1 // A Transpiler for the Brainf*** language |
|
2 //========================================= |
|
3 |
|
4 import io.Source |
|
5 import scala.util._ |
|
6 |
|
7 |
|
8 // loding a bf-file |
|
9 def load_bff(name: String) : String = |
|
10 Try(Source.fromFile(name)("ISO-8859-1").mkString).getOrElse("") |
|
11 |
|
12 // "splicing" a BF program counting occurrences |
|
13 def splice(cs: List[Char], acc: List[(Char, Int)]) : List[(Char, Int)] = (cs, acc) match { |
|
14 case (Nil, acc) => acc |
|
15 case (c :: cs, Nil) => splice(cs, List((c, 1))) |
|
16 case (c :: cs, (d, n) :: acc) => |
|
17 if (c == d) splice(cs, (c, n + 1) :: acc) |
|
18 else splice(cs, (c, 1) :: (d, n) :: acc) |
|
19 } |
|
20 |
|
21 def spl(s: String) = splice(s.toList, Nil).reverse |
|
22 |
|
23 // generating "compound" c-instructions |
|
24 def instr2(c: Char, n: Int) : String = c match { |
|
25 case '>' => "ptr += " + n.toString + ";" |
|
26 case '<' => "ptr -= " + n.toString + ";" |
|
27 case '+' => "(*ptr) += " + n.toString + ";" |
|
28 case '-' => "(*ptr) -= " + n.toString + ";" |
|
29 case '.' => "putchar(*ptr);" * n |
|
30 case ',' => "*ptr = getchar();\n" * n |
|
31 case '[' => "while(*ptr){" * n |
|
32 case ']' => "}" * n |
|
33 case _ => "" |
|
34 } |
|
35 |
|
36 |
|
37 def instrs2(prog: String) : String = |
|
38 spl(prog).map{ case (c, n) => instr2(c, n) }.mkString |
|
39 |
|
40 |
|
41 def compile_str(prog: String) : String = { |
|
42 "#include <string.h>\n" ++ |
|
43 "#include <stdio.h>\n" ++ |
|
44 "char field[30000];\n" ++ |
|
45 "char *ptr = &field[15000];" ++ |
|
46 "int main()\n{\n" ++ |
|
47 "memset(field, '\\0', 30000);\n" ++ |
|
48 instrs2(prog) ++ |
|
49 "\n return 0;\n}" |
|
50 } |
|
51 |
|
52 def compile(name: String, prog: String) = { |
|
53 val fw = new java.io.FileWriter(name + ".c") |
|
54 val is = compile_str(prog) |
|
55 //println(is) |
|
56 fw.write(is) |
|
57 fw.close() |
|
58 } |
|
59 |
|
60 import sys.process._ |
|
61 |
|
62 def compile_run(prog: String) = { |
|
63 compile("tmp", prog) |
|
64 "gcc -O0 -o tmp tmp.c".! |
|
65 "./tmp".! |
|
66 () |
|
67 } |
|
68 |
|
69 def time_needed[T](n: Int, code: => T) = { |
|
70 val start = System.nanoTime() |
|
71 for (i <- 0 until n) code |
|
72 val end = System.nanoTime() |
|
73 (end - start) / (n * 1.0e9) |
|
74 } |
|
75 |
|
76 // the mandelbrot program |
|
77 val b0 = load_bff("mandelbrot.bf") |
|
78 |
|
79 println(s"${time_needed(1, compile_run(b0))} secs") |
|
80 |
|
81 |
|
82 |
|
83 // a benchmark program (counts down from 'Z' to 'A') |
|
84 val b1 = """>++[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++ |
|
85 [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++ |
|
86 ++++++++[>++++++++++[>++++++++++[>++++++++++[>+ |
|
87 +++++++++[-]<-]<-]<-]<-]<-]<-]<-]++++++++++.""" |
|
88 |
|
89 println(s"${time_needed(1, compile_run(b1))} secs") |
|
90 |
|
91 |
|