Re: Doc: simplify example for unpure-pure containers (issue 5623044)

[dak]

On 2012/02/03 15:38:16, Pavel Roskin wrote:
> To be honest, there are many things I don't understand.  In fact, I
reduced the
> example to understand it better.

> Why is horizontal spacing affected even though the purity affects the
Y-axis
> only?  Why do stems fix the spacing?  Why doesn't this cause the
spacing
> problem:

>    \override NoteHead #'text = \markup { "o" }
>    \override NoteHead #'stencil = #ly:text-interface::print

> But this does cause the problem:

>    \override NoteHead #'text = \markup { "o" }
>    \override NoteHead #'stencil =
>     #(lambda (grob) (ly:text-interface::print grob))

> Cannot it happen a simple change would make Lilypond recognize lambda
> expressions as pure functions, breaking this example?  Maybe I removed
some
> future-proofing?

> Perhaps some answers to those questions could be used to improve the
> documentation.

See the end of define-grobs.scm.  purity detection is hardwired.

http://codereview.appspot.com/5623044/