diff -r 4de31fdc0d67 -r b5b6ed38c2f2 main_testing5/bf.scala --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main_testing5/bf.scala Mon Nov 02 13:10:02 2020 +0000 @@ -0,0 +1,227 @@ +// Core Part about an Interpreter for +// the Brainf***++ language +//============================================== + +object CW10a { + + +// representation of Bf memory + +type Mem = Map[Int, Int] + + +// (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. + +import io.Source +import scala.util._ + +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 ',' => (pc + 1, mp, write(mem, mp, scala.io.StdIn.readByte())) + 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) + + // new commands + case '@' => (pc + 1, mp, write(mem, sread(mem, mp), sread(mem, mp - 1))) + case '*' => (pc + 1, mp, write(mem, mp, sread(mem, mp) * sread(mem, mp -1))) + case '#' => { println(s"${sread(mem, mp)}"); (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/bf++-programs collected from the Internet +//========================================================== + + +// some contrived (small) programs +//--------------------------------- + +// clears the 0-cell +//run("[-]", Map(0 -> 100)) // Map will be 0 -> 0 + +// moves 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)) // Map(0 -> 0, 2 -> 42, 4 -> 42) + + +// prints out numbers 0 to 9 +//run("""+++++[->++++++++++<]>--<+++[->>++++++++++<<]>>++<<----------[+>.>.<+<]""") + +// bf++ program calculating the cube-function, 10 * 10 * 10 = 1000 +//run("""++++++++++#>+***#""") // Map(0 -> 10, 1 -> 1000) + + +// bf++ program copies 3 from 0-cell to to cells 1, 4, 5, 6 and 7 +// (note that because of how the program wprks cell 1 will contain 7) +//run("""+++>+@+@+@+@+@""") // Map(0 -> 3, 1 -> 7, 4 -> 3, 5 -> 3, 6 -> 3, 7 -> 3) + + + +// some more "useful" programs +//----------------------------- + +// hello world program 1 +//run("""++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++ +// ..+++.>>.<-.<.+++.------.--------.>>+.>++.""") + +// hello world program 2 +//run("""++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>+ +// +.<<+++++++++++++++.>.+++.------.--------.>+.>.""") + +// hello world program 3 +//run("""+++++++++[>++++++++>+++++++++++>+++++<<<-]>.>++.+++++++.. +// +++.>-.------------.<++++++++.--------.+++.------.--------.>+.""") + + +// draws the Sierpinski triangle +//run(load_bff("sierpinski.bf")) + + +//fibonacci numbers below 100 +//run("""+++++++++++ +// >+>>>>++++++++++++++++++++++++++++++++++++++++++++ +// >++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+> +// +<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[- +// <-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<< +// -]>>[-]]<<]>>>[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]] +// >[<<+>>[-]]<<<<<<<]>>>>>[+++++++++++++++++++++++++ +// +++++++++++++++++++++++.[-]]++++++++++<[->-<]>++++ +// ++++++++++++++++++++++++++++++++++++++++++++.[-]<< +// <<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<< +// [-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]""") + +//outputs the square numbers up to 10000 +//run("""++++[>+++++<-]>[<+++++>-]+<+[>[>+>+<<-]++>>[<<+>>-]>>>[-]++>[-]+ +// >>>+[[-]++++++>>>]<<<[[<++++++++<++>>-]+<.<[>----<-]<] +// <<[>>>>>[>>>[-]+++++++++<[>-<-]+++++++++>[-[<->-]+[<<<]]<[>+<-]>]<<-]<<-]""") + + +// calculates 2 to the power of 6 +//(example from a C-to-BF compiler at https://github.com/elikaski/BF-it) +//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') +// +//run(load_bff("benchmark.bf")) + +// calculates the Collatz series for numbers from 1 to 30 +// +//run(load_bff("collatz.bf")) + +}