x/mtrand@v1.0.0/mod.ts

mt19937 for Deno
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// cast number to unsigned 32-bit intexport const castUint32 = (n: number) => { return new Uint32Array([n])[0];};
const _mtrand = function* (seed: number) { // parameters c++ ref // http://www.cplusplus.com/reference/random/mt19937/ const W = 32; const N = 624; const M = 397; const F = 1812433253; const U = 11; const D = 0xffffffff; const S = 7; const B = 0x9d2c5680; const T = 15; const C = 0xefc60000; const L = 18; const R = 31; const HI = (1 << R); const LO = (1 << R) - 1; const MASK = 0x9908b0df;
let index: number; const mt = [];
// init mt[0] = castUint32(seed); for (index = 1; index < N; index++) { let x: any = mt[index - 1] ^ (mt[index - 1] >>> 30); mt[index] = castUint32( ((((x & 0xffff0000) >>> 16) * F) << 16) + ((((x & 0x0000ffff) >>> 0) * F) << 0) + index, ); }
// main do { for (index = 0; index < N; index++) { const x = castUint32((mt[index] & HI) + (mt[(index + 1) % N] & LO)); mt[index] = (mt[(index + M) % N] ^ x >>> 1); mt[index] = castUint32(x & 1 ? mt[index] ^ MASK : mt[index]); }
for (index = 0; index < N; index++) { let y = mt[index]; y ^= (y >>> U); y ^= (y << S) & B; y ^= (y << T) & C; y ^= (y >>> L); yield castUint32(y); } } while (true);};
export const mtrand = (seed: any) => { return _mtrand(seed);};
// ToDo add a couple of methods