Generates a password with length Len.

Calling generate(10) is the same as calling

generate(10, [upper, lower, number, symbol]).

See also: generate/2.

-spec generate(Len, OpsList) -> Password | {error, Reason}
                  when Len :: integer(), OpsList :: list(), Password :: list(), Reason :: term().

Generates a password with length Len and options OpsList

generate/2 takes the length of password and a list of options. OpsList must contain the atoms upper, lower, number, symbol and/or tuples on the format {upper, 2}, representing one of the atoms above and the maximum number of occurrences.