Re: Language selection code

[David Nalesnik]

Hi Simon,


On Thu, Mar 26, 2015 at 6:43 PM, Simon Albrecht <address@hidden>
wrote:

[...]


> So the roadmap would include
> – discussing design and coding (?)
>

I haven't gone through this thoroughly, but I did notice that an invalid
statement like this
\language general.deutsch.foo
isn't gracefully dealt with.

I haven't studied this enough to diagnose the problem, but I did notice the
following:

% extended from music-functions-init.ly:603
language =
#(define-void-function
  (parser location arg)
  ;; Usage:
  ;; \language input.LANG or
  ;; \language output.LANG or
  ;; \language LANG—which is equivalent to
  ;; \language general.LANG or to the first two combined
  (symbol-list-or-symbol?)
  (_i "Define languages for input (i.e. set note names for @var{language}),
output (i.e. display tagline and table of contents in @var{language}), or
both.")


  (let* ((correct-input (if (> (length arg) 2) #f #t))
         (channel (if (= 2 (length arg)) ;if a channel is given,
                      (car arg)          ;use it
                      'general))         ;else apply to both
         (language (cond ((= 1 (length arg)) (list-ref arg 0))
                     ((= 2 (length arg)) (list-ref arg 1))))


If correct-input is #f, language will be undefined.  You could add
(else #f)


         (input-lang (if language ;if input isn’t wrong
                         language
                         'nederlands)) ;default


The boolean value of #<unspecified> is ... #t, so input-lang will select
language if the input is not correct.  language will be #<unspecified>.

         (output-lang (if language
                          language
                          'english)))

As above.

Possibly you shouldn't bind the variables after correct-input unless the
input is correct.

HTH,
David

P.S.  Thanks for working on this!