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 |
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13 // simple instructions |
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14 def instr(c: Char) : String = c match { |
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15 case '>' => "ptr++;" |
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16 case '<' => "ptr--;" |
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17 case '+' => "(*ptr)++;" |
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18 case '-' => "(*ptr)--;" |
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19 case '.' => "putchar(*ptr);" |
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20 case ',' => "*ptr = getchar();\n" |
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21 case '[' => "while(*ptr){" |
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22 case ']' => "}" |
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23 case _ => "" |
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24 } |
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25 |
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26 def instrs(prog: String) : String = |
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27 prog.toList.map(instr(_)).mkString |
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28 |
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29 |
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30 def compile_str(prog: String) : String = { |
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31 "#include <string.h>\n" ++ |
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32 "#include <stdio.h>\n" ++ |
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33 "char field[30000];\n" ++ |
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34 "char *ptr = &field[15000];" ++ |
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35 "int main()\n{\n" ++ |
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36 "memset(field, '\\0', 30000);\n" ++ |
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37 instrs(prog) ++ |
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38 "\n return 0;\n}" |
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39 } |
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40 |
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41 def compile(name: String, prog: String) = { |
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42 val fw = new java.io.FileWriter(name + ".c") |
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43 val is = compile_str(prog) |
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44 //println(is) |
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45 fw.write(is) |
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46 fw.close() |
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47 } |
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48 |
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49 // running the c-compiler over the transpiled |
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50 // BF program and running the result |
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51 import sys.process._ |
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52 |
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53 def compile_run(prog: String) = { |
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54 compile("tmp", prog) |
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55 "gcc -O3 -o tmp tmp.c".! |
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56 "./tmp".! |
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57 () |
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58 } |
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59 |
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60 def time_needed[T](n: Int, code: => T) = { |
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61 val start = System.nanoTime() |
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62 for (i <- 0 until n) code |
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63 val end = System.nanoTime() |
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64 (end - start)/(n * 1.0e9) |
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65 } |
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66 |
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67 // the mandelbrot program |
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68 val b0 = load_bff("mandelbrot.bf") |
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69 |
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70 println(s"${time_needed(1, compile_run(b0))} secs") |
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71 |
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72 |
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73 |
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74 // a benchmark program (counts down from 'Z' to 'A') |
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75 val b1 = """>++[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++ |
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76 [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++ |
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77 ++++++++[>++++++++++[>++++++++++[>++++++++++[>+ |
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78 +++++++++[-]<-]<-]<-]<-]<-]<-]<-]++++++++++.""" |
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79 |
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80 println(s"${time_needed(1, compile_run(b1))} secs") |
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81 |
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82 |
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83 |
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84 |
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