Re: Error in tweak parameter doesn't generate error message

[Neil Puttock]

2009/4/23 Nick Payne <address@hidden>:
> I was trying to move a TextSpanner with \tweak and couldn't figure out why
> it wouldn't move. I eventually noticed that I had accidentally typed
>
> -\tweak #'extra-ofset
>
> instead of
>
> -\tweak #'extra-offset
>
> but this did not generate any warning. Looks like this is a general thing
> with \tweak, as I tried changing \tweak #'color to \tweak #'colon and got no
> warning there either.

There may be a good reason why there's no type-checking for \tweak,
but you can redefine it if you like:

tweak =
#(define-music-function (parser location sym val arg)
   (symbol? scheme? ly:music?)
   (_i "Add @code{sym . val} to the @code{tweaks} property of @var{arg}.")
   (if (equal? (object-property sym 'backend-type?) #f)
       (ly:warning "cannot find property type-check for: ~a" sym)
       (set!
        (ly:music-property arg 'tweaks)
        (acons sym val
               (ly:music-property arg 'tweaks))))
   arg)

Regards,
Neil