Execute Brain****
You are encouraged to solve this task according to the task description, using any language you may know.
RCBF is a set of Brainf*** compilers and interpreters written for Rosetta Code in a variety of languages. Below are links to each of the versions of RCBF.
An implementation need only properly implement the '[', ']', '+', '-', '<', '>', ',', and '.' instructions. Any cell size is allowed, EOF support is optional, as is whether you have bounded or unbounded memory.
ALGOL 68
Ada
AutoHotkey
BASIC
Implementation in BASIC (QuickBasic dialect).
Brat
C
C#
C++
Clojure
<lang clojure>(ns brainfuck)
(def *input*)
(def *output*)
(defrecord Data [ptr cells])
(defn inc-ptr [next-cmd]
(fn [data] (next-cmd (update-in data [:ptr] inc))))
(defn dec-ptr [next-cmd]
(fn [data] (next-cmd (update-in data [:ptr] dec))))
(defn inc-cell [next-cmd]
(fn [data] (next-cmd (update-in data [:cells (:ptr data)] (fnil inc 0)))))
(defn dec-cell [next-cmd]
(fn [data] (next-cmd (update-in data [:cells (:ptr data)] (fnil dec 0)))))
(defn output-cell [next-cmd]
(fn [data] (set! *output* (conj *output* (get (:cells data) (:ptr data) 0))) (next-cmd data)))
(defn input-cell [next-cmd]
(fn [data] (let [[input & rest-input] *input*] (set! *input* rest-input) (next-cmd (update-in data [:cells (:ptr data)] input)))))
(defn if-loop [next-cmd loop-cmd]
(fn [data] (next-cmd (loop [d data] (if (zero? (get (:cells d) (:ptr d) 0)) d (recur (loop-cmd d)))))))
(defn terminate [data] data)
(defn split-cmds [cmds]
(letfn [(split [[cmd & rest-cmds] loop-cmds] (when (nil? cmd) (throw (Exception. "invalid commands: missing ]"))) (case cmd \[ (let [[c l] (split-cmds rest-cmds)] (recur c (str loop-cmds "[" l "]"))) \] [(apply str rest-cmds) loop-cmds] (recur rest-cmds (str loop-cmds cmd))))] (split cmds "")))
(defn compile-cmds cmd & rest-cmds
(if (nil? cmd) terminate (case cmd \> (inc-ptr (compile-cmds rest-cmds)) \< (dec-ptr (compile-cmds rest-cmds)) \+ (inc-cell (compile-cmds rest-cmds)) \- (dec-cell (compile-cmds rest-cmds)) \. (output-cell (compile-cmds rest-cmds)) \, (input-cell (compile-cmds rest-cmds)) \[ (let [[cmds loop-cmds] (split-cmds rest-cmds)] (if-loop (compile-cmds cmds) (compile-cmds loop-cmds))) \] (throw (Exception. "invalid commands: missing [")) (compile-cmds rest-cmds))))
(defn compile-and-run [cmds input]
(binding [*input* input *output* []] (let [compiled-cmds (compile-cmds cmds)] (println (compiled-cmds (Data. 0 {})))) (println *output*) (println (apply str (map char *output*)))))
</lang> <lang clojure>brainfuck> (compile-and-run "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>." []) {:ptr 4, :cells {4 10, 3 33, 2 100, 1 87, 0 0}} [72 101 108 108 111 32 87 111 114 108 100 33 10] Hello World!
nil </lang>
Common Lisp
Implementation in Common Lisp.
D
Alternative version, simpler and faster: <lang d>import core.stdc.stdio: getchar, putchar, EOF; import core.stdc.stdlib: exit;
void brainfuckRun(const string code) {
static pure int[int] matchBraces(const string code) out(result) { foreach (k, v; result) { assert(k >=0 && k < code.length); assert(v >=0 && v < code.length); assert(v in result); } } body { int[int] loops; int[] loopStack;
foreach (i, instruction; code) { if (instruction == '[') loopStack ~= i; else if (instruction == ']') { assert(loopStack.length); loops[i] = loopStack[$ - 1]; loopStack.length -= 1; loops[loops[i]] = i; } }
assert(!loopStack.length); return loops; }
static void runCode(const string code, const int[int] loops) { enum char empty = '\0'; char[30_000] tape = empty; int cell, index;
while (index < cast(int)code.length) { immutable int instruction = code[index];
switch (instruction) { case '>': cell++; assert(cell < tape.length); break; case '<': cell--; assert(cell >= 0); break; case '+': tape[cell]++; break; case '-': tape[cell]--; break; case '.': putchar(tape[cell]); break; case ',': int c = getchar(); if (c == EOF) exit(1); tape[cell] = cast(char)c; break; case '[': if (tape[cell] == empty) index = loops[index]; break; case ']': if (tape[cell] != empty) index = loops[index]; break; default: break; }
index++; } }
int[int] loops = matchBraces(code); runCode(code, loops);
}
void main() {
brainfuckRun("++++++++++[>+++++++>++++++++++>+++>+<<<<-] >++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.");
}</lang> Faster partially compile-time version (code generated at compile-time, run at run time): <lang d>import core.stdc.stdio, core.stdc.stdlib;
pure string ctbf(in string code) {
string r; foreach (c; code) switch (c) { case '>': r ~= "i++; assert(i < m.length);"; break; case '<': r ~= "i--; assert(i >= 0);"; break; case '+': r ~= "m[i]++;"; break; case '-': r ~= "m[i]--;"; break; case '[': r ~= "while (m[i]) {"; break; case ']': r ~= "}"; break; case '.': r ~= "putchar(m[i]);"; break; case ',': r ~= "int d = getchar(); if (d == EOF) exit(1); tape[cell] = cast(char)d;"; break; default: break; } return r;
}
void main() {
char[30_000] m = '\0'; size_t i; mixin(ctbf("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++ ++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."));
}</lang>
E
Erlang
Forth
F#
GAP
<lang gap># Here . and , print and read an integer, not a character Brainfuck := function(prog)
local pointer, stack, leftcells, rightcells, instr, stackptr, len, output, input, jump, i, j, set, get; input := InputTextUser(); output := OutputTextUser(); instr := 1; pointer := 0; leftcells := [ ]; rightcells := [ ]; stack := [ ]; stackptr := 0; len := Length(prog); jump := [ ];
get := function() local p; if pointer >= 0 then p := pointer + 1; if IsBound(rightcells[p]) then return rightcells[p]; else return 0; fi; else p := -pointer; if IsBound(leftcells[p]) then return leftcells[p]; else return 0; fi; fi; end; set := function(value) local p; if pointer >= 0 then p := pointer + 1; if value = 0 then Unbind(rightcells[p]); else rightcells[p] := value; fi; else p := -pointer; if value = 0 then Unbind(leftcells[p]); else leftcells[p] := value; fi; fi; end; # find jumps for faster execution for i in [1 .. len] do if prog[i] = '[' then stackptr := stackptr + 1; stack[stackptr] := i; elif prog[i] = ']' then j := stack[stackptr]; stackptr := stackptr - 1; jump[i] := j; jump[j] := i; fi; od;
while instr <= len do c := prog[instr]; if c = '<' then pointer := pointer - 1; elif c = '>' then pointer := pointer + 1; elif c = '+' then set(get() + 1); elif c = '-' then set(get() - 1); elif c = '.' then WriteLine(output, String(get())); elif c = ',' then set(Int(Chomp(ReadLine(input)))); elif c = '[' then if get() = 0 then instr := jump[instr]; fi; elif c = ']' then if get() <> 0 then instr := jump[instr]; fi; fi; instr := instr + 1; od; CloseStream(input); CloseStream(output); # for debugging purposes, return last state return [leftcells, rightcells, pointer];
end;
- An addition
Brainfuck("+++.<+++++.[->+<]>.");
- 3
- 5
- 8</lang>
Go
Fixed size data store, no bounds checking. <lang go>package main
import "fmt"
func main() {
// example program is current Brain**** solution to // Hello world/Text task. only requires 10 bytes of data store! bf(10, `++++++++++[>+>+++>++++>+++++++>++++++++>+++++++++>++
++++++++>+++++++++++>++++++++++++<<<<<<<<<-]>>>>+.>>> >+..<.<++++++++.>>>+.<<+.<<<<++++.<++.>>>+++++++.>>>.+++. <+++++++.--------.<<<<<+.<+++.---.`) }
func bf(dLen int, is string) {
ds := make([]byte, dLen) // data store var dp int // data pointer for ip := 0; ip < len(is); ip++ { switch is[ip] { case '>': dp++ case '<': dp-- case '+': ds[dp]++ case '-': ds[dp]-- case '.': fmt.Printf("%c", ds[dp]) case ',': fmt.Scanf("%c", &ds[dp]) case '[': if ds[dp] == 0 { for nc := 1; nc > 0; { ip++ if is[ip] == '[' { nc++ } else if is[ip] == ']' { nc-- } } } case ']': if ds[dp] != 0 { for nc := 1; nc > 0; { ip-- if is[ip] == ']' { nc++ } else if is[ip] == '[' { nc-- } } } } }
}</lang> Output:
Goodbye, World!
Haskell
Icon and Unicon
Implementation in Icon/Unicon.
J
Java
JavaScript
Lua
Modula-3
Nimrod
<lang nimrod> import strutils
proc jumpBackward(pos: var int, program: string) =
var level = 1 while pos > 0 and level != 0: dec pos case program[pos] of '[': dec level of ']': inc level else: discard 1 dec pos
proc jumpForward(pos: var int, program: string) =
var level = 1 while pos < program.len and level != 0: inc pos case program[pos] of ']': inc level of '[': dec level else: discard 1
proc bf(program: string) =
var tape: array[0..20, int] var pointer = 0 var pos = 0 var indent = 0
while pos < program.len: var token = program[pos] case token of '+': inc tape[pointer] of '-': dec tape[pointer] of ',': tape[pointer] = int(stdin.readChar()) of '.': stdout.write(chr(tape[pointer])) of '[': if tape[pointer] == 0: jumpForward(pos, program) of ']': if tape[pointer] != 0: jumpBackward(pos, program) of '>': inc pointer of '<': dec pointer else: discard 1 inc pos
var addition = ",>++++++[<-------->-],[<+>-]<." var hello_world = "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."
bf(addition)
- bf(hello_world)
</lang>
OCaml
Perl
Perl 6
PHP
See also this alternate implementation.
<lang php><?php function brainfuck_interpret(&$s, &$_s, &$d, &$_d, &$i, &$_i, &$o) {
do { switch($s[$_s]) { case '+': $d[$_d] = chr(ord($d[$_d]) + 1); break; case '-': $d[$_d] = chr(ord($d[$_d]) - 1); break; case '>': $_d++; if(!isset($d[$_d])) $d[$_d] = chr(0); break; case '<': $_d--; break; case '.': $o .= $d[$_d]; break; case ',': $d[$_d] = $_i==strlen($i) ? chr(0) : $i[$_i++]; break; case '[': if((int)ord($d[$_d]) == 0) { $brackets = 1; while($brackets && $_s++ < strlen($s)) { if($s[$_s] == '[') $brackets++; else if($s[$_s] == ']') $brackets--; } } else { $pos = $_s++-1; if(brainfuck_interpret($s, $_s, $d, $_d, $i, $_i, $o)) $_s = $pos; } break; case ']': return ((int)ord($d[$_d]) != 0); } } while(++$_s < strlen($s));
}
function brainfuck($source, $input=) {
$data = array(); $data[0] = chr(0); $data_index = 0; $source_index = 0; $input_index = 0; $output = ; brainfuck_interpret($source, $source_index, $data, $data_index, $input, $input_index, $output); return $output;
} ?> </lang>
PicoLisp
This solution uses a doubly-linked list for the cell space. That list consists of a single cell initially, and grows automatically in both directions. The value in each cell is unlimited. <lang PicoLisp>(off "Program")
(de compile (File)
(let Stack NIL (setq "Program" (make (in File (while (char) (case @ (">" (link '(setq Data (or (cddr Data) (con (cdr Data) (cons 0 (cons Data))) ) ) ) ) ("<" (link '(setq Data (or (cadr Data) (set (cdr Data) (cons 0 (cons NIL Data))) ) ) ) ) ("+" (link '(inc Data))) ("-" (link '(dec Data))) ("." (link '(prin (char (car Data))))) ("," (link '(set Data (char (read))))) ("[" (link '(setq Code ((if (=0 (car Data)) cdar cdr) Code) ) ) (push 'Stack (chain (cons))) ) ("]" (unless Stack (quit "Unbalanced ']'") ) (link '(setq Code ((if (n0 (car Data)) cdar cdr) Code) ) ) (let (There (pop 'Stack) Here (cons There)) (chain (set There Here)) ) ) ) ) ) ) ) (when Stack (quit "Unbalanced '['") ) ) )
(de execute ()
(let Data (cons 0 (cons)) # Create initial cell (for (Code "Program" Code) # Run program (eval (pop 'Code)) ) (while (cadr Data) # Find beginning of data (setq Data @) ) (filter prog Data '(T NIL .)) ) ) # Return data space</lang>
Output:
: (compile "hello.bf") -> NIL : (execute) Goodbye, World! -> (0 10 33 44 71 87 98 100 114 121)
Alternative solution
# This implements a BrainFuck *interpreter* similar to the "official" one. # It has 30000 unsigned 8-bit cells with wrapping, going off the bounds # of the memory results in an error. (de bf (Prg) (let (P Prg S NIL D (need 30000 0) Dp D F T ) (while P (case (car P) ("+" (if F (set Dp (% (inc (car Dp) 256))))) ("-" (if F (set Dp (% (dec (car Dp) 256))))) (">" (if F (setq Dp (cdr Dp)))) ("<" (if F (setq Dp (prior Dp D)))) ("." (if F (prin (char (car Dp))))) ("," (if F (set Dp (char (read))))) ("[" (push 'S (if F (prior P Prg))) (setq F (n0 (car Dp))) ) ("]" (and (setq F (pop 'S)) (n0 (car Dp)) (setq P F) ) ) ) (pop 'P) ) ) ) # A little "Hello world! test of the interpreter." (bf (chop ">+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-] >++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++.------.--- -----.[-]>++++++++[<++++>- ]<+.[-]++++++++++." ) ) (bye)
PureBasic
Python
Ruby
Standard ML
Implementation in Standard ML.
TI-83 BASIC
Implementation in TI-83 BASIC.
TI-89 BASIC
Implementation in TI-89 Basic.
Tcl
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- PHP examples needing attention
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- TI-83 BASIC
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