moveBackUntil method Null safety

bool moveBackUntil(
  1. Characters target
)

Moves to the range after the previous occurence of target.

If there is an occurrence of target in the characters preceding the current range, then the new range contains the characters after the last such occurrence, and up to the start of the current range.

If there is no occurrence of target after the current range, the new range contains all the characters preceding the current range, from the start of the string to the start of the current range.

Returns true if there was an occurrence of target.

Implementation

bool moveBackUntil(Characters target);