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| author | Camil Staps | 2016-02-02 19:24:50 +0100 |
|---|---|---|
| committer | Camil Staps | 2016-02-02 19:24:50 +0100 |
| commit | a7d7542dc646a5fd124ef71e71ce260889f1701b (patch) | |
| tree | 04ed89503bbb3cc9933273a1326a53ca724c3492 /1415/fp2/week1/mart/Random.icl | |
| parent | week6 camil: working positioning of lines by putting empties at left and righ... (diff) | |
Diffstat (limited to '1415/fp2/week1/mart/Random.icl')
| -rw-r--r-- | 1415/fp2/week1/mart/Random.icl | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/1415/fp2/week1/mart/Random.icl b/1415/fp2/week1/mart/Random.icl new file mode 100644 index 0000000..b6e0768 --- /dev/null +++ b/1415/fp2/week1/mart/Random.icl @@ -0,0 +1,20 @@ +implementation module Random + +import StdFile, StdList, StdMisc, StdArray, Random + +:: RandomSeed :== Int + +nullRandomSeed :: RandomSeed +nullRandomSeed = 0 + +getNewRandomSeed :: !*env -> (!RandomSeed, !*env) | FileSystem env +getNewRandomSeed env +# (ok, src, env) = sfopen "/dev/urandom" FReadData env +| not ok => abort "could not open /dev/urandom" +# (bytes, src) = sfreads src 4 + seed = foldl (\x y->(x<<8)+toInt y) 0 [c \\ c<-:bytes] +| otherwise => (seed, env) + +random :: !RandomSeed -> .(!Int, !RandomSeed) +random seed = (seed>>16 bitand 0xFFFF, seed*0x08088405+1) + |