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1 // A Transpiler for the Brainf*** language |
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2 //========================================= |
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3 |
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4 import io.Source |
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5 import scala.util._ |
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6 |
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7 |
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8 // loding a bf-file |
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9 def load_bff(name: String) : String = |
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10 Try(Source.fromFile(name)("ISO-8859-1").mkString).getOrElse("") |
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11 |
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12 def splice(cs: List[Char], acc: List[(Char, Int)]) : List[(Char, Int)] = (cs, acc) match { |
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13 case (Nil, acc) => acc |
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14 case (c :: cs, Nil) => splice(cs, List((c, 1))) |
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15 case (c :: cs, (d, n) :: acc) => |
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16 if (c == d) splice(cs, (c, n + 1) :: acc) |
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17 else splice(cs, (c, 1) :: (d, n) :: acc) |
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18 } |
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19 |
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20 def spl(s: String) = splice(s.toList, Nil).reverse |
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21 |
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22 def instr2(c: Char, n: Int) : String = c match { |
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23 case '>' => "ptr += " + n.toString + ";" |
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24 case '<' => "ptr -= " + n.toString + ";" |
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25 case '+' => "(*ptr) += " + n.toString + ";" |
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26 case '-' => "(*ptr) -= " + n.toString + ";" |
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27 case '.' => "putchar(*ptr);" * n |
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28 case ',' => "*ptr = getchar();\n" * n |
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29 case '[' => "while(*ptr){" * n |
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30 case ']' => "}" * n |
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31 case _ => "" |
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32 } |
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33 |
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34 |
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35 def instrs2(prog: String) : String = |
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36 spl(prog).map{ case (c, n) => instr2(c, n) }.mkString |
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37 |
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38 |
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39 def compile_str(prog: String) : String = { |
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40 "#include <string.h>\n" ++ |
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41 "#include <stdio.h>\n" ++ |
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42 "char field[30000];\n" ++ |
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43 "char *ptr = &field[15000];" ++ |
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44 "int main()\n{\n" ++ |
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45 "memset(field, '\\0', 30000);\n" ++ |
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46 instrs2(prog) ++ |
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47 "\n return 0;\n}" |
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48 } |
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49 |
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50 def compile(name: String, prog: String) = { |
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51 val fw = new java.io.FileWriter(name + ".c") |
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52 val is = compile_str(prog) |
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53 //println(is) |
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54 fw.write(is) |
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55 fw.close() |
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56 } |
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57 |
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58 import sys.process._ |
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59 |
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60 def compile_run(prog: String) = { |
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61 compile("tmp", prog) |
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62 "gcc -O3 -o tmp tmp.c".! |
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63 "./tmp".! |
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64 () |
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65 } |
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66 |
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67 def time_needed[T](n: Int, code: => T) = { |
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68 val start = System.nanoTime() |
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69 for (i <- 0 until n) code |
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70 val end = System.nanoTime() |
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71 (end - start) / (n * 1.0e9) |
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72 } |
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73 |
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74 |
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75 println(s"${time_needed(1, compile_run(load_bff("mandelbrot.bf")))} secs") |
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76 |
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77 |
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78 |
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79 // a benchmark program (counts down from 'Z' to 'A') |
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80 val b1 = """>++[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++ |
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81 [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++ |
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82 ++++++++[>++++++++++[>++++++++++[>++++++++++[>+ |
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83 +++++++++[-]<-]<-]<-]<-]<-]<-]<-]++++++++++.""" |
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84 |
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85 println(s"${time_needed(1, compile_run(b1))} secs") |