Execute Brain****

From Rosetta Code
Revision as of 20:44, 19 October 2011 by rosettacode>CRGreathouse (GP)
Task
Execute Brain****
You are encouraged to solve this task according to the task description, using any language you may know.
Execute Brain**** is an implementation of Brainf***. Other implementations of Brainf***.

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

Implementation in Algol 68.

Ada

Implementation in Ada.

AutoHotkey

Implementation in AutoHotkey.

BASIC

Implementation in BASIC (QuickBasic dialect).

Brat

Implementation in Brat

C

Implementation in C.

C#

Implementation in C#.

C++

Implementation in 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

Implementation in D.

dodo0

<lang python>#Import some functions clojure('count', 1) -> size clojure('nth', 2) -> charAt clojure('inc', 1) -> inc clojure('dec', 1) -> dec clojure('char', 1) -> char clojure('int', 1) -> int clojure('read-line', 0) -> readLine

  1. The characters we will need

charAt("\n", 0) -> newLine charAt("@", 0) -> exitCommand charAt("+", 0) -> incrCommand charAt("-", 0) -> decrCommand charAt("<", 0) -> shlCommand charAt(">", 0) -> shrCommand charAt(".", 0) -> printCommand charAt(",", 0) -> inputCommand charAt("[", 0) -> repeatCommand charAt("]", 0) -> endCommand

  1. Read a character from a line of input.

fun readChar -> return ( readLine() -> line size(line) -> length

#Return the ith character and a continuation fun nextFromLine -> i, return ( '='(i, length) -> eol if (eol) -> ( return(newLine, readChar) #end of line ) | charAt(line, i) -> value inc(i) -> i fun next (-> return) nextFromLine(i, return) | next return(value, next) ) | nextFromLine

nextFromLine(0, return) #first character (position 0) ) | readChar

  1. Define a buffer as a value and a left and right stack

fun empty (-> return, throw) throw("Error: out of bounds") | empty fun fill (-> return, throw) return(0, fill) | fill

fun makeBuffer -> value, left, right, return ( fun buffer (-> return) return(value, left, right) | buffer return(buffer) ) | makeBuffer

fun push -> value, stack, return ( fun newStack (-> return, throw) return(value, stack) | newStack return(newStack) ) | push

  1. Brainf*** operations

fun noop -> buffer, input, return ( return(buffer, input) ) | noop

fun selectOp -> command, return ( '='(command, incrCommand) -> eq if (eq) -> ( fun increment -> buffer, input, return ( buffer() -> value, left, right inc(value) -> value makeBuffer(value, left, right) -> buffer return(buffer, input) ) | increment return(increment) ) | '='(command, decrCommand) -> eq if (eq) -> ( fun decrement -> buffer, input, return ( buffer() -> value, left, right dec(value) -> value makeBuffer(value, left, right) -> buffer return(buffer, input) ) | decrement return(decrement) ) | '='(command, shlCommand) -> eq if (eq) -> ( fun shiftLeft -> buffer, input, return ( buffer() -> value, left, right push(value, right) -> right left() -> value, left ( makeBuffer(value, left, right) -> buffer return(buffer, input) ) | message println(message) -> exit() ) | shiftLeft return(shiftLeft) ) | '='(command, shrCommand) -> eq if (eq) -> ( fun shiftRight -> buffer, input, return ( buffer() -> value, left, right push(value, left) -> left right() -> value, right ( makeBuffer(value, left, right) -> buffer return(buffer, input) ) | message println(message) -> exit() ) | shiftRight return(shiftRight) ) | '='(command, printCommand) -> eq if (eq) -> ( fun putChar -> buffer, input, return ( buffer() -> value, left, right char(value) -> value 'print'(value) -> dummy 'flush'() -> dummy return(buffer, input) ) | putChar return(putChar) ) | '='(command, inputCommand) -> eq if (eq) -> ( fun getChar -> buffer, input, return ( input() -> letter, input int(letter) -> letter buffer() -> value, left, right makeBuffer(letter, left, right) -> buffer return(buffer, input) ) | getChar return(getChar) ) | return(noop) ) | selectOp

  1. Repeat until zero operation

fun whileLoop -> buffer, input, continue, break ( buffer() -> value, left, right '='(value, 0) -> zero if (zero) -> ( break(buffer, input) ) | continue(buffer, input) -> buffer, input whileLoop(buffer, input, continue, break) ) | whileLoop

  1. Convert the Brainf*** program into dodo0 instructions

fun compile -> input, endmark, return ( input() -> command, input

'='(command, endmark) -> eq if (eq) -> ( return(noop, input) #the end, stop compiling ) | #Put in sequence the current operation and the rest of the program fun chainOp -> op, input, return ( compile(input, endmark) -> program, input fun exec -> buffer, input, return ( op(buffer, input) -> buffer, input program(buffer, input, return) ) | exec return(exec, input) ) | chainOp

'='(command, repeatCommand) -> eq if (eq) -> ( compile(input, endCommand) -> body, input #compile until "]"

#Repeat the loop body until zero fun repeat -> buffer, input, return ( whileLoop(buffer, input, body, return) ) | repeat chainOp(repeat, input, return) ) | selectOp(command) -> op chainOp(op, input, return) ) | compile

  1. Main program

compile(readChar, exitCommand) -> program, input makeBuffer(0, empty, fill) -> buffer input() -> nl, input #consume newline from input

  1. Execute the program instructions

program(buffer, input) -> buffer, input exit()</lang> Execution: 

$ java -classpath antlr-3.2.jar:clojure-1.2.0/clojure.jar:. clojure.main dodo/runner.clj bfc2.do0 
++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.@
Hello World!

E

Implementation in E.

Erlang

Implementation in Erlang.

Forth

Implementation in Forth.

F#

Implementation in 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;

  1. An addition

Brainfuck("+++.<+++++.[->+<]>.");

  1. 3
  2. 5
  3. 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

Implementation in Haskell.

Icon and Unicon

Implementation in Icon/Unicon.

J

Implementation in J.

Java

Implementation in Java.

JavaScript

Implementation in JavaScript.

Lua

Implementation in Lua.

Modula-3

Implementation in 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)

  1. bf(hello_world)

</lang>

OCaml

Implementation in OCaml.

PARI/GP

A case statement would have been really useful here... <lang parigp>BF(prog)={ prog=Vec(Str(prog)); my(codeptr,ptr=1,v=vector(1000),t); while(codeptr++ <= #prog, t=prog[codeptr]; if(t=="+", v[ptr]++ , if(t=="-", v[ptr]-- , if(t==">", ptr++ , if(t=="<", ptr-- , if(t=="[" && !v[ptr], t=1; while(t, if(prog[codeptr++]=="[",t++); if(prog[codeptr]=="]",t--) ); ); if(t=="]"&&v[ptr], t=1; while(t, if(prog[codeptr--]=="[",t--); if(prog[codeptr]=="]",t++) ) ); if(t==".", print1(Strchr(v[ptr])) ); if(t==",", v[ptr]=Vecsmall(input)[1] ) ) ) ) ) ) };</lang>

Perl

Implementation in Perl.

Perl 6

Implementation in Perl 6.

PHP

This example may be incorrect.
Near-duplicate entries; gurus please check.
Please verify it and remove this message. If the example does not match the requirements or does not work, replace this message with Template:incorrect or fix the code yourself.

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

Implementation in PureBasic

Python

Implementation in Python.

Retro

Implementation in Retro.

Ruby

Implementation in Ruby.

Standard ML

Implementation in Standard ML.

TI-83 BASIC

Implementation in TI-83 BASIC.

TI-89 BASIC

Implementation in TI-89 Basic.

Tcl

Implementation in Tcl.

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