fromPgn static method
Parse the PGN for any comment or return null.
Implementation
static PgnCommentShape? fromPgn(String str) {
final color = CommentShapeColor.parseShapeColor(str.substring(0, 1));
final from = Square.parse(str.substring(1, 3));
if (color == null || from == null) return null;
if (str.length == 3) {
return PgnCommentShape(color: color, from: from, to: from);
}
final to = Square.parse(str.substring(3, 5));
if (str.length == 5 && to != null) {
return PgnCommentShape(color: color, from: from, to: to);
}
return null;
}