Re: How to convert a char to a property

[Pascal J. Bourguignon]

Cecil Westerhof <Cecil@decebal.nl> writes:

> Op dinsdag 27 jul 2010 10:29 CEST schreef Cecil Westerhof:
>
>> I have the following property list:
>> (defvar dcbl-bbdb-user-defined-fields (list :L "mail-alias"
>> :M "mailer"
>> :P "playlist"
>> :s "subjects"
>> :t "type"
>> :w "website")
>> "User defined fields in the bbdb with parameter to insert into buffer")
>>
>> With (getf dcbl-bbdb-user-defined-fields :M) I get "mailer".
>>
>> But I want to work parameter driven. So for example I have:
>> (setq parameters "MLst")
>> (setq current-char (string-to-char parameters))
>>
>> The variable current-char now contains 77. How could I use
>> current-char to retrieve "mailer"?
>
> At the moment I use another solution.
>
> I now have:
>     (defvar dcbl-bbdb-user-defined-fields '(("L" "mail-alias")
>                                             ("M" "mailer")
>                                             ("P" "playlist")
>                                             ("s" "subjects")
>                                             ("t" "type")
>                                             ("w" "website"))
>       "User defined fields in the bbdb with parameter to insert into buffer")
>
> and use the following code:
>     (setq field-name     nil
>           parameters     dcbl-bbdb-user-defined-fields
>           this-value     nil)
>     (while parameters
>       (setq this-parameter (car parameters)
>             parameters     (cdr parameters))
>       (when (string= current-char (car this-parameter))
>         (setq field-name (car (cdr this-parameter))
>               parameters nil)))
>
> The variable current-char is the parameter (as a string) that I am
> searching for.
>
> This does work, but I do not know if it is very efficient. Is this a
> good solution, or should I code it differently?

If you have characters and want to map them, why do you make a table
mapping keywords or strings?  Make a table mapping characters!


     (defvar dcbl-bbdb-user-defined-fields '((?L . "mail-alias")
                                             (?M . "mailer")
                                             (?P . "playlist")
                                             (?s . "subjects")
                                             (?t . "type")
                                             (?w . "website"))
       "An a-list of User defined fields in the bbdb with parameter to insert 
into buffer")

    (defun get-field-name-from-character (ch)
       (cdr (assoc ch dcbl-bbdb-user-defined-fields)))



-- 
__Pascal Bourguignon__                     http://www.informatimago.com/