Re: A better way to access records.

[Brendan Tildesley <mail@brendan.scot>]

On 1/11/20 8:01 am, Ludovic Courtès wrote:
> Hi,
>
> Brendan Tildesley <mail@brendan.scot> skribis:
>
>> In the guix codebase, on many occasions there appear things like this:
>>
>> (match-lambda
>>      (($ <agetty-configuration> agetty tty term baud-rate auto-login
>>          login-program login-pause? eight-bits? no-reset? remote?
>> flow-control?
>>          host no-issue? init-string no-clear? local-line extract-baud?
>>          skip-login? no-newline? login-options chroot hangup?
>> keep-baud? timeout
>>          detect-case? wait-cr? no-hints? no-hostname? long-hostname?
>>          erase-characters kill-characters chdir delay nice extra-options)
>>       (list
>>        ....
> This has officially been Bad Practice for a while.  Instead, the
> recommended approach is to use ‘match-record’ from (guix records).
> There are examples of that primarily in (gnu services …).
>
> Does that help?
>
> Thanks,
> Ludo’.

I suppose It makes sense that one would want to be explicit about names 
in a source code file.

BTW, if that is the recommended way, would someone with an understanding 
of the records.scm code mind adding support for delayed & thunked fields 
in match-record? There is a TODO there. I wouldn't know how to do it.