HCoop / hcoop / debian / mlton.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f918cf1 CE |
1 | MLtonRandom |
| 2 | =========== | |
| 3 | ||
| 4 | [source,sml] | |
| 5 | ---- | |
| 6 | signature MLTON_RANDOM = | |
| 7 | sig | |
| 8 | val alphaNumChar: unit -> char | |
| 9 | val alphaNumString: int -> string | |
| 10 | val rand: unit -> word | |
| 11 | val seed: unit -> word option | |
| 12 | val srand: word -> unit | |
| 13 | val useed: unit -> word option | |
| 14 | end | |
| 15 | ---- | |
| 16 | ||
| 17 | * `alphaNumChar ()` | |
| 18 | + | |
| 19 | returns a random alphanumeric character. | |
| 20 | ||
| 21 | * `alphaNumString n` | |
| 22 | + | |
| 23 | returns a string of length `n` of random alphanumeric characters. | |
| 24 | ||
| 25 | * `rand ()` | |
| 26 | + | |
| 27 | returns the next pseudo-random number. | |
| 28 | ||
| 29 | * `seed ()` | |
| 30 | + | |
| 31 | returns a random word from `/dev/random`. Useful as an arg to | |
| 32 | `srand`. If `/dev/random` can not be read from, `seed ()` returns | |
| 33 | `NONE`. A call to `seed` may block until enough random bits are | |
| 34 | available. | |
| 35 | ||
| 36 | * `srand w` | |
| 37 | + | |
| 38 | sets the seed used by `rand` to `w`. | |
| 39 | ||
| 40 | * `useed ()` | |
| 41 | + | |
| 42 | returns a random word from `/dev/urandom`. Useful as an arg to | |
| 43 | `srand`. If `/dev/urandom` can not be read from, `useed ()` returns | |
| 44 | `NONE`. A call to `useed` will never block -- it will instead return | |
| 45 | lower quality random bits. |