BrainBash
A fast Brainf**k interpreter in pure Bash
I leaf@home ~/g/c/s/BrainBash> cat programs/optimize.bf
+++++ +++++ +++++ +++++ +++++
[ - > +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ < ]
>
[ - >>>>> +++++ +++++ +++++ <<<<< ]
I leaf@home ~/g/c/s/BrainBash> bash tm.sh -q -p -P -O programs/optimize.bf
program: 25+50_1A>15_5A
optimzed away 96.33% of instructions; 2625% speed up
tape : 0 0 0 0 0 0 18750
% time : instruction(s)
----------------------------------------------
100.00 : 25+50_1A>15_5A
Bash?
Yes, tm.sh is a 600+ line Bash script. Why Bash? The language actually lends itself fairly well to this kind of problem space - working with text. Even if you're not interested in Brainf**k, tm.sh showcases a wide variety of advanced Bash features such as:
- process substitution
- parameter substitution
- arrays
- built ins
- globs
Features
tm.sh provides a number of features:
- interactive interpreter
- extensive optimizations
- colorized execution tracing
- compilation, in the way of saving optimizations for later
- built in execution profiler
Options
tm.sh provides a number of options:
leaf@home ~/g/c/s/BrainBash> bash tm.sh --help
usage: bash tm.sh [OPTION]... input_file
-c --compile no execution, write parsed, optimized program to file
-h --help show help information
-i --max_iter x number of operations to run before early stopping
-p --print print out the program before execution
-P --profile show instruction execution information
-o --optimize apply basic optimizations
-O --Optimize apply advanced, heavy optimizations
-q --quiet suppress execution trace
-r --raw treat input as already parsed, use with compiled programs
-s --stime x sleep for x seconds between operations
-S --step only advance execution when user presses enter
Fast start
git clone https://github.com/Gandalf-/BrainBash.git
cd BrainBash
bash tm.sh -q programs/hello_world.bf
Example usage:
These snippets show an example program including user input and the results of different levels of optimizations. You'll notice that the first run was cut short. tm.sh by default limits execution to 1,000,000 instructions.
leaf@home ~/g/c/s/BrainBash> time bash tm.sh -p -q programs/fibonacci.bf
program: +>+>>>>,[<<<<<[->>+>+<<<]>>>[<<<+>>>-]<<[->>+>+<<<]>>>[-<<<+>>>]<[-<+>]>>[->+<]>-]
input?> 20
tape : 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 2683 6765 10946 8263 1
real 0m53.749s
user 0m43.664s
sys 0m5.764s
leaf@home ~/g/c/s/BrainBash> time bash tm.sh -p -q -o programs/fibonacci.bf
program: +>+4>,[5<[-2>+>+3<]3>[3<+3>-]2<[-2>+>+3<]3>[-3<+3>]<[-<+>]2>[->+<]>-]
optimized away 32.9300% of instructions; 49% speed up
input?> 20
tape : 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711 0 0 0 0
real 0m48.181s
user 0m39.615s
sys 0m6.472s
leaf@home ~/g/c/s/BrainBash> time bash tm.sh -p -q -O programs/fibonacci.bf
program: +>+4>,[5<2_1_1C3>3a2<2_1_1C3>3a<1a2>1A>-]
optimized away 74.4000% of instructions; 290% speed up
input?> 20
tape : 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711 0 0 0 0
real 0m0.985s
user 0m0.093s
sys 0m0.085s
Example profiler usage:
These snippets show some example output from using the program profiler. The program's execution is broken into contiguous sequences of operations that are all run the same number of times. Indentation corresponds to the level of loop depth.
leaf@home ~/g/c/s/BrainBash> bash tm.sh --quiet --profile --print programs/fibonacci.bf
program: +>+>>>>,[<<<<<[->>+>+<<<]>>>[<<<+>>>-]<<[->>+>+<<<]>>>[-<<<+>>>]<[-<+>]>>[->+<]>-]
input?> 10
tape : 1 1 2 3 5 8 13 21 34 55 89 144 0 0 0 0
% time : instuction(s)
----------------------------------------------
0.08 : +>+>>>>,
0.64 : [<<<<<
16.30 : [->>+>+<<<]
0.32 : >>>
14.82 : [<<<+>>>-]
0.21 : <<
25.62 : [->>+>+<<<]
0.32 : >>>
23.29 : [-<<<+>>>]
0.11 : <
13.97 : [-<+>]
0.21 : >>
3.81 : [->+<]
0.32 : >-]
leaf@home ~/g/c/s/BrainBash> bash tm.sh --quiet --profile --print --Optimize programs/fibonacci.bf
program: +>+4>,[5<2_1_1C3>3a2<2_1_1C3>3a<1a2>1A>-]
optimized away 74.4000% of instructions; 290% speed up
input?> 20
tape : 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711 0 0 0 0
% time : instuction(s)
----------------------------------------------
1.47 : +>+4>,
98.53 : [5<2_1_1C3>3a2<2_1_1C3>3a<1a2>1A>-]