PositionalFields constructor
Implementation
PositionalFields(Iterable<String> fields) {
var list = fields.toList();
_fields = UnmodifiableSetView<String>(list.toSet());
if (list.length != _fields.length) {
throw ArgumentError("fields not uniques: $fields");
}
_fieldsOrder = List<String>.unmodifiable(list);
for (var i = 0; i < list.length; ++i) {
var f = list[i];
_fieldsIndexes[f] = i;
}
}