PuduLangResilience.Randomizer

type: module path: "@root/src/PuduLangResilience/Randomizer.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.6 depth_status: MEDIUM tags: [module, seam] aliases: [PuduLangResilience.Randomizer]

Purpose

Uniform draws for jitter, injection rates, and weighted choices, replaceable by a seeded or fixed source in tests.

Interface

Signatures

export type Randomizer = { draw: fn(Int) -> Int }

export const SCALE: Int = 1000000000

export fn system() -> Randomizer

export fn seeded(seed: Int) -> Randomizer

export fn fixed(ratio: Decimal) -> Randomizer

export fn below(source: &Randomizer, bound: Int) -> Int

export fn fraction(source: &Randomizer) -> Int

export fn unit(source: &Randomizer) -> Float

export fn chance(source: &Randomizer, rate: Decimal) -> Bool

Linkage

• Requires: [[src/PuduLangResilience/Utils/Numeric]], [[src/PuduLangResilience/Utils/Shared]], Std.Decimal, Std.Random.
• Consumed by: [[src/PuduLangResilience/Chaos]], [[src/PuduLangResilience/Chaos/Weighted]], [[src/PuduLangResilience/Pipeline]], [[src/PuduLangResilience/Retry]], [[src/PuduLangResilience/Strategy]].

Algorithm

1. A randomizer answers a whole number below a bound; system and seeded keep a Std.Random generator under a lock.
2. fixed(r) always answers r of the bound, rounded down.
3. chance(rate) compares a draw in parts of SCALE (a billion) with the rate's parts; a rate of 0 never holds and 1 always does.

Negative Logic (Prohibited Paths)

• No draw is taken outside the bound, even from a custom draw function.

Edge Cases

• A bound below one answers zero; a fixed ratio is clamped to just below 1.

Depth

DEPTH 0.6 (MEDIUM). Tested by the suite mirroring this module under test/.

Grill Log

• Q: Why integer parts instead of floats? A: Rates are Decimal in the public surface and compare exactly against integer parts. _Rejected:_ float comparison (inexact at the rate boundaries tests pin).

Referenced by

[[seams/Runtime]] · [[src/PuduLangResilience/Chaos]] · [[src/PuduLangResilience/Chaos/Weighted]] · [[src/PuduLangResilience/Pipeline]] · [[src/PuduLangResilience/Retry]] · [[src/PuduLangResilience/Strategy]] · [[src/PuduLangResilience/Utils/Numeric]] · [[src/PuduLangResilience/Utils/Shared]] · [[src/PuduLangResilience/_MOC]]