2.1 SeedLib: seed generators

Chapter 2: Core libraries · Section 1 · Guide map

SeedLib is the state layer. It does not offer a NextInt(min, max) method or shuffle a list. A seed generator implements RandEXom.Interface.ISeedR and exposes init (original input), now (current state), previous (state before the latest advance), and Next() to advance. A RandomLib source consumes that state and provides bounded draws; a Framework helper can then use those draws. See the layer diagram and class index.

Choose	When you need
`XORShift64Seed`	The default progression of `ModuloRandom` or explicit xorshift variants
`LCGSeedR`	A parameterized LCG or historical preset
`IterativeSeedR`	A simple built-in update operation
`IterativeSeedRCustom`	Your own state-update function
`SeedR`	Constant state inside library defaults; not publicly constructible

The source decides when to call Next(). For example, ModuloRandom advances the seed before each raw draw, whereas SSRNGRandom reads a state digit and then advances. Therefore, swapping the source while retaining the same ISeedR is not sequence-preserving.

using RandEXom.RandomLib;
using RandEXom.SeedLib;

var seed = new LCGSeedR(LCGSeedR.ParameterTemplate.Numerical_Recipes, seed: 42);
var random = new ModuloRandom(seed);
int value = random.NextInt(0, 10);

If you omit a seed, each class chooses one from the current time. Provide an explicit seed when you need a reproducible sequence. The same initial seed is not enough to make different algorithms produce identical output.

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