Re: Allow Scheme functions to be called inside of markup (issue 285070043 by address@hidden)

[thomasmorley65]

On 2016/01/16 20:37:23, dak wrote:
> On 2016/01/16 19:54:54, thomasmorley651 wrote:
> > After some testings I'm quite happy with it, apart from one use
case:
> >
> > fooII =
> > #(define-scheme-function (arg)(markup-list?)
> > #{
> >   \markup \column $arg
> > #})
> >
> > %% doesn't work:
> > \markup \line { "xy" \fooII { "does" "not" "work"} }
> > %% works
> > \markup \line { "xy" \fooII \markuplist { "whatever" "else" } }
> > \markup \line { "xy" \fooII #'("whatever" "else") }
> >
> > I think I know why the first case doesn't work. Though, I have no
good idea
> how
> > to explain it in the docs without telling a very technical story,
likely very
> > confusing to the average-user.
> > Additionally, having to add \markuplist as in the second example is
not nice.
> > Only a little better is the need to revert to scheme as done in the
third
> > example.
> >
> > What other problematic cases can you predict deductively?

> Sigh.  This looks like a can of worms.

> Arguments of type markup?/markup-list? will obviously be problematic
(apart from
> the trivial case of strings) without explicit \markup/\markuplist.  I
am afraid
> that one would need to teach markup-mode internal arguments to generic
function
> argument lists.  That would appear to be a likely user expectation.

Agreed. Users would be surprised to find the following not working:

fooVI = #(define-scheme-function (arg)(markup?) arg)
\markup \line { "xy" \fooVI \with-color #red "bla" }


> However, `{' and `}' are mode-independent, and so { } already stands
for an
> empty sequential music expression and making it stand at the same time
for an
> empty markup list...  Ugh.

> So much for the triviality of the change.

Well, it would be some syntactic sugar. No real need for it.
Bury it?


https://codereview.appspot.com/285070043/