Editorial parentheses for a series of staccati

[Jun Tamura]

Hello,

I want to achieve something like in the attached example. For the Viola part in 
the example, editorial addition of a series of staccati is indicated with the 
left bracket on the first staccato dot and the right bracket on the last 
staccato dot. I’d like to have a left parenthesis on the first staccato dot of 
a series of staccati and a right parenthesis on the last staccato dot. I guess 
this can be achieved if I can define functions like
\parenthesizeLeft
and
\parenthesizeRight
but I don’t have enough knowledge about Scheme.

Thanks in advance for your help, and best regards.

Jun