Let me suggest to the masters in the list the possibility to add a new
opcode.
It should work like deltapi (that it, inside a delayr/delayw pair) but
*injecting* and audio signal inside the delay line, and not extracting
it.
This simple hack would allow a great simplification of multiple
feedbacked delay lines (Gardner reverbs are an example, also piecewiese
waveguide instruments with tone holes and so on...), which till now must
be modelled with multiple delayr/delayw pairs. They would only need a
single pair and as much deltapi/tapw pairs as needed inside it.
It should work like delayw, something like

tapw asig, ktime, imode

asig - Signal to be injected into the delay line. Uses linear
interpolation.
ktime - Time in seconds
imode - = 0 (default) mix with the current value in the delay  =! 0
replace existing value. Or viceversa maybe...

What do you think? I´ve never attempted to add a new opcode, it might
well be easy, but I´ve never tried it. I´d really like something like
this, it seems logical and useful.

Josep M Comajuncosas