1 // A Transpiler for the Brainf*** language to C |
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2 //=============================================== |
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3 // |
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4 // Call with |
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5 // |
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6 // amm bfc0.sc <<bf_program.bf>> |
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7 // |
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8 |
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9 |
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10 import scala.util._ |
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11 |
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12 |
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13 // loding a bf-file |
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14 def load_bff(name: String) : String = |
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15 Try(Source.fromFile(name)("ISO-8859-1").mkString).getOrElse("") |
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16 |
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17 |
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18 // simple instructions |
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19 def instr(c: Char) : String = c match { |
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20 case '>' => "ptr++;" |
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21 case '<' => "ptr--;" |
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22 case '+' => "(*ptr)++;" |
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23 case '-' => "(*ptr)--;" |
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24 case '.' => "putchar(*ptr);" |
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25 case ',' => "*ptr = getchar();\n" |
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26 case '[' => "while(*ptr){" |
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27 case ']' => "}" |
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28 case _ => "" |
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29 } |
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30 |
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31 def instrs(prog: String) : String = |
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32 prog.toList.map(instr(_)).mkString |
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33 |
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34 |
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35 def compile_str(prog: String) : String = { |
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36 "#include <string.h>\n" ++ |
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37 "#include <stdio.h>\n" ++ |
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38 "char field[30000];\n" ++ |
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39 "char *ptr = &field[15000];" ++ |
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40 "int main()\n{\n" ++ |
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41 "memset(field, '\\0', 30000);\n" ++ |
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42 instrs(prog) ++ |
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43 "\n return 0;\n}" |
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44 } |
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45 |
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46 def compile(name: String, prog: String) = { |
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47 val fw = new java.io.FileWriter(name + ".c") |
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48 val is = compile_str(prog) |
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49 //println(is) |
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50 fw.write(is) |
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51 fw.close() |
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52 } |
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53 |
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54 // running the c-compiler over the transpiled |
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55 // BF program and running the result |
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56 import sys.process._ |
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57 |
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58 def compile_run(prog: String) = { |
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59 compile("tmp", prog) |
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60 "gcc -O3 -o tmp tmp.c".! |
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61 "./tmp".! |
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62 () |
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63 } |
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64 |
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65 def time_needed[T](n: Int, code: => T) = { |
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66 val start = System.nanoTime() |
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67 for (i <- 0 until n) code |
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68 val end = System.nanoTime() |
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69 (end - start)/(n * 1.0e9) |
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70 } |
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71 |
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72 // Running Testcases |
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73 //=================== |
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74 |
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75 @doc(" the argument should be a BF program ") |
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76 @main |
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77 def main(fname: String) = { |
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78 val bf_str = os.read(os.pwd / fname) |
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79 println(s"${time_needed(1, run(bf_str))} secs") |
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80 } |
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81 |
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82 |
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83 |
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