Function: strsplit
Section: programming/specific
C-Name: strsplit
Prototype: GDG
Help: strsplit(s,{p = ""}): splits the string s into a vector of strings, with
 p acting as a delimiter between successive fields; if p is empty or omitted,
 split into characters.
Doc: splits the string $s$ into a vector of strings, with $p$ acting as a
 delimiter. If $p$ is empty or omitted, split the string into characters.
 \bprog
 ? strsplit("abc::def::ghi", "::")
 %1 = ["abc", "def", "ghi"]
 ? strsplit("abc", "")
 %2 = ["a", "b", "c"]
 ? strsplit("aba", "a")
 @eprog\noindent If $s$ starts (resp.~ends) with the pattern $p$, then the
 first (resp.~last) entry in the vector is the empty string:
 \bprog
 ? strsplit("aba", "a")
 %3 = ["", "b", ""]
 @eprog
