Creating arbitrary/isolated RepeatSlash objects

[Galen Hazelwood]

Hello all.

I have another question, this time about percent repeats. I'm repeating a long, complex keyboard figure which extends across both staves, and using a combination of MagnifyMusic reduction and percent repeats to keep things manageable. The only thing is that the repeat slashes only appear on one staff; I'd like to mirror them in the other, just so things look symmetric.

There's a function in the documentation for generating arbitrary percent figures in the score...

makePercent =
#(define-music-function (note) (ly:music?)
   "Make a percent repeat the same length as NOTE."
   (make-music 'PercentEvent
               'length (ly:music-length note)))

...so I assumed I could just substitute a RepeatSlashEvent for the Percent Event. Turns out I can't; it compiles fine, but throws an error when I try to use it. 

ERROR: Wrong type (expecting exact integer): ()

I could just shove the repeat slashes into the middle between the staves, but I'd rather have them mirrored if I could. Is there some way to make a function like this that works, or is there a completely different path that makes more sense?

Thanks,

--Galen

example-repeat.ly
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example-repeat.pdf
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