emprng: an Erlang/OTP Multiple PRNG suite aka rand module

Note well: no further development

No further development after Version 1.0.0 (as in OTP 20) in this repository.

Dan Gudmundsson has made significant improvements and changes between OTP 19 and 20. Refer to Erlang/OTP official source code for the further details.

Target files

Under src/

• rand.erl: OTP random-compatible module (lib/stdlib/src/rand.erl)

Under test/

• rand_SUITE.erl: OTP rand test suite (lib/stdlib/test/rand_SUITE.erl)

Under xml-doc/

• rand.xml: OTP rand manual (lib/stdlib/doc/src/rand.xml)

Other directories

• c-example/: C code for calculating Xorshift*/+ test values
• test-scripts: Erlang escript code for verifying Xorshift*/+ test values

License

• See individual files for the license details
• rand.erl is licensed under Apache Public License 2.0

Version

• 1.0.0
• See the Git tag for the details

Requirements

• Erlang/OTP 20
• (Use tag 0.2.1 to retrieve the last code for OTP 17.x)
• (Use tag 0.4.0 to retrieve the last code for OTP 18.x)
• (Use tag 0.5.0 to retrieve the last code for OTP 19.0.x)
• (Use tag 0.9.2 to retrieve the last code for OTP 19.3.x)

How to build

make distclean  # Total cleanup
make            # Compile BEAM files
make tests      # Run Common Test cases
make dialyze    # check specs

Current goals

• Bugfix

Completed goals

• Provide a substitute of Erlang/OTP random module
• Maintain full backward compatibility (seeding is semantically streamlined than random module)
• Extendable (accepting arbitrary algorithms)
• Write in pure Erlang
• Comply with the coding convention of Erlang/OTP stdlib modules
• Jump functions

Non-goals

• NIFs (maybe a future goal, rand.erl is already capable to handle arbitrary functions/modules)

PRNGs available as external modules

Refer to the Erlang/OTP rand module manual for the further details of the available algorithms.

• exsplus116 (Xorshift116+, default PRNG) (the original exsplus was Xorshift128+) (exsplus116 is available since 0.4.0)
• exs64 (Xorshift64*)
• exs1024 (Xorshift1024*)

Acknowledgments

Thanks to Dan Gudmundsson for the idea of allowing multiple PRNG handlers to the OTP random module, including the code review, various ideas, implementations, pieces of code for rand.erl and rand_SUITE.erl, and comments.

Thanks to Guilherme Andrade for adding cryptographically strong rand plugins and other contributions.

Thanks to Raimo Niskanen for adding xoroshiro116+, supervising the code for OTP 20, and other contributions.

Thanks to Sebastiano Vigna for providing xorshift116+ and xoroshiro116+ algorithms.

Thanks to Mutsuo Saito and Makoto Matsumoto, the SFMT and TinyMT authors, for allowing redistribution of sfmt-erlang and tinymt-erlang under Erlang Public License.

Thanks to Erlang Solutions for giving me the talk about this repository at Erlang Factory SF Bay Area 2015, Erlang User Conference 2016, and Erlang and Elixir Factory SF Bay Area 2017.