Here are another couple abstractions from a night of building things that needed them:
YALA (yet-another-list-abstraction): [list-split-at], which splits a list into multiple lists each time it encounters a delimiter, so [a b c . d e f . g h i j( into [list-split-at .] will spit out 3 lists, [a b c(, [d e f( and [g h i j(. Requires list-abs, but is pure-pd. (and Frank as always if you like it you are welcome to take it for list-abs).
and
[beat2frac], which takes a note division like [1/16( and outputs the fraction of a quarter note as a float (so, that would give 0.25). A bit odd, but it makes it very convenient to multiply by the length of one beat in seconds (60 / BPM) and get the input beat length in seconds. It also supports triplets (e.g. [1/16T( or [1/16t(, would give 0.1666), and arbitrary divisions like [3/17( (gives 0.705822). Requires list-split-at, list-abs and zexy.
Cheers Luke