If clause depending on name of the day

If clause depending on name of the day

[Sven Bretfeld]

Hi all

Is it possible to have an if-condition that looks for the current day?
So that the then-expression does something different on Tuesday than on
Friday? 

This is not working:

 (if (string-equal 'current-time-string ".*Tue.*")
    (delete-other-windows)
  (split-window-horizontally))

Thanks for help

Sven

p.s. unnecessary to mention that I have only a weak knowledge of elisp.

Re: If clause depending on name of the day

[Lars Ljung]

"Sven Bretfeld" <sven.bretfeld@gmx.ch> writes:
> Is it possible to have an if-condition that looks for the current day?
> So that the then-expression does something different on Tuesday than on
> Friday? 

(nth 6 (decode-time)) returns 0-6 for Sunday-Saturday.

-- 
Lars Ljung

Re: If clause depending on name of the day

[Pascal J. Bourguignon]

"Sven Bretfeld" <sven.bretfeld@gmx.ch> writes:

> Is it possible to have an if-condition that looks for the current day?
> So that the then-expression does something different on Tuesday than on
> Friday? 
>
> This is not working:
>
>  (if (string-equal 'current-time-string ".*Tue.*")
>     (delete-other-windows)
>   (split-window-horizontally))

What Lars said.
Otherwise  you would have wanted:

   (require 'cl)

   (search "Tue" (current-time-string)) ; search a substring

or:

   (string-match "Tue" (current-time-string)) ; search a regexp.


> p.s. unnecessary to mention that I have only a weak knowledge of elisp.

          An Introduction to Programming in Emacs Lisp
          http://www.gnu.org/software/emacs/emacs-lisp-intro/
          (for non-programmers)

          Emacs Lisp Manual
          http://www.gnu.org/software/emacs/manual/elisp.html

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.

RE: If clause depending on name of the day

[Drew Adams]

> > Is it possible to have an if-condition that looks for the 
> > current day?  So that the then-expression does something
> > different on Tuesday than on Friday? This is not working:
> >
> > (if (string-equal 'current-time-string ".*Tue.*")
         ^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^
> >    (delete-other-windows)
> >  (split-window-horizontally))
> 
> (nth 6 (decode-time)) returns 0-6 for Sunday-Saturday.

Plus, to address the code originally suggested:

1. `current-time-string' is a function that returns the time string when
invoked.  To invoke it you would use: (current-time-string), not
'current-time-string.

2. You are trying to match a regexp against a literal string, but you are using
the wrong function (`string-equal') to do it.  Use `string-match-p' for matching
(or `string-match' if that's not available).  (`string-equal' does literal
comparison.)

(But Lars's answer provides a better solution than formatting a time string and
then matching it.)

Re: If clause depending on name of the day

[PJ Weisberg]

On Tue, Apr 3, 2012 at 12:32 PM, Lars Ljung <lars@matholka.se> wrote:
> "Sven Bretfeld" <sven.bretfeld@gmx.ch> writes:
>> Is it possible to have an if-condition that looks for the current day?
>> So that the then-expression does something different on Tuesday than on
>> Friday?
>
> (nth 6 (decode-time)) returns 0-6 for Sunday-Saturday.

So you could do something like this:

(require 'cl)
(case (nth 6 (decode-time))
  (0
   (message "Today is Sunday"))
  ((1 3 5)
   (message "Today is Monday, Wednesday, or Friday"))
  (2
   (message "Today is Tuesday"))
  (t
   (message "It's some other day.")))

-PJ

Gehm's Corollary to Clark's Law: Any technology distinguishable from
magic is insufficiently advanced.

Re: If clause depending on name of the day

[Sven Bretfeld]

Dear all

"Pascal J. Bourguignon" <pjb@informatimago.com> writes:

> "Sven Bretfeld" <sven.bretfeld@gmx.ch> writes:
>
>> Is it possible to have an if-condition that looks for the current day?
>> So that the then-expression does something different on Tuesday than on
>> Friday? 
>>
>> This is not working:
>>
>>  (if (string-equal 'current-time-string ".*Tue.*")
>>     (delete-other-windows)
>>   (split-window-horizontally))
>
> What Lars said.
> Otherwise  you would have wanted:
>
>    (require 'cl)
>
>    (search "Tue" (current-time-string)) ; search a substring
>
> or:
>
>    (string-match "Tue" (current-time-string)) ; search a regexp.

This is working just as I wanted it to. Thank you very much. 

>> p.s. unnecessary to mention that I have only a weak knowledge of elisp.
>
>           An Introduction to Programming in Emacs Lisp
>           http://www.gnu.org/software/emacs/emacs-lisp-intro/
>           (for non-programmers)

Bookmarked for later reading. Thanks.

Sven

Re: If clause depending on name of the day

[Pascal J. Bourguignon]

PJ Weisberg <pj@irregularexpressions.net> writes:

> On Tue, Apr 3, 2012 at 12:32 PM, Lars Ljung <lars@matholka.se> wrote:
>> "Sven Bretfeld" <sven.bretfeld@gmx.ch> writes:
>>> Is it possible to have an if-condition that looks for the current day?
>>> So that the then-expression does something different on Tuesday than on
>>> Friday?
>>
>> (nth 6 (decode-time)) returns 0-6 for Sunday-Saturday.
>
> So you could do something like this:
>
> (require 'cl)
> (case (nth 6 (decode-time))
>   (0
>    (message "Today is Sunday"))
>   ((1 3 5)
>    (message "Today is Monday, Wednesday, or Friday"))
>   (2
>    (message "Today is Tuesday"))
>   (t
>    (message "It's some other day.")))

(message "Today is %s" (aref ["Sunday" "Monday" "Tuesday" "Wednesday"
                               "Thirsday" "Friday" "Saturday"]
                             (nth 6 (decode-time))))
--> "Today is Tuesday"

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.