desired features

[fulvio ciriaco]

Recently I was thinking about how music typesetting could be written
in lout.
Seemed to me that it would be not so difficult if two features where
not missing:

In
{a  |1c b} |0co c
c overstrikes on b.
Could | and / operators be extended so that  c be put between a and b, i.e. with reference to the principal mark, and without deleting the b mark?
example: {a  |1co b} |0.5co c  ----->  a  | 0.5co c |0.5co b
I was not able to emulate this anyway with the available operators.

Curiosity: the following sequence
@HContract{{} | b} |0co {x}
seems equivalent to {b} @Overstrike {x}.

a  |1c b | 1c c /
a  | @StartHSpan ...... | @HSpan
works fine but the operators @StartHSpan, @StartVSpan are allowed to exist only in an horizontal list.

I would like to be able to do the following

{a /1c b /1c c} | {a / @startvspan / .... / @vspan}

I presume such operators should be restricted to unbreakable objects, and perhaps they seemed useless for text typesetting. However they complete the horizontal/vertical symmetry.

Best regards and thanks for your fine work

-- 
Fulvio Ciriaco.