brainfsck.c

// BrainFsck Ruby Extension by Keiya CHINEN <[email protected]>
// C extension and Ruby src was written by Keiya CHINEN <[email protected]>
// Original version (Pure-C): https://github.com/keiya/brainfuck

#include "ruby.h"
#include <stdio.h>
#include <stdlib.h>

char *prog;
int ary[30000];
int *ptr = ary;
int idx;

int stack[100];
int stack_flag[100];
int stack_idx = 0;

void brainfsck();

void
init()
{
    int i;
    for (i=0;i<100;i++) {
        stack[i] = 0;
        stack_flag[i] = 0;
    }
}

void
push(int val,int flag)
{
    if (stack_idx < 100) {
        stack[stack_idx++] = val;
        stack_flag[stack_idx] = flag;
    }
    else {
        fprintf(stderr,"stack overflow");
        exit(EXIT_FAILURE);
    }
}

int
pop()
{
    if (stack_idx > 0) {
        int tmp = stack[--stack_idx];
        return tmp;
    }
    else {
        fprintf(stderr,"stack underflow");
        exit(EXIT_FAILURE);
    }
}

int
check()
{
    int i;
    return stack_flag[stack_idx];
}

int
interpret(int startidx)
{
    int ch = prog[idx];
    switch (ch) {
        case '>':
            idx++;
            if (check()) break;
            ptr++;
            break;
        case '<':
            idx++;
            if (check()) break;
            ptr--;
            break;
        case '+':
            idx++;
            if (check()) break;
            (*ptr)++;
            break;
        case '-':
            idx++;
            if (check()) break;
            (*ptr)--;
            break;
        case '.':
            idx++;
            if (check()) break;
            //putchar(*ptr);
            rb_funcall(rb_mKernel, rb_intern("print"),1, rb_str_new_cstr(ptr));
            fflush(stdout);
            break;
        case ',':
            idx++;
            if (check()) break;
            //*ptr = getchar();
            VALUE str = rb_funcall(rb_stdin, rb_intern("getc"),0);
            strncpy(ptr, StringValueCStr(str), 1);
            //*ptr = StringValueCStr(str);
            break;
        case '[':
            if (*ptr == 0) {
                push(idx,1);
                idx++;
            }
            else {
                push(idx,0);
                idx++;
            }
            break;
        case ']':
            if (check() != 1) {
                idx = pop();
            }
            else {
                pop();
                idx++;
            }
            break;
        case '\0':
            return 0;
        default:
            idx++;
            break;
    }
    return 1;
}


VALUE exec(VALUE self, VALUE bf)
{
   char *str = StringValueCStr(bf);
  init();
  unsigned long sz = strlen(str);

    int i;
    for (i=0; i<30000; i++)
        ary[i] = 0;

    if (NULL == (prog = (char *)malloc(sz))) {
        fprintf(stdout,"malloc\n");
        exit(EXIT_FAILURE);
    }
    strcpy(prog,str);

    fflush(stdin);

    idx = 0;
    while(interpret(0)) {
    
    }


  return Qnil;
}

void Init_brainfsck(void){
  VALUE rb_cBf;

  rb_cBf = rb_define_class("BrainFsck", rb_cObject);

  rb_define_method(rb_cBf, "exec", exec, 1);
}

brainfsck.rb

# BrainFsck

# C extension and Ruby src was written by Keiya CHINEN <[email protected]>
# brainf*ck test code by http://www.kmonos.net/alang/etc/brainfuck.php

require_relative "brainfsck.bundle"

bf = BrainFsck.new

# Hello World!
d = bf.exec(">+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-]<.>+++++++++++[<+++++>-]<.>++++++++[<+++>-]<.+++.------.--------.[-]>++++++++[<++++>-]<+.[-]++++++++++.")
puts()

# Hoge
bf.exec("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.+++++++.--------.--.")
puts()

# Hoge (uses loop)
bf.exec("++++++++++[>++++++++++<-]>++++.+++++++.--------.--.");
puts()

# Hello World! (alternative way)
bf.exec("++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.")
puts()

# Multiply
puts("4*2=")
bf.exec("++++>++><<[-  >[->>+<<]  >>[-<+<+>>]  <<<]>>++++++++++++++++++++++++++++++++++++++++++++++++.")
puts()

# conditional test (uppercase to lowercase)
puts("Upper Case to Lower Case. please input :")
bf.exec(<<-eos
### init: ##################################

>>++++++++[->++++++++<]>      # {3} = 0x40
>>>+++++++++[->++++++++++<]>  # {7} = 0x5A   ptr=7

### main: ##################################

[<<,                # {5} = getchar()

 ## 00 00 00 40 00 *ch 00 5A 00 00 00
  [->+<<+<<+>>>]    # {2:4:6} = !{5}
  <<<[->>>+<<<]>>>  # {5}     = !{2}
 ## 00 00 00 40 ch *ch ch 5A 00 00 00


  >>[->+>>+<<<]>    # {8:10}  = !{7}
 ## 00 00 00 40 ch ch ch 00 *5A 00 5A
  [                 # while( {8} ) do
    <<[->+>>+<<<]>> #   {7:9} = !{6}
    >[-<<<+>>>]<    #   {6}   = !{9}
    <[[-]<->]>      #   if({7}) then decr{6}
    -               #   decr {8}
  ]                 # end
  >>[-<<<+>>>]<<<<< # {7} = !{10}
 ## 00 00 00 40 ch *ch ans1 5A 00 00 00
 ##   ans1 = 0   iff   input le 5A


  <<[-<+<<+>>>]<    # {0:2}  = !{3}
 ## 40 00 *40 00 ch ch ans1 5A 00 00 00
  [                 # while( {2} ) do
    >>[-<+<<+>>>]<< #   {1:3} = !{4}
    <[->>>+<<<]>    #   {4}   = !{1}
    >[[-]>-<]<      #   if({3}) then decr{4}
    -               #   decr {2}
  ]                 # end
  <<[->>>+<<<]>>>>> # {3} = !{0}
 ## 00 00 00 40 ans2 *ch ans1 5A 00 00 00
 ##   ans2 = 0   iff   input le 40


 # if(ans2) if(not ans1) {5} add 0x20
  <[[-]                                  # if( {4} ) then do
    >++++++++++++++++++++++++++++++++    #   {5} add 0x20
    >[[-]                                #   if( !{6} ) then do
      <--------------------------------> #     {5} sub 0x20
    ]<<                                  #   end
  ]>>[-]<                                # end; !{6}

 ## 00 00 00 40 00 *ch 00 5A 00 00 00
.>>] # putchar {5}
eos
)

# echo (gets from STDIN => puts to STDOUT)
#bf.exec("+[>,.<]")

extconf.rb

require 'mkmf'
create_makefile('brainfsck')