tinybf

A minuscule interpreter for the Brainfuck programming language, written in Ruby.

Some of the features/design decisions:

• Matches and caches brackets before executing code, speeding up the interpretation.
• Has an array of 1-byte unsigned cells that can grow "infinitely" to the right.
• Wraps cell values if they exceed the minimum/maximum allowed.
• Ignores a < command if the array pointer is on the left-most cell.
• Passes Daniel Cristofani's tests and follows his Epistle to the Implementors closely.
• Weighs only 382 bytes!

Usage

Apart from the eight standard Brainfuck commands, the first exclamation mark (!) is significant and is used to tell apart the program being interpreted from its input.

Here's a usage example with Daniel Cristofani's numwarp.b:

>>>>+>+++>+++>>>>>+++[>,+>++++[>++++<-]>[<<[-[->]]>[<]>-]<<[>+>+>>+>+[<<<<]<+>>[
+<]<[>]>+[[>>>]>>+[<<<<]>-]+<+>>>-[<<+[>]>>+<<<+<+<--------[<<-<<+[>]>+<<-<<-[<<
<+<-[>>]<-<-<<<-<----[<<<->>>>+<-[<<<+[>]>+<<+<-<-[<<+<-<+[>>]<+<<<<+<-[<<-[>]>>
-<<<-<-<-[<<<+<-[>>]<+<<<+<+<-[<<<<+[>]<-<<-[<<+[>]>>-<<<<-<-[>>>>>+<-<<<+<-[>>+
<<-[<<-<-[>]>+<<-<-<-[<<+<+[>]<+<+<-[>>-<-<-[<<-[>]<+<++++[<-------->-]++<[<<+[>
]>>-<-<<<<-[<<-<<->>>>-[<<<<+[>]>+<<<<-[<<+<<-[>>]<+<<<<<-[>>>>-<<<-<-]]]]]]]]]]
]]]]]]]]]]]]>[>[[[<<<<]>+>>[>>>>>]<-]<]>>>+>>>>>>>+>]<]<[-]<<<<<<<++<+++<+++[[>]
>>>>>>++++++++[<<++++>++++++>-]<-<<[-[<+>>.<-]]<<<<[-[-[>+<-]>]>>>>>[.[>]]<<[<+>
-]>>>[<<++[<+>--]>>-]<<[->+<[<++>-]]<<<[<+>-]<<<<]>>+>>>--[<+>---]<.>>[[-]<<]<]
!1337
      /\
        \
    /\
     /\
  /\  /
   /\
 \  /
  \

In the example above, 1337 is the input to the interpreted program (everything before the !).

Limitations

• Insanely slow compared to a C implementation.
• No error checking (e.g. unmatched brackets).
• Both a program's code and its input are passed through the same stream (stdin); this makes I/O non-interactive.
• The code is obfuscated and unreadable.

License

The MIT License

Copyright (c) 2010 Aggelos Orfanakos

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Author

Aggelos Orfanakos, http://agorf.gr/