test/turing.go

   1 // $G $F.go && $L $F.$A && ./$A.out
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 package main
   8
   9 // brainfuck
  10
  11 func main() {
  12        var a [30000]byte;
  13        prog := "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.";
  14        p := 0;
  15        pc := 0;
  16        for {
  17                switch prog[pc] {
  18                        case '>':
  19                                p++;
  20                        case '<':
  21                                p--;
  22                        case '+':
  23                                a[p]++;
  24                        case '-':
  25                                a[p]--;
  26                        case '.':
  27                                print string(a[p]);
  28                        case '[':
  29                                if a[p] == 0 {
  30                                        for nest := 1; nest > 0; pc++ {
  31                                                if prog[pc+1] == ']' {
  32                                                        nest--;
  33                                                }
  34                                                if prog[pc+1] == '[' {
  35                                                        nest++;
  36                                                }
  37                                        }
  38                                }
  39                        case ']':
  40                                if a[p] != 0 {
  41                                        for nest := -1; nest < 0; pc-- {
  42                                                if prog[pc-1] == ']' {
  43                                                        nest--;
  44                                                }
  45                                                if prog[pc-1] == '[' {
  46                                                        nest++;
  47                                                }
  48                                        }
  49                                }
  50                        default:
  51                                return;
  52                }
  53                pc++;
  54        }
  55 }