Splits a string into a list of substrings, breaking at occurrences of a
specified character.
DESCRIBE
words2 char s splits the string s into a list of substrings. Splitting
occurs at each occurrence of a sequence of the character char. The char
characters do not appear in the list of substrings. Leading and trailing
occurrences of char are also thrown away. If char is not a
single-character string (its length is not 1), then s will not be split and
so the result will be the list [s].
FAILURE
Never fails.
EXAMPLE
#words2 `/` `/the/cat//sat/on//the/mat/`;;
[`the`; `cat`; `sat`; `on`; `the`; `mat`] : string list
#words2 `//` `/the/cat//sat/on//the/mat/`;;
[`/the/cat//sat/on//the/mat/`] : string list