I am sure this has been asked and formulated somewhere else. I don't know what the name of it is.
Let G be a set of groups. Given a list `l =: l_1 ... l_2` and a property `p` such that `p l_i` is in G, I would like a function `f` which partitions `l` into the successive maximally contiguous runs `r_1 ... r_k` such that for each `i`, `r_i` is a substring of `l`, there exists one `g` in G such that all `p r_ij = g` and the concatenation of `r_1 ... r_k` is equal to the original `l`. Examples: l = _1 _2 0 1 2 _1 4 5 _6` p = <&0 f l = _1 _2 ; 0 1 2 ; _1 ; 4 5 ; _6 ;. gets close, but one would need to specify where groups end possibly by comparing successive pairs of applications of `p`. Those positions would somehow need to be indicated as frets. /. gets close, but concatenates separate runs within the same group. Is this trivial, or should I write my own code for this? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
