Let repeatTie work inside of event-chord

Let repeatTie work inside of event-chord

The previous coding of repeat-tie-engraver.cc is replaced by the
renamed coding of the laissez-vibrer-engraver.

[thomasmorley651, 2017-10-21 16:24:37]

please review

[benko.pal, 2017-10-22 19:26:12]

if it's really the same, can't it be used without copying?  or if separate
classes are absolutely needed, can't the common part be gathered in a common
base class?

[dak, 2017-10-22 20:01:03]

On 2017/10/22 19:26:12, benko.pal wrote:
> if it's really the same, can't it be used without copying?  or if separate
> classes are absolutely needed, can't the common part be gathered in a common
> base class?

You mean, like with Slur/PhrasingSlur?  Well, for one thing, then someone needs
to take over from Thomas Morley: he does not actually know C++.  For another,
figuring out the current problem (something does not like parenthesizing) is
still necessary.

[thomasmorley651, 2017-10-22 20:09:13]

On 2017/10/22 20:01:03, dak wrote:
> On 2017/10/22 19:26:12, benko.pal wrote:
> > if it's really the same, can't it be used without copying?  or if separate
> > classes are absolutely needed, can't the common part be gathered in a common
> > base class?
> 
> You mean, like with Slur/PhrasingSlur?  Well, for one thing, then someone
needs
> to take over from Thomas Morley: he does not actually know C++.  

The idea is pretty nice, though I really don't know enough C++ ...
And I've absolutely no problem to pass the torch to someone else :)

> For another,
> figuring out the current problem (something does not like parenthesizing) is
> still necessary.

I just posted some thoughts on the tracker.

[thomasmorley651, 2017-10-24 08:31:11]

reflecting discussion

[thomasmorley651, 2017-10-24 08:34:13]

I tried to make both engravers as equal as I could, to make it easy for a follow
up to create a common base class for both.
My own naive attempts to introduce something like 'semi-tie-event' failed,
though.

[dak, 2017-10-24 10:06:49]

On 2017/10/24 08:34:13, thomasmorley651 wrote:
> I tried to make both engravers as equal as I could, to make it easy for a
follow
> up to create a common base class for both.
> My own naive attempts to introduce something like 'semi-tie-event' failed,
> though.

This looks really similar.  I worked off the current definition of
Laissez_vibrer_engraver and created a derived Repeat_tie_engraver in a separate
issue:

Tracker issue: 5220 (https://sourceforge.net/p/testlilyissues/issues/5220/)
Rietveld issue: 332990043 (https://codereview.appspot.com/332990043)
Issue description:
  Issue 5220/3: Derive Repeat_tie_engraver from
  Laissez_vibrer_engraver   Issue 5220/2: Virtualize some parts of
  Laissez_vibrer_engraver  This is in preparation of using it for
  Repeat_Tie_engraver  Issue 5220/1: Create laissez-vibrer-engraver.hh
  Still missing regtest/doc.

If you want to replace the lv_column_ and similar elements with semi_tie_column_
for better generality/readability, make this a followup patch.