diff options
Diffstat (limited to 'src/randoms.erl')
| -rw-r--r-- | src/randoms.erl | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/src/randoms.erl b/src/randoms.erl index a64012ca3..101241a3c 100644 --- a/src/randoms.erl +++ b/src/randoms.erl @@ -28,7 +28,7 @@ -author('alexey@process-one.net'). -export([get_string/0, uniform/0, uniform/1, uniform/2, bytes/1, - round_robin/1]). + round_robin/1, get_alphanum_string/1]). -define(THRESHOLD, 16#10000000000000000). @@ -71,3 +71,21 @@ bytes(N) -> -spec round_robin(pos_integer()) -> non_neg_integer(). round_robin(N) -> p1_time_compat:unique_integer([monotonic, positive]) rem N. + +-spec get_alphanum_string(non_neg_integer()) -> binary(). +get_alphanum_string(Length) -> + list_to_binary(get_alphanum_string([], Length)). + +-spec get_alphanum_string(string(), non_neg_integer()) -> string(). +get_alphanum_string(S, 0) -> S; +get_alphanum_string(S, N) -> + get_alphanum_string([make_rand_char() | S], N - 1). + +-spec make_rand_char() -> char(). +make_rand_char() -> + map_int_to_char(uniform(0, 61)). + +-spec map_int_to_char(0..61) -> char(). +map_int_to_char(N) when N =< 9 -> N + 48; % Digit. +map_int_to_char(N) when N =< 35 -> N + 55; % Upper-case character. +map_int_to_char(N) when N =< 61 -> N + 61. % Lower-case character. |