splitMapJoin method Null safety

String splitMapJoin(
  1. Pattern pattern,
  2. {String onMatch(
    1. Match
  3. String onNonMatch(
    1. String

Splits the string, converts its parts, and combines them into a new string.

The pattern is used to split the string into parts and separating matches. Each match of Pattern.allMatches of pattern on this string is used as a match, and the substrings between the end of one match (or the start of the string) and the start of the next match (or the end of the string) is treated as a non-matched part. (There is no omission of leading or trailing empty matchs, like in split, all matches and parts between the are included.)

Each match is converted to a string by calling onMatch. If onMatch is omitted, the matched substring is used.

Each non-matched part is converted to a string by a call to onNonMatch. If onNonMatch is omitted, the non-matching substring itself is used.

Then all the converted parts are concatenated into the resulting string.

'Eats shoots leaves'.splitMapJoin((RegExp(r'shoots')),
    onMatch:    (m) => '${m[0]}',  // (or no onMatch at all)
    onNonMatch: (n) => '*'); // Result: "*shoots*"


String splitMapJoin(Pattern pattern,
    {String Function(Match)? onMatch, String Function(String)? onNonMatch});