diff -r 19b75e899d37 -r 9c03b5e89a2a marking5/bf.scala --- a/marking5/bf.scala Fri Apr 26 17:29:30 2024 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,225 +0,0 @@ -// Part 1 about an Interpreter for the Brainf*** language -//======================================================== - -object CW10a { - - -type Mem = Map[Int, Int] - - -import io.Source -import scala.util._ - -// (1) Write a function that takes a file name as argument and -// and requests the corresponding file from disk. It Returns the -// content of the file as a String. If the file does not exists, -// the function should Return the empty string. - -def load_bff(name: String) : String = - Try(Source.fromFile(name)("ISO-8859-1").mkString).getOrElse("") - - -// (2) Complete the functions for safely reading -// and writing brainf*** memory. Safely read should -// Return the value stored in the Map for a given memory -// pointer, provided it exists; otherwise it Returns 0. The -// writing function generates a new Map with the -// same data, except at the given memory pointer the -// value v is stored. - - -def sread(mem: Mem, mp: Int) : Int = - mem.getOrElse(mp, 0) - -def write(mem: Mem, mp: Int, v: Int) : Mem = - mem.updated(mp, v) - - -// (3) Implement the two jumping instructions in the -// brainf*** language. In jumpRight, given a program and -// a program counter move the program counter to the right -// until after the *matching* ]-command. Similarly, -// jumpLeft implements the move to the left to just after -// the *matching* [-command. - -def jumpRight(prog: String, pc: Int, level: Int) : Int = { - if (prog.length <= pc) pc - else (prog(pc), level) match { - case (']', 0) => pc + 1 - case (']', l) => jumpRight(prog, pc + 1, l - 1) - case ('[', l) => jumpRight(prog, pc + 1, l + 1) - case (_, l) => jumpRight(prog, pc + 1, l) - } -} - -def jumpLeft(prog: String, pc: Int, level: Int) : Int = { - if (pc < 0) pc - else (prog(pc), level) match { - case ('[', 0) => pc + 1 - case ('[', l) => jumpLeft(prog, pc - 1, l - 1) - case (']', l) => jumpLeft(prog, pc - 1, l + 1) - case (_, l) => jumpLeft(prog, pc - 1, l) - } -} - -// test cases -//jumpRight("""--[..+>--],>,++""", 3, 0) // => 10 -//jumpLeft("""--[..+>--],>,++""", 8, 0) // => 3 -//jumpRight("""--[..[+>]--],>,++""", 3, 0) // => 12 -//jumpRight("""--[..[[-]+>[.]]--],>,++""", 3, 0) // => 18 -//jumpRight("""--[..[[-]+>[.]]--,>,++""", 3, 0) // => 22 (outside) -//jumpLeft("""[******]***""", 7, 0) // => -1 (outside) - -// (4) Complete the compute function that interprets (runs) a brainf*** -// program: the arguments are a program (represented as a string), a program -// counter, a memory counter and a brainf*** memory. It Returns the -// memory at the stage when the execution of the brainf*** program -// finishes. The interpretation finishes once the program counter -// pc is pointing to something outside the program string. -// If the pc points to a character inside the program, the pc, -// memory pointer and memory need to be updated according to -// rules of the brainf*** language. Then, recursively, the compute -// function continues with the command at the new program -// counter. -// Implement the run function that calls compute with the program -// counter and memory counter set to 0. - -def compute(prog: String, pc: Int, mp: Int, mem: Mem) : Mem = { - if (0 <= pc && pc < prog.length) { - val (new_pc, new_mp, new_mem) = prog(pc) match { - case '>' => (pc + 1, mp + 1, mem) - case '<' => (pc + 1, mp - 1, mem) - case '+' => (pc + 1, mp, write(mem, mp, sread(mem, mp) + 1)) - case '-' => (pc + 1, mp, write(mem, mp, sread(mem, mp) - 1)) - case '.' => { print(sread(mem, mp).toChar); (pc + 1, mp, mem) } - case ',' => (pc + 1, mp, write(mem, mp, Console.in.read().toByte)) - case '[' => - if (sread(mem, mp) == 0) (jumpRight(prog, pc + 1, 0), mp, mem) else (pc + 1, mp, mem) - case ']' => - if (sread(mem, mp) != 0) (jumpLeft(prog, pc - 1, 0), mp, mem) else (pc + 1, mp, mem) - case _ => (pc + 1, mp, mem) - } - compute(prog, new_pc, new_mp, new_mem) - } - else mem -} - -def run(prog: String, m: Mem = Map()) = compute(prog, 0, 0, m) - - -/* - -// some sample bf-programs collected from the Internet -//===================================================== - - -// first some contrived (small) programs - -// clears the 0-cell -run("[-]", Map(0 -> 100)) // Map will be 0 -> 0 - -// copies content of the 0-cell to 1-cell -run("[->+<]", Map(0 -> 10)) // Map will be 0 -> 0, 1 -> 10 - - -// copies content of the 0-cell to 2-cell and 4-cell -run("[>>+>>+<<<<-]", Map(0 -> 42)) - - -// prints out numbers 0 to 9 -run("""+++++[->++++++++++<]>--<+++[->>++++++++++<<]>>++<<----------[+>.>.<+<]""") - - -// some more "useful" programs - -// hello world program 1 -run("""++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++ - ..+++.>>.<-.<.+++.------.--------.>>+.>++.""") - -// hello world program 2 -run("""++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>+ - +.<<+++++++++++++++.>.+++.------.--------.>+.>.""") - - -// draws the Sierpinski triangle -run("""++++++++[>+>++++<<-]>++>>+<[-[>>+<<-]+>>]>+[-<<<[ - ->[+[-]+>++>>>-<<]<[<]>>++++++[<<+++++>>-]+<<++.[-]<< - ]>.>+[>>]>+]""") - -run(load_bff("sierpinski.bf")) - - -//fibonacci numbers below 100 -run("""+++++++++++ - >+>>>>++++++++++++++++++++++++++++++++++++++++++++ - >++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+> - +<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[- - <-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<< - -]>>[-]]<<]>>>[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]] - >[<<+>>[-]]<<<<<<<]>>>>>[+++++++++++++++++++++++++ - +++++++++++++++++++++++.[-]]++++++++++<[->-<]>++++ - ++++++++++++++++++++++++++++++++++++++++++++.[-]<< - <<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<< - [-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]""") - - -//outputs the square numbers up to 10000 -run("""++++[>+++++<-]>[<+++++>-]+<+[ - >[>+>+<<-]++>>[<<+>>-]>>>[-]++>[-]+ - >>>+[[-]++++++>>>]<<<[[<++++++++<++>>-]+<.<[>----<-]<] - <<[>>>>>[>>>[-]+++++++++<[>-<-]+++++++++>[-[<->-]+[<<<]]<[>+<-]>]<<-]<<-]""") - -//collatz numbers (needs a number to be typed in) -run(""">,[[----------[ - >>>[>>>>]+[[-]+<[->>>>++>>>>+[>>>>]++[->+<<<<<]]<<<] - ++++++[>------<-]>--[>>[->>>>]+>+[<<<<]>-],<]>]>>>++>+>>[ - <<[>>>>[-]+++++++++<[>-<-]+++++++++>[-[<->-]+[<<<<]]<[>+<-]>] - >[>[>>>>]+[[-]<[+[->>>>]>+<]>[<+>[<<<<]]+<<<<]>>>[->>>>]+>+[<<<<]] - >[[>+>>[<<<<+>>>>-]>]<<<<[-]>[-<<<<]]>>>>>>> - ]>>+[[-]++++++>>>>]<<<<[[<++++++++>-]<.[-]<[-]<[-]<]<,]""") - - -// infinite collatz (never stops) -run(""">>+>+<[[->>[>>]>>>[>>]+[<<]<<<[<<]>[>[>>]>>+>[>>]<+<[<<]<<<[< - <]>-]>[>>]>>[<<<<[<<]>+>[>>]>>-]<<<<[<<]+>>]<<[+++++[>+++++++ - +<-]>.<++++++[>--------<-]+<<]>>[>>]+[>>>>[<<+>+>-]<-[>+<-]+< - [<<->>-[<<+>>[-]]]>>>[<<<+<<+>>>>>-]<<<[>>>+<<<-]<<[[-]>+>>-> - [<+<[<<+>>-]<[>+<-]<[>+<-]>>>>-]<[>+<-]+<[->[>>]<<[->[<+++>-[ - <+++>-[<+++>-[<[-]++>>[-]+>+<<-[<+++>-[<+++>-[<[-]+>>>+<<-[<+ - ++>-[<+++>-]]]]]]]]]<[>+<-]+<<]>>>+<[->[<+>-[<+>-[<+>-[<+>-[< - +>-[<+>-[<+>-[<+>-[<+>-[<[-]>>[-]+>+<<-[<+>-]]]]]]]]]]]<[>+<- - ]+>>]<<[<<]>]<[->>[->+>]<[-[<+>-[<->>+<-[<+>-[<->>+<-[<+>-[<- - >>+<-[<+>-[<->>+<-[<+>-[<->>+<-[<+>-[<->>+<-[<+>-[<->>+<-[<+> - -[<->>+<-[<+>-[<->>+<-[<+>-]]]]]]]]]]]]]]]]]]]>[<+>-]<+<[<+++ - +++++++>-]<]>>[<+>->>]<<[>+>+<<-]>[<+>-]+>[<->[-]]<[-<<-]<<[< - <]]++++++[>+++++++<-]>++.------------.[-]>[>>]<<[+++++[>+++++ - +++<-]>.<++++++[>--------<-]+<<]+<]>[<+>-]<]>>>[>>]<<[>[-]<-< - <]++++++++++.[-]<<<[<<]>>>+<[->[<+>-[<+>-[<+>-[<+>-[<+>-[<+>- - [<+>-[<+>-[<+>-[<[-]>>[-]+>+<<-]]]]]]]]]]<[>+<-]+>>]<<[<<]>>]""") - - - -// a Mandelbrot set generator in brainf*** written by Erik Bosman -// (http://esoteric.sange.fi/brainfuck/utils/mandelbrot/) - -run(load_bff("mandelbrot.bf")) - - -// a benchmark program (counts down from 'Z' to 'A') -val b1 = """>++[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++ - [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++ - ++++++++[>++++++++++[>++++++++++[>++++++++++[>+ - +++++++++[-]<-]<-]<-]<-]<-]<-]<-]++++++++++.""" - - -def time_needed[T](n: Int, code: => T) = { - val start = System.nanoTime() - for (i <- 0 until n) code - val end = System.nanoTime() - (end - start)/(n * 1.0e9) -} - -time_needed(1, run(b1)) -*/ - -}