updated draft
authorChristian Urban <christian.urban@kcl.ac.uk>
Sun, 17 Sep 2023 19:12:57 +0100
changeset 919 d16037caa8fd
parent 918 19a5d332cb49
child 920 bcff91cc274f
updated
cws/build.sc
cws/cw01.pdf
cws/cw02.pdf
cws/cw03.pdf
cws/cw04.pdf
cws/cw05.pdf
cws/upload
progs/matcher/re1.sc
progs/matcher/re2.sc
progs/matcher/re3.sc
progs/parser-combinators/comb1.sc
progs/parser-combinators/comb2.sc
--- a/cws/build.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/cws/build.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -1,10 +1,10 @@
 #!/usr/bin/env amm
 
 val files = Seq("cw01.tex",
-	         "cw02.tex",
-	         "cw03.tex",
-	         "cw04.tex",
-	         "cw05.tex")
+	        "cw02.tex",
+	        "cw03.tex",
+	        "cw04.tex",
+	        "cw05.tex")
 
 val pdf_files = files.map(s => s.stripSuffix("tex") ++ "pdf")
 
@@ -13,8 +13,8 @@
 def make() = {
   for (f <- files) {
     println(s"Processing $f ...")
-    os.proc("xelatex", f).call(stdout = os.Inherit, stdin = os.Inherit)
-    os.proc("xelatex", f).call(stdout = os.Inherit, stdin = os.Inherit)
+    os.proc("lualatex", f).call(stdout = os.Inherit, stdin = os.Inherit)
+    os.proc("lualatex", f).call(stdout = os.Inherit, stdin = os.Inherit)
   }
 }
 
Binary file cws/cw01.pdf has changed
Binary file cws/cw02.pdf has changed
Binary file cws/cw03.pdf has changed
Binary file cws/cw04.pdf has changed
Binary file cws/cw05.pdf has changed
--- a/cws/upload	Fri Sep 15 10:49:33 2023 +0100
+++ b/cws/upload	Sun Sep 17 19:12:57 2023 +0100
@@ -8,5 +8,10 @@
 done    
 
 
-scp $fls k1192855@bastion:public_html/cfl/cws/
+scp $fls k1192855@bastion:public_html/cfl/cws
+
 
+#hg commit -m "updated jars"
+
+# prevent PDF from being copied
+###gs -o output.pdf -dNoOutputFonts -sDEVICE=pdfwrite main_cw01.pdf 
--- a/progs/matcher/re1.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/progs/matcher/re1.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -1,6 +1,6 @@
 // A simple matcher for basic regular expressions
 //
-// Call the test cases with X = {1,2,3}
+// Call the testcases with X = {1,2,3}
 //
 //   amm re1.sc testX
 //
@@ -19,9 +19,9 @@
 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp  // sequence
 case class STAR(r: Rexp) extends Rexp            // star
 
+
 // nullable function: tests whether a regular 
-// expression can recognise the empty string
-  
+// expression can recognise the empty string  
 def nullable(r: Rexp) : Boolean = r match {
   case ZERO => false
   case ONE => true
@@ -54,13 +54,12 @@
   nullable(ders(s.toList, r))
 
 
+// some examples from the homework
 
 val r = SEQ(CHAR('b'), CHAR('c'))
 matcher(r, "ac")
 
-// some examples from the homework
-
-val r = STAR(ALT(SEQ(CHAR('a'), CHAR('b')), CHAR('b')))
+val r1 = STAR(ALT(SEQ(CHAR('a'), CHAR('b')), CHAR('b')))
 der('a', r)
 der('b', r)
 der('c', r)
@@ -71,6 +70,9 @@
 der('z', der('y', der('x', r2)))
 
 
+// Test Cases
+//============
+
 // the optional regular expression (one or zero times)
 def OPT(r: Rexp) = ALT(r, ONE)   // r + 1
 
@@ -81,10 +83,6 @@
   case n => SEQ(r, NTIMES(r, n - 1))
 }
 
-
-// Test Cases
-//============
-
 // the evil regular expression  (a?){n} a{n}
 def EVIL1(n: Int) = 
   SEQ(NTIMES(OPT(CHAR('a')), n), NTIMES(CHAR('a'), n))
--- a/progs/matcher/re2.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/progs/matcher/re2.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -1,6 +1,8 @@
-// A Version with an explicit n-times regular expression;
+// A Version of the matcher with an explicit 
+// n-times regular expression
+//
 // this keeps the size of the regular expression in the
-// EVIL1 test-case quite small
+// EVIL1 testcase small
 //
 // call the test cases with X = {1,2}
 //
@@ -31,7 +33,6 @@
   case NTIMES(r, n) => if (n == 0) true else nullable(r)
 }
 
-
 def der(c: Char, r: Rexp) : Rexp = r match {
   case ZERO => ZERO
   case ONE => ZERO
@@ -54,13 +55,13 @@
   nullable(ders(s.toList, r))
 
 
+// Test Cases
+
 // the optional regular expression: one or zero times
 // this regular expression is still defined in terms of ALT
 def OPT(r: Rexp) = ALT(r, ONE)
 
 
-// Test Cases
-
 // evil regular expressions
 def EVIL1(n: Int) = SEQ(NTIMES(OPT(CHAR('a')), n), NTIMES(CHAR('a'), n))
 val EVIL2 = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))
@@ -90,7 +91,7 @@
 def test2() = {
   println("Test (a*)* b")
 
-  for (i <- 0 to 30 by 2) {
+  for (i <- 0 to 22 by 2) {
     println(f"$i: ${time_needed(1, matcher(EVIL2, "a" * i))}%.5f")
   }
 }
--- a/progs/matcher/re3.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/progs/matcher/re3.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -1,4 +1,6 @@
-// A version with simplification of derivatives;
+// A version of the matcher with simplification 
+// of derivatives
+//
 // this keeps the regular expressions small, which
 // is good for the run-time
 // 
@@ -48,6 +50,7 @@
     if (i == 0) ZERO else SEQ(der(c, r), NTIMES(r, i - 1))
 }
 
+// simplification
 def simp(r: Rexp) : Rexp = r match {
   case ALT(r1, r2) => (simp(r1), simp(r2)) match {
     case (ZERO, r2s) => r2s
@@ -64,26 +67,23 @@
   case r => r
 }
 
-
-
 // the derivative w.r.t. a string (iterates der)
 def ders(s: List[Char], r: Rexp) : Rexp = s match {
   case Nil => r
   case c::s => ders(s, simp(der(c, r)))
 }
 
-
 // the main matcher function
 def matcher(r: Rexp, s: String) : Boolean = 
   nullable(ders(s.toList, r))
 
 
+// Test Cases
+//============
+
 // one or zero
 def OPT(r: Rexp) = ALT(r, ONE)
 
-
-// Test Cases
-
 // evil regular expressions: (a?){n} a{n}  and (a*)* b
 def EVIL1(n: Int) = SEQ(NTIMES(OPT(CHAR('a')), n), NTIMES(CHAR('a'), n))
 val EVIL2 = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))
--- a/progs/parser-combinators/comb1.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/progs/parser-combinators/comb1.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -89,12 +89,12 @@
 extension [I, T](p: Parser[I, T])(using I => Seq[_]) {
   def ||(q : => Parser[I, T]) = new AltParser[I, T](p, q)
   def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-  def mapp[S](f: => T => S) = new MapParser[I, T, S](p, f)
+  def map[S](f: => T => S) = new MapParser[I, T, S](p, f)
 }
 
 def toU(s: String) = s.map(_.toUpper)
 
-(p"ELSE").mapp(toU(_)).parse("ELSEifthen")  
+(p"ELSE").map(toU(_)).parse("ELSEifthen")  
 
 // these implicits allow us to use an infix notation for
 // sequences and alternatives; we also can write the usual
@@ -109,8 +109,8 @@
 
 // A parser for palindromes (just returns them as string)
 lazy val Pal : Parser[String, String] = {
-   (p"a" ~ Pal ~ p"a").mapp{ case ((x, y), z) => s"$x$y$z" } || 
-   (p"b" ~ Pal ~ p"b").mapp{ case ((x, y), z) => s"$x$y$z" } || 
+   (p"a" ~ Pal ~ p"a").map{ case ((x, y), z) => s"$x$y$z" } || 
+   (p"b" ~ Pal ~ p"b").map{ case ((x, y), z) => s"$x$y$z" } || 
     p"a" || p"b" || p""
 }  
 
@@ -126,7 +126,7 @@
 //
 //   (transforms '(' -> '{' , ')' -> '}' )
 lazy val P : Parser[String, String] = {
-  (p"(" ~ P ~ p")" ~ P).mapp{ case (((_, x), _), y) => "{" + x + "}" + y } ||
+  (p"(" ~ P ~ p")" ~ P).map{ case (((_, x), _), y) => "{" + x + "}" + y } ||
   p""
 }  
 
@@ -224,32 +224,32 @@
 // a problem with the arithmetic expression parser: it 
 // gets very slow with deeply nested parentheses
 
-println("Runtime problem")
+println("A runtime problem")
 println(E.parse("1"))
 println(E.parse("(1)"))
 println(E.parse("((1))"))
 println(E.parse("(((1)))"))
 println(E.parse("((((1))))"))
-//println(E.parse("((((((1))))))"))
-//println(E.parse("(((((((1)))))))"))
+println(E.parse("((((((1))))))"))
+println(E.parse("(((((((1)))))))"))
 //println(E.parse("((((((((1))))))))"))
 
 
-// faster because of merge
+// faster because of merge in the +/- case
 lazy val E2: Parser[String, Int] = {
-  (T2 ~ (p"+" || p"-") ~ E2).mapp[Int]{ case ((x, y), z) => if (y == "+") x + z else x - z} || T2 }
+  (T2 ~ (p"+" || p"-") ~ E2).map[Int]{ case ((x, y), z) => if (y == "+") x + z else x - z} || T2 }
 lazy val T2: Parser[String, Int] = {
-  (F2 ~ p"*" ~ T2).mapp[Int]{ case ((x, _), z) => x * z } || F2 }
+  (F2 ~ p"*" ~ T2).map[Int]{ case ((x, _), z) => x * z } || F2 }
 lazy val F2: Parser[String, Int] = {
-  (p"(" ~ E2 ~ p")").mapp[Int]{ case ((_, y), _) => y } || NumParserInt }
+  (p"(" ~ E2 ~ p")").map[Int]{ case ((_, y), _) => y } || NumParserInt }
 
 
-println("Runtime problem")
+println("mitigated by merging clauses")
 println(E2.parse("1"))
 println(E2.parse("(1)"))
 println(E2.parse("((1))"))
 println(E2.parse("(((1)))"))
 println(E2.parse("((((1))))"))
-//println(E2.parse("((((((1))))))"))
-//println(E2.parse("(((((((1)))))))"))
-//println(E2.parse("((((((((1))))))))"))
\ No newline at end of file
+println(E2.parse("((((((1))))))"))
+println(E2.parse("(((((((1)))))))"))
+println(E2.parse("((((((((1))))))))"))
\ No newline at end of file
--- a/progs/parser-combinators/comb2.sc	Fri Sep 15 10:49:33 2023 +0100
+++ b/progs/parser-combinators/comb2.sc	Sun Sep 17 19:12:57 2023 +0100
@@ -43,7 +43,7 @@
 }
 
 // map parser
-class MapParser[I, T, S](p: => Parser[I, T], 
+class maparser[I, T, S](p: => Parser[I, T], 
                          f: T => S)(using I => Seq[_]) extends Parser[I, S] {
   def parse(in: I) = for ((hd, tl) <- p.parse(in)) yield (f(hd), tl)
 }
@@ -93,7 +93,7 @@
 extension [I, T](p: Parser[I, T])(using I => Seq[_]) {
   def ||(q : => Parser[I, T]) = new AltParser[I, T](p, q)
   def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-  def mapp[S](f: => T => S) = new MapParser[I, T, S](p, f)
+  def map[S](f: => T => S) = new maparser[I, T, S](p, f)
 }
 
 
@@ -125,47 +125,47 @@
 
 // arithmetic expressions
 lazy val AExp: Parser[String, AExp] = 
-  (Te ~ p"+" ~ AExp).mapp[AExp]{ case x ~ _ ~ z => Aop("+", x, z) } ||
-  (Te ~ p"-" ~ AExp).mapp[AExp]{ case x ~ _ ~ z => Aop("-", x, z) } || Te
+  (Te ~ p"+" ~ AExp).map[AExp]{ case x ~ _ ~ z => Aop("+", x, z) } ||
+  (Te ~ p"-" ~ AExp).map[AExp]{ case x ~ _ ~ z => Aop("-", x, z) } || Te
 lazy val Te: Parser[String, AExp] = 
-  (Fa ~ p"*" ~ Te).mapp[AExp]{ case x ~ _ ~ z => Aop("*", x, z) } || 
-  (Fa ~ p"/" ~ Te).mapp[AExp]{ case x ~ _ ~ z => Aop("/", x, z) } || Fa  
+  (Fa ~ p"*" ~ Te).map[AExp]{ case x ~ _ ~ z => Aop("*", x, z) } || 
+  (Fa ~ p"/" ~ Te).map[AExp]{ case x ~ _ ~ z => Aop("/", x, z) } || Fa  
 lazy val Fa: Parser[String, AExp] = 
-   (p"(" ~ AExp ~ p")").mapp{ case _ ~ y ~ _ => y } || 
-   IdParser.mapp(Var) || 
-   NumParser.mapp(Num)
+   (p"(" ~ AExp ~ p")").map{ case _ ~ y ~ _ => y } || 
+   IdParser.map(Var) || 
+   NumParser.map(Num)
 
 // boolean expressions with some simple nesting
 lazy val BExp: Parser[String, BExp] = 
-   (AExp ~ p"==" ~ AExp).mapp[BExp]{ case x ~ _ ~ z => Bop("==", x, z) } || 
-   (AExp ~ p"!=" ~ AExp).mapp[BExp]{ case x ~ _ ~ z => Bop("!=", x, z) } || 
-   (AExp ~ p"<" ~ AExp).mapp[BExp]{ case x ~ _ ~ z => Bop("<", x, z) } || 
-   (AExp ~ p">" ~ AExp).mapp[BExp]{ case x ~ _ ~ z => Bop(">", x, z) } ||
-   (p"(" ~ BExp ~ p")" ~ p"&&" ~ BExp).mapp[BExp]{ case _ ~ y ~ _ ~ _ ~ v => And(y, v) } ||
-   (p"(" ~ BExp ~ p")" ~ p"||" ~ BExp).mapp[BExp]{ case _ ~ y ~ _ ~ _ ~ v => Or(y, v) } ||
-   (p"true".mapp[BExp]{ _ => True }) || 
-   (p"false".mapp[BExp]{ _ => False }) ||
-   (p"(" ~ BExp ~ p")").mapp[BExp]{ case _ ~ x ~ _ => x }
+   (AExp ~ p"==" ~ AExp).map[BExp]{ case x ~ _ ~ z => Bop("==", x, z) } || 
+   (AExp ~ p"!=" ~ AExp).map[BExp]{ case x ~ _ ~ z => Bop("!=", x, z) } || 
+   (AExp ~ p"<" ~ AExp).map[BExp]{ case x ~ _ ~ z => Bop("<", x, z) } || 
+   (AExp ~ p">" ~ AExp).map[BExp]{ case x ~ _ ~ z => Bop(">", x, z) } ||
+   (p"(" ~ BExp ~ p")" ~ p"&&" ~ BExp).map[BExp]{ case _ ~ y ~ _ ~ _ ~ v => And(y, v) } ||
+   (p"(" ~ BExp ~ p")" ~ p"||" ~ BExp).map[BExp]{ case _ ~ y ~ _ ~ _ ~ v => Or(y, v) } ||
+   (p"true".map[BExp]{ _ => True }) || 
+   (p"false".map[BExp]{ _ => False }) ||
+   (p"(" ~ BExp ~ p")").map[BExp]{ case _ ~ x ~ _ => x }
 
 // a single statement 
 lazy val Stmt: Parser[String, Stmt] =
-  ((p"skip".mapp[Stmt]{_ => Skip }) ||
-   (IdParser ~ p":=" ~ AExp).mapp[Stmt]{ case x ~ _ ~ z => Assign(x, z) } ||
-   (p"write(" ~ IdParser ~ p")").mapp[Stmt]{ case _ ~ y ~ _ => Write(y) } ||
+  ((p"skip".map[Stmt]{_ => Skip }) ||
+   (IdParser ~ p":=" ~ AExp).map[Stmt]{ case x ~ _ ~ z => Assign(x, z) } ||
+   (p"write(" ~ IdParser ~ p")").map[Stmt]{ case _ ~ y ~ _ => Write(y) } ||
    (p"if" ~ BExp ~ p"then" ~ Block ~ p"else" ~ Block)
-     .mapp[Stmt]{ case _ ~ y ~ _ ~ u ~ _ ~ w => If(y, u, w) } ||
-   (p"while" ~ BExp ~ p"do" ~ Block).mapp[Stmt]{ case _ ~ y ~ _ ~ w => While(y, w) })   
+     .map[Stmt]{ case _ ~ y ~ _ ~ u ~ _ ~ w => If(y, u, w) } ||
+   (p"while" ~ BExp ~ p"do" ~ Block).map[Stmt]{ case _ ~ y ~ _ ~ w => While(y, w) })   
  
  
 // statements
 lazy val Stmts: Parser[String, Block] =
-  (Stmt ~ p";" ~ Stmts).mapp[Block]{ case x ~ _ ~ z => x :: z } ||
-  (Stmt.mapp[Block]{ s => List(s) })
+  (Stmt ~ p";" ~ Stmts).map[Block]{ case x ~ _ ~ z => x :: z } ||
+  (Stmt.map[Block]{ s => List(s) })
 
 // blocks (enclosed in curly braces)
 lazy val Block: Parser[String, Block] =
-  ((p"{" ~ Stmts ~ p"}").mapp{ case _ ~ y ~ _ => y } || 
-   (Stmt.mapp(s => List(s))))
+  ((p"{" ~ Stmts ~ p"}").map{ case _ ~ y ~ _ => y } || 
+   (Stmt.map(s => List(s))))
 
 
 // Examples