SQlite only -- snippet to demonstrate how to SPLIT STRING in substrings separated with custom separators.

sqlite_string_split.sql

with separators as ( values (' '), (','), ('-'), ('.') ),
  source (s) as ( select " Will, thought and action." ),
  bag (q) as ( -- POSITIONS OF ALL SEPARATORS
    with dim (len) as ( select length(s) from source ),
    ndx (n) as (
      select 1 union all select n+1 from ndx, dim where n < len
    ) select 0 --> PSEUDO SEPARATOR IN FRONT OF SOURCE STRING
      union all select n from ndx, source where substr(s, n, 1) in separators
      union all select len+1 from dim --> PSEUDO SEPARATOR AT BOTTOM
  ),
  pre (p) as ( -- POSITIONS OF SEPARATORS PRECEDING NON SEPARATORS
    select q from bag where not q+1 in bag
  ) select printf("%2d %2d <%s>", p, z, substr(s, p+1, z-p-1)) from (
      select p, (select min(q) from bag where q > p) as z from pre where z
    ), source;