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February 14, 2018 17:58
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Attempt at writing brainfuck compiler in php
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<?php | |
function compile(string $brainfuck, $debug = false): array | |
{ | |
$program = []; | |
$pointer = 0; | |
$ip = 0; | |
$prog_length = strlen($brainfuck); | |
$loopStack = []; | |
while (true) { | |
$instr = $brainfuck[$ip]; | |
$ip_move = true; | |
switch ($instr) { | |
case '>': | |
$pointer++; | |
$debug && print ("\n[INF] Increment Data Pointer to: " . $pointer); | |
break; | |
case '<': | |
$pointer--; | |
$debug && print ("\n[INF] Decrement Data Pointer to: " . $pointer); | |
break; | |
case '+': | |
$program[$pointer] = isset($program[$pointer]) ? $program[$pointer] + 1 : 1; | |
$debug && print ("\n[INF] Increment value in Data Pointer: " . $pointer . ". Value: " . $program[$pointer]); | |
break; | |
case '-': | |
$program[$pointer] = isset($program[$pointer]) ? $program[$pointer] - 1 : -1; | |
$debug && print ("\n[INF] Decrement value in Data Pointer: " . $pointer . ". Value: " . $program[$pointer]); | |
break; | |
case '.': | |
fputs(STDOUT, $program[$pointer]); | |
$debug && print ("\n[INF] Write current value to STDOUT. Current Value: " . $program[$pointer]); | |
break; | |
case ',': | |
$program[$pointer] = fgetc(STDIN); | |
$debug && print ("\n[INF] Got value from user: " . $program[$pointer]); | |
break; | |
case '[': | |
if (!isset($program[$pointer])) { | |
$program[$pointer] = 0; | |
} | |
$ip_move = $program[$pointer] != 0; | |
array_push($loopStack, $ip); | |
if (!$ip_move) { | |
$pos = strpos($brainfuck, ']', $ip); | |
$ip = $pos + 1; | |
$debug && print ("\n[INF][IP] Move Instruction pointer to " . $ip); | |
} | |
break; | |
case ']': | |
if (!isset($program[$pointer])) { | |
$program[$pointer] = 0; | |
} | |
$ip_move = $program[$pointer] == 0; | |
// pop last position of `]` | |
$pos = array_pop($loopStack); | |
if (!$ip_move) { | |
// push it back | |
array_push($loopStack, $pos); | |
$ip = $pos + 1; | |
$debug && print ("\n[INF][IP] Move Instruction pointer to " . $ip); | |
} | |
break; | |
} | |
if ($ip_move) { | |
$ip++; | |
$debug && print ("\n[INF][IP] Move Instruction pointer to " . $ip); | |
} | |
if ($ip >= $prog_length) break; | |
} | |
return $program; | |
} | |
var_dump(compile('+++>+++>++++')); | |
var_dump(compile('++>>[-]<<[->>+<<]')); | |
var_dump(compile('++[-]')); | |
?> |
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Need to test user input and output. But everything else works.