--- a/main_templates5/bfc.scala Sat Oct 08 00:30:51 2022 +0100
+++ b/main_templates5/bfc.scala Tue Nov 01 15:03:48 2022 +0000
@@ -4,7 +4,6 @@
object M5b {
-
// !!! Copy any function you need from file bf.scala !!!
//
// If you need any auxiliary function, feel free to
@@ -34,43 +33,12 @@
import io.Source
import scala.util._
-
-// TASKS
-//=======
+// ADD YOUR CODE BELOW
+//======================
-// (5) Write a function jtable that precomputes the "jump
-// table" for a bf-program. This function takes a bf-program
-// as an argument and Returns a Map[Int, Int]. The
-// purpose of this map is to record the information about
-// pc positions where '[' or a ']' are stored. The information
-// is to which pc-position do we need to jump next?
-//
-// For example for the program
-//
-// "+++++[->++++++++++<]>--<+++[->>++++++++++<<]>>++<<----------[+>.>.<+<]"
-//
-// we obtain the map
-//
-// Map(69 -> 61, 5 -> 20, 60 -> 70, 27 -> 44, 43 -> 28, 19 -> 6)
-//
-// This states that for the '[' on position 5, we need to
-// jump to position 20, which is just after the corresponding ']'.
-// Similarly, for the ']' on position 19, we need to jump to
-// position 6, which is just after the '[' on position 5, and so
-// on. The idea is to not calculate this information each time
-// we hit a bracket, but just look up this information in the
-// jtable. You can use the jumpLeft and jumpRight functions
-// from Part 1 for calculating the jtable.
-//
-// Then adapt the compute and run functions from Part 1
-// in order to take advantage of the information stored in the jtable.
-// This means whenever jumpLeft and jumpRight was called previously,
-// you should immediately look up the jump address in the jtable.
-
-
+// (5)
def jtable(pg: String) : Map[Int, Int] = ???
-
// testcase
//
// jtable("""+++++[->++++++++++<]>--<+++[->>++++++++++<<]>>++<<----------[+>.>.<+<]""")
@@ -80,26 +48,13 @@
def compute2(pg: String, tb: Map[Int, Int], pc: Int, mp: Int, mem: Mem) : Mem = ???
def run2(pg: String, m: Mem = Map()) = ???
-
// testcases
// time_needed(1, run2(load_bff("benchmark.bf")))
// time_needed(1, run2(load_bff("sierpinski.bf")))
-// (6) Write a function optimise which deletes "dead code" (everything
-// that is not a bf-command) and also replaces substrings of the form
-// [-] by a new command 0. The idea is that the loop [-] just resets the
-// memory at the current location to 0. In the compute3 and run3 functions
-// below you implement this command by writing the number 0 to mem(mp),
-// that is write(mem, mp, 0).
-//
-// The easiest way to modify a string in this way is to use the regular
-// expression """[^<>+\-.\[\]]""", which recognises everything that is
-// not a bf-command and replace it by the empty string. Similarly the
-// regular expression """\[-\]""" finds all occurrences of [-] and
-// by using the Scala method .replaceAll you can replace it with the
-// string "0" standing for the new bf-command.
+// (6)
def optimise(s: String) : String = ???
@@ -117,37 +72,14 @@
-// (7) Write a function combine which replaces sequences
-// of repeated increment and decrement commands by appropriate
-// two-character commands. For example for sequences of +
-//
-// orig bf-cmds | replacement
-// ------------------------------
-// + | +A
-// ++ | +B
-// +++ | +C
-// |
-// ... |
-// |
-// +++....+++ | +Z
-// (where length = 26)
-//
-// Similar for the bf-command -, > and <. All other commands should
-// be unaffected by this change.
-//
-// Adapt the compute4 and run4 functions such that they can deal
-// appropriately with such two-character commands.
-
-
+// (7)
def combine(s: String) : String = ???
// testcase
// combine(load_bff("benchmark.bf"))
-
def compute4(pg: String, tb: Map[Int, Int], pc: Int, mp: Int, mem: Mem) : Mem = ???
-
// should call first optimise and then combine on the input string
//
def run4(pg: String, m: Mem = Map()) = ???