# 1.2.0 1. Breaking change which mostly maintains backwards compatibility, see "Breaking Changes" below. 2. Support for monadic generators e.g. [mwc-random](https://hackage.haskell.org/package/mwc-random). 3. Monadic adapters for pure generators (providing a uniform monadic interface to pure and monadic generators). 4. Faster in all cases except one by more than x18 (N.B. x18 not 18%) and some cases (depending on the type) faster by more than x1000 - see below for benchmarks. 5. Passes a large number of random number test suites: * [dieharder](http://webhome.phy.duke.edu/~rgb/General/dieharder.php "venerable") * [TestU01 (SmallCrush, Crush, BigCrush)](http://simul.iro.umontreal.ca/testu01/tu01.html "venerable") * [PractRand](http://pracrand.sourceforge.net/ "active") * [gjrand](http://gjrand.sourceforge.net/ "active") * See [random-quality](https://github.com/tweag/random-quality) for details on how to do this yourself. 6. Better quality split as judged by these [tests](https://www.cambridge.org/core/journals/journal-of-functional-programming/article/evaluation-of-splittable-pseudorandom-generators/3EBAA9F14939C5BB5560E32D1A132637). Again see [random-quality](https://github.com/tweag/random-quality) for details on how to do this yourself. 7. Unbiased generation of ranges. 8. Updated tests and benchmarks. 9. [Continuous integration](https://travis-ci.org/github/haskell/random). ### Breaking Changes Version 1.2.0 introduces these breaking changes: * requires `base >= 4.8` (GHC-7.10) * `StdGen` is no longer an instance of `Read` * `randomIO` and `randomRIO` were extracted from the `Random` class into separate functions In addition, there may be import clashes with new functions, e.g. `uniform` and `uniformR`. ### Deprecations Version 1.2.0 introduces `genWord64`, `genWord32` and similar methods to the `RandomGen` class. The significantly slower method `next` and its companion `genRange` are now deprecated. ### Issues Addressed Issue Number | Description | Comment --------------|-------------|-------- [25](https://github.com/haskell/random/issues/25) | The seeds generated by split are not independent | Fixed: changed algorithm to SplitMix, which provides a robust split operation [26](https://github.com/haskell/random/issues/26) | Add Random instances for tuples | Addressed: added `Uniform` instances for up to 6-tuples [44](https://github.com/haskell/random/issues/44) | Add Random instance for Natural | Addressed: added UniformRange instance for Natural [51](https://github.com/haskell/random/issues/51) | Very low throughput | Fixed: see benchmarks below [53](https://github.com/haskell/random/issues/53) | incorrect distribution of randomR for floating-point numbers | (\*) [55](https://github.com/haskell/random/issues/55) | System/Random.hs:43:1: warning: [-Wtabs] | Fixed: No more tabs [58](https://github.com/haskell/random/issues/58) | Why does random for Float and Double produce exactly 24 or 53 bits? | (\*) [59](https://github.com/haskell/random/issues/59) | read :: StdGen fails for strings longer than 6 | Addressed: StdGen is no longer an instance of Read #### Comments (\*) 1.2 samples more bits but does not sample every `Float` or `Double`. There are methods to do this but they have some downsides; see [here](https://github.com/idontgetoutmuch/random/issues/105) for a fuller discussion. ## Benchmarks Here are some benchmarks run on a 3.1 GHz Intel Core i7. The full benchmarks can be run using e.g. `stack bench`. The benchmarks are measured in milliseconds per 100,000 generations. In some cases, the performance is over x1000 times better; the minimum performance increase for the types listed below is more than x36. Name | 1.1 Mean | 1.2 Mean ------------|----------|---------- Float | 27.819 | 0.305 Double | 50.644 | 0.328 Integer | 42.332 | 0.332 Word | 40.739 | 0.027 Int | 43.847 | 0.028 Char | 17.009 | 0.462 Bool | 17.542 | 0.027 # 1.1 * breaking change to `randomIValInteger` to improve RNG quality and performance see https://github.com/haskell/random/pull/4 and ghc https://ghc.haskell.org/trac/ghc/ticket/8898 * correct documentation about generated range of Int32 sized values of type Int https://github.com/haskell/random/pull/7 * fix memory leaks by using strict fields and strict atomicModifyIORef' https://github.com/haskell/random/pull/8 related to ghc trac tickets #7936 and #4218 * support for base < 4.6 (which doesnt provide strict atomicModifyIORef') and integrating Travis CI support. https://github.com/haskell/random/pull/12 * fix C type in test suite https://github.com/haskell/random/pull/9 # 1.0.1.1 bump for overflow bug fixes # 1.0.1.2 bump for ticket 8704, build fusion # 1.0.1.0 bump for bug fixes, # 1.0.0.4 bumped version for float/double range bugfix