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BrainHack is a Haskell implementation of the Brain-Flak language.
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compiler Fixes ascii mode Jul 11, 2017
.gitignore Improvements to speed, custom miniflak mode Jun 13, 2017
BrainHack.hs Fixes ascii mode Jul 11, 2017
Helpers.hs Improvements to speed, custom miniflak mode Jun 13, 2017
Interpreter.hs Mixed input is now allowed Jul 5, 2017
MiniInterpreter.hs Fixed cycle counting Jun 13, 2017


BrainHack is a Haskell implementation of the Brain-Flak language.

Running BrainHack

BrainHack can be run by compiling and running BrainHack.hs. This can be compiled with ghc:

$ ghc BrainHack.hs

To run a Brain-Flak program call the resulting binaries with the name of the file where the source is located and the arguments for the program.


$ ./BrainHack source.flk 1 3 6

Comparison to Rain-Flak

Here is a comparison between BrainHack and Rain-Flak (the standard Ruby interpreter)


BrainHack is much faster than Rain-Flak. Considerable testing puts the BrainHack at 50 times the speed of Rain-Flak.


BrainHack uses #{...} for block comments. While in Rain-Flak # comments out the rest of the line.

BrainHack requires braces to be balanced inside of comments, while Rain-Flak does not parse its comments.

ASCII input

BrainHack will automatically use ASCII input if you format your input as a string. For example

$BrainHack -e "({}())" '"String"'

BrainHack will also allow input of mixed types for example:

$BrainHack -e "({}())" 2 '"String"'

Will have both 2 and String as inputs.

Rain-Flak requires a -a flag to be passed to turn on ASCII input, mixed input is not allowed in Rain-Flak.


BrainHack has a full debugger using the @ syntax borrowed from Rain-Flak. However BrainHack uses slightly different flags than Rain-Flak. For a detailed comparison run both of the interpreters with the -H option.

Both interpreters have flags that are unique to the specific interpreter however Rain-Flak has more.

Miniflak Optimizations

While both interpreters can run Miniflak code, BrainHack has special optimizations to make Miniflak faster when run.

Additional Languages

BrainHack only supports Vanilla Brain-Flak and Miniflak (not all features are available with Miniflak), while Rain-Flak supports, Vanilla, Mini-flak, Brain-Flak Classic and Brain-Flueue, all with full features.

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