Sourceval make : ?init:t->?window_log_max:int ->unit ->t
make () are the given compression parameters. Those unspecfied take the value of init which defaults to default. See corresponding accessors for the default values.
window_log_max is the maximum back-reference distance in power of two allowed for decoding. Errors if the stream requires more. 0 is the default maximum window. This can be used to limit the memory used for decoding.