rand

func Int ¶

func Int() int

func Int32 ¶

func Int32() int32

func Int64 ¶

func Int64() int64

func SecretKey ¶

func SecretKey() string

func ShortId ¶

func ShortId() string

Returns short, url-friendly Id

func ShortPassword ¶

func ShortPassword() string

Returns short, url-friendly Id

func String ¶ added in v1.49.26

func String(n int, alphabet string) string

String returns exactly n characters drawn uniformly from alphabet.

It is the primitive to reach for when the output has a shape someone will read back or type in — a referral code, a coupon — rather than base64 with the awkward characters filtered out afterwards. Filtering is what made referral codes "eight characters, unless the draw happened to contain four of '-' and '_', in which case seven or fewer".

Rejection sampling keeps the draw uniform. Folding a byte modulo the alphabet size would favour its first 256 % len(alphabet) characters, and a code with a lopsided alphabet is a code with less entropy than its length advertises.