PCG Random Number Generator, AVM Edition

lib-pcg-algots

This AlgoKit subproject implements PCG in Algorand TypeScript.
For more general info on this library, see the main page.

Getting Started

Install lib-pcg-algots in your project. Using npm, this looks like:

``bash
npm add lib-pcg-algots
`

The typical use case of using the library to generate a sequence of pseudo-random numbers looks like:

`typescript
import { Contract, assert, Global, Txn } from '@algorandfoundation/algorand-typescript'
import { StaticArray, DynamicArray, Byte, UintN, baremethod } from '@algorandfoundation/algorand-typescript/arc4'
import { pcg32Init, pcg32Random } from 'lib-pcg-algots/lib_pcg/pcg32.algo'

export class YourContract extends Contract {
public bounded_rand_uint32(...): ... {
// Here you would acquire a safe randomness seed
const seed = ...

// Seed the PRNG
const state = pcg32Init(seed)

// Generate a sequence
const [newState, sequence] = pcg32Random(state, , , )

// The rest of your program
...
}
}
`

You can also take a look at the exposer contracts:

[1,
2,
3
]

Usage

All generators all use pcgInit() for seeding the algorithm.

To generate a sequence, use pcgRandom().

You can pass non-zero lowerBound and upperBound arguments to pcgRandom() to get integers in a desired range.
Note that:

- lowerBound is always included in your range.
- upperBound is always excluded by your range.
- You can set them independently.
- The range should be at least two elements wide.

When either bound is set to zero, that bound is not applied.

Feature Support

- [x] Package published on npm
- [x] 8 / 16 / 32-bit generator
- [x] 64-bit generator
- [x] 128`-bit generator