From: Heime <heimeborgia@protonmail.com>
> > Cc: help-gnu-emacs@gnu.org
> >
> > ------- Original Message -------
> > On Monday, December 5th, 2022 at 12:54 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> >
> >
> > > > Date: Mon, 05 Dec 2022 11:40:44 +0000
> > > > From: Heime heimeborgia@protonmail.com
> > > >
> > > > How can I set up an array of five elements in a let clause.
> > > >
> > > > (let ( (ss (nth 0 (decode-time))) ; seconds
> > > > (mm (nth 1 (decode-time))) ; minutes
> > > > (hh (nth 2 (decode-time))) ; hours
> > > > (us (nth 2 (current-time))) ; microsecond
> > > > (ps (nth 3 (current-time))) ; picosecond
> > > > (lc (make-array '(5))) )
> > >
> > >
> > > There are no arrays in Emacs. Do you mean vector? if so use the function
> > > 'vector' to construct a vector. If, OTOH, you want a list, use the function
> > > 'list' instead.
> >
> > Correct, a vector with five elements.
>
> Then the function 'vector' is what you need to use here.

Try this:

  (cl-destructuring-bind (ss mm hh &rest rest) (decode-time)
    (cl-destructuring-bind (_ _ us ps &rest rest) (current-time)
      (vector ss mm hh us ps)))

I don't know cl-lib well... I guess that there are better ways to
do that, and I hope that other people would come up and show
what are these better ways... =)
  Cheers,
    Edrx
    http://angg.twu.net/eepitch.html

Re: Defining an array in a let clause.

[Jean Louis]

* Heime <heimeborgia@protonmail.com> [2022-12-05 14:42]:
> 
> How can I set up an array of five elements in a let clause.
> 
>   (let ( (ss (nth 0 (decode-time)))    ; seconds
>          (mm (nth 1 (decode-time)))    ; minutes
>          (hh (nth 2 (decode-time)))    ; hours
>          (us (nth 2 (current-time)))   ; microsecond
>          (ps (nth 3 (current-time)))   ; picosecond
>          (lc (make-array '(5))) )

For array references, evaluate below functions:

(info "(elisp) Array Functions")

(info "(elisp) Sequences Arrays Vectors")

-- 
Jean

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

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https://stallmansupport.org/

Re: Defining an array in a let clause.

[Heime]

------- Original Message -------
On Monday, December 5th, 2022 at 7:42 PM, Jean Louis <bugs@gnu.support> wrote:


> * Heime heimeborgia@protonmail.com [2022-12-05 14:42]:
> 
> > How can I set up an array of five elements in a let clause.
> > 
> > (let ( (ss (nth 0 (decode-time))) ; seconds
> > (mm (nth 1 (decode-time))) ; minutes
> > (hh (nth 2 (decode-time))) ; hours
> > (us (nth 2 (current-time))) ; microsecond
> > (ps (nth 3 (current-time))) ; picosecond
> > (lc (make-array '(5))) )
> 
> 
> For array references, evaluate below functions:
> 
> (info "(elisp) Array Functions")
> 
> (info "(elisp) Sequences Arrays Vectors")

A vector solved it with (lc (make-vector 6 0))

Re: Defining an array in a let clause.

[Stefan Monnier via Users list for the GNU Emacs text editor]

>          (mm (nth 1 (decode-time)))    ; minutes
>          (hh (nth 2 (decode-time)))    ; hours

This may end up telling it's 14:59 whereas it's actually 14:00 (because
you were unlucky enough to call the first `decode-time` when it's still
13:59 and the second when we're now 14:00.

Rule of thumb: don't call twice a function unless there's a good reason
for it.  Instead store the result of the first call in a var and then
refer to that var.


        Stefan