brainfuck 0.5.0

A sample command-line Brainfuck interpreter.

A command-line Brainfuck interpreter implemented with Dart language.

Installation

You can install the command-line tool via dart pub. Just run the command below.

dart pub global activate brainfuck

Usage

brainfuck "YOUR_BRAINFUCK_CODE"

For example, to print "Hi":

brainfuck "++++++++++[>++++++++<-]>+++++++.---.--------------."

Technical Details

The Brainfuck Language

Brainfuck operates on an array of memory cells (this interpreter uses 65,535 cells, each initialized to zero) and a data pointer that starts at the first cell. The language has eight commands:

Command	Description
>	Move the data pointer to the next cell.
<	Move the data pointer to the previous cell.
+	Increment the value at the current cell by 1.
-	Decrement the value at the current cell by 1.
.	Output the byte at the current cell as an ASCII character.
,	Read one byte of input and store it in the current cell.
[	If the value at the current cell is zero, jump forward to the matching ].
]	If the value at the current cell is non-zero, jump back to the matching [.

Any other characters in the source string are treated as comments and ignored.

Interpreter Architecture

The interpreter works in two phases:

1. Compile – The compile() method parses the source string and converts it into an internal list of Instruction objects. During this phase the matching jump targets for [ and ] are pre-computed so that branching at runtime is an O(1) operation.
2. Run – The run() method executes the compiled instruction list. If compile() has not been called beforehand, run() calls it automatically.

Both methods return a Status value (Status.success or Status.failed). Compilation fails when a ] is encountered without a matching [.

Using the Library

The interpreter can be used as a Dart library:

import 'package:brainfuck/brainfuck.dart';

void main() {
  final interpreter = Brainfuck('++++++++++[>++++++++<-]>+++++++.---.--------------.');
  final status = interpreter.run();
  if (status == Status.failed) {
    print('Program failed to run.');
  }
}