diff -r 31a9f89776a3 -r d47041b23498 progs/while-compiler-arrays/compile_bfc.sc
--- a/progs/while-compiler-arrays/compile_bfc.sc	Mon Oct 26 10:24:59 2020 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,310 +0,0 @@
-// Some more interesting testcases for the 
-// WHILE compiler with arrays, it includes: 
-//
-//  - a small parser for WHILE programs
-//
-//  - transpiles BF programs into WHILE programs
-//    and then compiles and runs them
-//
-//  - the power-example is the Mandelbrot set:
-//       
-//       * 65k for the transpiled WHILE program 
-//       * parsing uses around 30 secs using fastparse
-//       * the jasmin assembly file is 236k
-//       * the resulting Java program takes about 20 secs 
-//
-// Call with (X being 0,1,..,4)
-//
-//  amm compile_bfc.sc all
-//  amm compile_bfc.sc bfcX
-
-
-// load the compiler
-import $file.compile_arrays
-import compile_arrays._ 
-
-def time_needed[T](i: Int, code: => T) = {
-  val start = System.nanoTime()
-  for (j <- 2 to i) code
-  val result = code
-  val end = System.nanoTime()
-  ((end - start) / (i * 1.0e9), result)
-}
-
-// for BF we have to change the write library-function,
-// because in BF integers are written out as characters
-val beginning = """
-.class public XXX.XXX
-.super java/lang/Object
-
-.method public static write(I)V 
-    .limit locals 1 
-    .limit stack 2 
-    getstatic java/lang/System/out Ljava/io/PrintStream; 
-    iload 0
-    i2c                                           ; Int => Char
-    invokevirtual java/io/PrintStream/print(C)V   ; println(I)V => print(C)V    
-    return 
-.end method
-
-.method public static main([Ljava/lang/String;)V
-   .limit locals 200
-   .limit stack 200
-
-; COMPILED CODE STARTS   
-
-"""
-
-
-// modified main compilation function for blocks
-def compile(bl: Block, class_name: String) : String = {
-  val instructions = compile_block(bl, Map())._1
-  (beginning ++ instructions ++ ending).replace("XXX", class_name)
-}
-
-// automating the above
-import ammonite.ops._
-
-def compile_to_file(bl: Block, class_name: String) : Unit = 
-  write.over(pwd / s"$class_name.j", compile(bl, class_name))  
-
-def compile_and_run(bl: Block, class_name: String) : Unit = {
-  println(s"Start of compilation")
-  compile_to_file(bl, class_name)
-  println(s"generated $class_name.j file")
-  val (jasmin_time, _) = 
-    time_needed(1, os.proc("java", "-jar", "jasmin.jar", s"$class_name.j").call())
-  println(s"generated $class_name.class file (in $jasmin_time secs).")
-  val (running_time, output) = 
-    time_needed(1, os.proc("java", s"${class_name}/${class_name}").call().out.text())
-  println(output)
-  println(s"done (in $running_time secs).")
-}
-
-
-//=====================================
-// Grammar Rules for WHILE with arrays
-//=====================================
-
-import fastparse._
-import MultiLineWhitespace._
-
-def lowercase [_ : P] = P( CharIn("a-z") )
-def uppercase[_ : P]  = P( CharIn("A-Z") )
-def letter[_ : P]     = P( lowercase | uppercase )
-def digit [_ : P]     = P( CharIn("0-9") )
-
-def Number[_ : P]: P[Int] =  P( digit.rep(1) ).!.map(_.toInt)
-def Ident[_ : P]: P[String] = P( letter ~ (letter | digit | "_").rep ).!
-
-// arithmetic expressions
-def AExp[_ : P]: P[AExp] = 
-  P(  P(Te ~ "+" ~ AExp).map{ case (l, r) => Aop("+", l, r)} 
-    | P(Te ~ "-" ~ AExp).map{ case (l, r) => Aop("-", l, r)}
-    | Te )
-def Te[_ : P]: P[AExp] = 
-  P(  P(Fa ~ "*" ~ Te).map{ case (l, r) => Aop("*", l, r)} 
-    | Fa )   
-def Fa[_ : P]: P[AExp] = 
-  P( "(" ~ AExp ~ ")" 
-     | P (Ident ~ "[" ~ AExp ~ "]").map{Ref.tupled}
-     | P(Number).map{Num} 
-     | P(Ident).map{Var} )
-
-// boolean expressions
-def BExp[_ : P]: P[BExp] = 
-  P(  P(AExp ~ "=" ~ AExp).map{ case (x, z) => Bop("=", x, z)} 
-    | P(AExp ~ "!=" ~ AExp).map{ case (x, z) => Bop("!=", x, z)}  
-    | P(AExp ~ "<" ~ AExp).map{ case (x, z) => Bop("<", x, z)}  
-    | P(AExp ~ ">" ~ AExp).map{ case (x, z) => Bop("<", z, x)}  
-    | P("true").map{ _ => True} 
-    | P("false").map{ _ => False} 
-    | "(" ~ BExp ~ ")" )
-
-// statements and blocks
-def Stmt[_ : P]: P[Stmt] =
-  P(  P("skip").map( _ => Skip) 
-    | P(Ident ~ ":=" ~ AExp).map{Assign.tupled} 
-    | P(Ident ~ "[" ~ AExp ~ "]" ~ ":=" ~ AExp).map{AssignA.tupled} 
-    | P("if" ~ BExp ~ "then" ~ Block ~ "else" ~ Block).map{If.tupled} 
-    | P("while" ~ BExp ~ "do" ~ Block).map{While.tupled} 
-    | P("new(" ~ Ident ~ "[" ~ Number ~ "])").map{ArrayDef.tupled} 
-    | P("write(" ~ Ident ~ ")").map{Write} ) 
-
-def Stmts[_ : P]: P[Block] =
-  P(  P(Stmt ~ ";" ~ Stmts).map{ case (x, z) => x :: z } 
-    | P(Stmt).map{s => List(s)} ) 
-
-def Block[_ : P]: P[Block] =
-  P(  "{" ~ Stmts ~ "}" 
-    | P(Stmt).map(s => List(s)) )
-
-// some test cases for the parser
-
-//println(fastparse.parse("(1 + (2 + 5)) + 4", AExp(_)).get)
-//println(fastparse.parse("1 + 2 + 3 + 45", AExp(_)))
-//println(fastparse.parse("1 + 2 * 3", AExp(_)))
-//println(fastparse.parse("x + 2 * 3", AExp(_)))
-//println(fastparse.parse("x2 := 5 + a", Stmts(_)))
-//println(fastparse.parse("x2 := 5 + a[3+a]", Stmts(_)))
-//println(fastparse.parse("a[x2+3] := 5 + a[3+a]", Stmts(_)))
-//println(fastparse.parse("{x := 5; y := 8}", Block(_)))
-//println(fastparse.parse("if (false) then {x := 5} else {x := 10}", Block(_)))
-
-val fib = 
- """n := 10;
-    minus1 := 0;
-    minus2 := 1;
-    temp:=0;
-    while (n > 0) do {
-      temp := minus2; 
-      minus2 := minus1 + minus2;
-      minus1 := temp;
-      n := n - 1};
-    result := minus2;
-    write(result)
-   """
-
-//println(fastparse.parse(fib, Stmts(_)).get.value)
-
-
-
-//======================================
-// BF transpiler into WHILE with arrays
-//======================================
-
-// simple BF instructions translation
-def instr(c: Char) : String = c match {
-  case '>' => "ptr := ptr + 1;"
-  case '<' => "ptr := ptr - 1;"
-  case '+' => "mem[ptr] := mem[ptr] + 1;"
-  case '-' => "mem[ptr] := mem[ptr] - 1;"
-  case '.' => "x := mem[ptr]; write x;"
-  //case ',' => "XXX" // "ptr = getchar();\n"
-  case '['  => "while (mem[ptr] != 0) do {"
-  case ']'  => "skip};"
-  case _ => ""
-}
-
-def instrs(prog: String) : String =
-  prog.toList.map(instr).mkString
-
-
-// Note: Unfortunately, the transpiled mandelbrot.bf program 
-// is so large that it does not fit inside the limitations of 
-// what the JVM imposes on methods (only 64K of instructions).
-// Therefore some optimisations are first applied to 
-// BF programs before WHILE programs are created. The
-// optimisations are 
-//  
-//  - replacing BF-loops of the form [-] with a new 0-instruction 
-//  - combining single increment/decrement instructions
-//
-// The size of the resulting .j-file is 270K.
-
-
-def splice(cs: List[Char], acc: List[(Char, Int)]) : List[(Char, Int)] = (cs, acc) match {
-  case (Nil, acc) => acc
-  case (c :: cs, Nil) => splice(cs, List((c, 1)))
-  case (c :: cs, (d, n) :: acc) => 
-    if (c == d) splice(cs, (c, n + 1) :: acc)
-    else splice(cs, (c, 1) :: (d, n) :: acc)
-}
-
-def spl(s: String) = splice(s.toList, Nil).reverse
-
-def instr2(c: Char, n: Int) : String = c match {
-  case '>' => s"ptr := ptr + $n;"
-  case '<' => s"ptr := ptr - $n;"
-  case '0' => s"mem[ptr] := 0;"
-  case '+' => s"mem[ptr] := mem[ptr] + $n;"
-  case '-' => s"mem[ptr] := mem[ptr] - $n;"
-  case '.' => s"x := mem[ptr]; write(x);" 
-  case '['  => "while (mem[ptr] != 0) do {" * n 
-  case ']'  => "skip};" * n
-  case _ => ""
-}
-
-def instrs2(prog: String) : String =
-  spl(prog.replaceAll("""\[-\]""", "0")).map{ case (c, n) => instr2(c, n) }.mkString
-
-// adding the "header" to the BF program
-def bf_str(prog: String) : String = {
-  "new(mem[30000]);" ++
-  "ptr := 15000;" ++
-  instrs2(prog) ++
-  "skip"
-}
-
-
-def bf_run(prog: String, name: String) = {
-  println(s"BF pre-processing of $name")
-  val bf_string = bf_str(prog)
-  println(s"BF parsing (program length ${bf_string.length} characters)")
-  val (time, bf_prog) = 
-    time_needed(1, fastparse.parse(bf_string, Stmts(_)).get.value)
-  println(s"BF generated WHILE program (needed $time secs for parsing)")
-  compile_and_run(bf_prog, name)
-}
-
-// a benchmark program (counts down from 'Z' to 'A')
-@doc(" Benchmark 'Z' to 'A'.")
-@main
-def bfc0() = bf_run(read(pwd / "benchmark.bf"), "bench")
-
-
-@doc(" Sierpinski triangle.")
-@main
-def bfc1() = bf_run(read(pwd / "sierpinski.bf"), "sier")
-
-// Hello World
-val bf2 = """++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]
-      >>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++."""
-
-@doc(" Hello world.")
-@main
-def bfc2() = bf_run(bf2, "hello")
-
-// Fibonacci 
-val bf3 = """+++++++++++
-      >+>>>>++++++++++++++++++++++++++++++++++++++++++++
-      >++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+>
-      +<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[-
-      <-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<<
-      -]>>[-]]<<]>>>[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]
-      >[<<+>>[-]]<<<<<<<]>>>>>[+++++++++++++++++++++++++
-      +++++++++++++++++++++++.[-]]++++++++++<[->-<]>++++
-      ++++++++++++++++++++++++++++++++++++++++++++.[-]<<
-      <<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<<
-      [-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]
-      [-]++++++++++."""
-
-@doc(" Fibonacci numbers.")
-@main
-def bfc3() = bf_run(bf3, "fibs")
-
-// Mandelbrot Set
-//----------------
-//
-// Note: Parsing of the generated WHILE program (around 60K in size)
-// takes approximately 10 minutes to parse with our parser combinators,
-// and approximately 30 seconds with Ammonite's fastparse.
-
-@doc(" Mandelbrot set.")
-@main
-def bfc4() = bf_run(read(pwd / "mandelbrot.bf"), "mandelbrot")
-
-
-// this unfortunately hits the capacity of the JVM, even with optimisations
-//@doc(" Coolatz serries up to 30.")
-//@main
-//def bfc5() = bf_run(read(pwd / "collatz.bf"), "coll")
-
-
-//
-@doc(" All benchmarks.")
-@main
-def all() = { bfc0(); bfc1(); bfc2(); bfc3(); bfc4() } 
-
-
-