--- 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))
-*/
-
-}