Get the current state of the pseudorandom generator:

Use a RandomGeneratorState object to seed BlockRandom:

Seed the current random generator and save the resulting state:

A particular sequence of numbers is generated:

Reseed using the RandomGeneratorState object:

The same sequence of numbers is generated:

Some methods have states that can only be restored in the same session:

SeedRandom will work as expected in the same kernel session:

Trying to restore these states in a new kernel session will restore the method but not the state:

Some methods do not have a restorable state:

SeedRandom can use these to set the method, but random sequences will not be reproduced:

Programmatically extract the method name:

Programmatically determine whether the state survives the end of the kernel session:

Create a version of BlockRandom that refuses to run if the current random state cannot be restored:

Activate a randomness generation method with no restorable state:

Because this method cannot be seeded, BlockRandom cannot give reproducible results:

The function will refuse to evaluate:

Activate a randomness generation method that possesses a restorable state:

The function restores the random state at the end of each evaluation:

Hence the following result matches the previous result:

When available, the state hash is returned as an integer:

If the state hash has expired, it is returned as None:

The current random generator state is stored in $RandomGeneratorState:

SeedRandom returns a RandomGeneratorState object:

A RandomGeneratorState object can be used as a seed in SeedRandom and related functions:

Use state in SeedRandom:

Use it to seed computations in BlockRandom:

When a session-only RandomGeneratorState object is given to SeedRandom, a copy is created:

This copy has a different session hash:

However, both RandomGeneratorState objects produce the same random sequences: