split method
Splits text; whitespace-only input gives no chunks.
Implementation
List<TextChunk> split(String text) {
final n = text.length;
final chunks = <TextChunk>[];
var start = _skipSpace(text, 0);
while (start < n) {
final end = start + chunkSize >= n ? n : _cut(text, start);
var e = end;
while (e > start && _isSpace(text.codeUnitAt(e - 1))) {
e--;
}
if (e > start) {
chunks.add(
TextChunk(chunks.length, text.substring(start, e), start, e),
);
}
if (end >= n) break;
var next = end - overlap;
next = next <= start ? end : _wordStart(text, next, end);
start = _skipSpace(text, next);
}
return chunks;
}