Random.int low byte always zero for large ranges in Core 5.1.1

[electronjoe]

I came across this when verifying the randomness of my Elm application. I was using Random.Generate - but this caused me to explore in the REPL - and demonstrated unexpected behavior.

Note in the random output examples below
1870605312 = 0x6F7F2C00
-40506368 = 0xFD95EC00

In experimentation - all outputs appear to be 24 bits of randomness with a low byte of zero? Unless I'm somehow abusing things.

Random.step (Random.int Random.minInt Random.maxInt) (Random.initialSeed 352342343451)
(1870605312,Seed { state = State 271757466 483020887, next = , split = , range = })
: ( Int, Random.Seed )
Random.step (Random.int 0 Random.maxInt) (Random.initialSeed 352342343451)
(1870605312,Seed { state = State 271757466 483020887, next = , split = , range = })
: ( Int, Random.Seed )
Random.step (Random.int Random.minInt Random.maxInt) (Random.initialSeed 352342342)
(-40506368,Seed { state = State 1784235513 1655838864, next = , split = , range = })
: ( Int, Random.Seed )

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[electronjoe]

Additional information:
Browser: Chrome 61.0.3163.100 (Official Build) (64-bit)
OS: OSX Sierra 10.12.6

[electronjoe]

Additional information:
Browser: Chrome 61.0.3163.100 (Official Build) (64-bit)
OS: OSX Sierra 10.12.6

[electronjoe]

Wanted to follow up for people who might come across this. I understand that mgold/elm-random-pcg is going to become mainline soon? I migrated to mgold/elm-random-pcg, it was completely API compatible with Core.Random - and resolved my issue.

[electronjoe]

Wanted to follow up for people who might come across this. I understand that mgold/elm-random-pcg is going to become mainline soon? I migrated to mgold/elm-random-pcg, it was completely API compatible with Core.Random - and resolved my issue.

[evancz]

Yes, that library will be in core in the next release of Elm. Using Max's library is a nice thing to do in the meantime.

[evancz]

Yes, that library will be in core in the next release of Elm. Using Max's library is a nice thing to do in the meantime.