On 2020/02/06 14:29:55, Dan Eble wrote: > The reviewers are turning the first question I asked around and asking it back > to me. I don't know if this is useful without other stuff I've been working on. > That's why I've posted it for review. I thought that you (well, mainly I > thought that David K.) might know of some corner of LilyPond where delaying a > \set (or similar thing) until the end of the current time step would be useful.
I remember very faintly (incorrectly???) that many years ago I had a problem of doing something at the last point in time, as points of time could be deduced only from the beginning of durations, not from the end of those; if that is so (or if there are cases when determining a point of time is more natural as the end of a duration than as the beginning of another one), \post is definitely useful. Another conceivable meaning is, used together with \once: "tweak something, and when it finished, tweak something else" (may perhaps be useful when pasting music from tiny fragments or using a complex hierarchy of music functions). This meaning would perhaps be - expressed better with \next (or \then? is it reserved?) than \post; - supported better if \once and \post could be iterated like if .. else if .. else, i.e. if \once \set <tweak1> \post \once \set <tweak2> \post \set <tweak3> <note1> <note2> ... meant \set <tweak1> <note1> \set <tweak2> <note2> \set <tweak3> ... but as the new set-once-post.ly regtest shows, this is not how it works with this patch. https://codereview.appspot.com/581600043/