ListFormatGenerator typedef
Signature used by ListFormat to construct the key path for a single element in a list during encoding.
Parameters:
prefix: The current container key (e.g."foo"). This is always provided by the encoder.key: Optional element key. For ListFormat.indices it is the element index as a string ("0","1", …). Other formats ignore it.
Returns the key path string to be written for that element (without the
'=' or the value), e.g. "foo[0]", "foo[]", or "foo".
Implementation
typedef ListFormatGenerator = String Function(String prefix, [String? key]);