diff -r c616ec6b1e3c -r c603b27083f3 Fahad/Scala/POSIX.sc --- a/Fahad/Scala/POSIX.sc Wed Jan 21 12:32:17 2015 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,305 +0,0 @@ -package greeter - - -object POSIX { - println("Posix Algorithm") //> Posix Algorithm - - abstract class Rexp - case object NULL extends Rexp - case object EMPTY extends Rexp - case class CHAR(c: Char) extends Rexp - case class ALT(r1: Rexp, r2: Rexp) extends Rexp - case class SEQ(r1: Rexp, r2: Rexp) extends Rexp - case class STAR(r: Rexp) extends Rexp - case class RECD(x: String, r: Rexp) extends Rexp - - abstract class Val - case object Void extends Val - case class Chr(c: Char) extends Val - case class Sequ(v1: Val, v2: Val) extends Val - case class Left(v: Val) extends Val - case class Right(v: Val) extends Val - case class Stars(vs: List[Val]) extends Val - case class Rec(x: String, v: Val) extends Val - - def charlist2rexp(s: List[Char]): Rexp = s match { - case Nil => EMPTY - case c :: Nil => CHAR(c) - case c :: s => SEQ(CHAR(c), charlist2rexp(s)) - } //> charlist2rexp: (s: List[Char])greeter.POSIX.Rexp - implicit def string2rexp(s: String): Rexp = charlist2rexp(s.toList) - //> string2rexp: (s: String)greeter.POSIX.Rexp - - implicit def RexpOps(r: Rexp) = new { - def |(s: Rexp) = ALT(r, s) - def % = STAR(r) - def ~(s: Rexp) = SEQ(r, s) - } //> RexpOps: (r: greeter.POSIX.Rexp)AnyRef{def |(s: greeter.POSIX.Rexp): greete - //| r.POSIX.ALT; def %: greeter.POSIX.STAR; def ~(s: greeter.POSIX.Rexp): greet - //| er.POSIX.SEQ} - - implicit def stringOps(s: String) = new { - def |(r: Rexp) = ALT(s, r) - def |(r: String) = ALT(s, r) - def % = STAR(s) - def ~(r: Rexp) = SEQ(s, r) - def ~(r: String) = SEQ(s, r) - def $(r: Rexp) = RECD(s, r) - } //> stringOps: (s: String)AnyRef{def |(r: greeter.POSIX.Rexp): greeter.POSIX.AL - //| T; def |(r: String): greeter.POSIX.ALT; def %: greeter.POSIX.STAR; def ~(r: - //| greeter.POSIX.Rexp): greeter.POSIX.SEQ; def ~(r: String): greeter.POSIX.SE - //| Q; def $(r: greeter.POSIX.Rexp): greeter.POSIX.RECD} - - // size of a regular expressions - for testing purposes - def size(r: Rexp): Int = r match { - case NULL => 1 - case EMPTY => 1 - case CHAR(_) => 1 - case ALT(r1, r2) => 1 + size(r1) + size(r2) - case SEQ(r1, r2) => 1 + size(r1) + size(r2) - case STAR(r) => 1 + size(r) - case RECD(_, r) => 1 + size(r) - } //> size: (r: greeter.POSIX.Rexp)Int - - // nullable function: tests whether the regular - // expression can recognise the empty string - def nullable(r: Rexp): Boolean = r match { - case NULL => false - case EMPTY => true - case CHAR(_) => false - case ALT(r1, r2) => nullable(r1) || nullable(r2) - case SEQ(r1, r2) => nullable(r1) && nullable(r2) - case STAR(_) => true - case RECD(_, r1) => nullable(r1) - } //> nullable: (r: greeter.POSIX.Rexp)Boolean - - // derivative of a regular expression w.r.t. a character - def der(c: Char, r: Rexp): Rexp = r match { - case NULL => NULL - case EMPTY => NULL - case CHAR(d) => if (c == d) EMPTY else NULL - case ALT(r1, r2) => ALT(der(c, r1), der(c, r2)) - case SEQ(r1, r2) => - if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2)) - else SEQ(der(c, r1), r2) - case STAR(r) => SEQ(der(c, r), STAR(r)) - case RECD(_, r1) => der(c, r1) - } //> der: (c: Char, r: greeter.POSIX.Rexp)greeter.POSIX.Rexp - - // 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, der(c, r)) - } //> ders: (s: List[Char], r: greeter.POSIX.Rexp)greeter.POSIX.Rexp - - // extracts a string from value - def flatten(v: Val): String = v match { - case Void => "" - case Chr(c) => c.toString - case Left(v) => flatten(v) - case Right(v) => flatten(v) - case Sequ(v1, v2) => flatten(v1) + flatten(v2) - case Stars(vs) => vs.map(flatten).mkString - case Rec(_, v) => flatten(v) - } //> flatten: (v: greeter.POSIX.Val)String - - // extracts an environment from a value - def env(v: Val): List[(String, String)] = v match { - case Void => Nil - case Chr(c) => Nil - case Left(v) => env(v) - case Right(v) => env(v) - case Sequ(v1, v2) => env(v1) ::: env(v2) - case Stars(vs) => vs.flatMap(env) - case Rec(x, v) => (x, flatten(v)) :: env(v) - } //> env: (v: greeter.POSIX.Val)List[(String, String)] - - def mkeps(r: Rexp): Val = r match { - case EMPTY => Void - case ALT(r1, r2) => - if (nullable(r1)) Left(mkeps(r1)) else Right(mkeps(r2)) - case SEQ(r1, r2) => Sequ(mkeps(r1), mkeps(r2)) - case STAR(r) => Stars(Nil) - case RECD(x, r) => Rec(x, mkeps(r)) - } //> mkeps: (r: greeter.POSIX.Rexp)greeter.POSIX.Val - - def inj(r: Rexp, c: Char, v: Val): Val = (r, v) match { - case (STAR(r), Sequ(v1, Stars(vs))) => Stars(inj(r, c, v1) :: vs) - case (SEQ(r1, r2), Sequ(v1, v2)) => Sequ(inj(r1, c, v1), v2) - case (SEQ(r1, r2), Left(Sequ(v1, v2))) => Sequ(inj(r1, c, v1), v2) - case (SEQ(r1, r2), Right(v2)) => Sequ(mkeps(r1), inj(r2, c, v2)) - case (ALT(r1, r2), Left(v1)) => Left(inj(r1, c, v1)) - case (ALT(r1, r2), Right(v2)) => Right(inj(r2, c, v2)) - case (CHAR(d), Void) => Chr(d) - case (RECD(x, r1), _) => Rec(x, inj(r1, c, v)) - } //> inj: (r: greeter.POSIX.Rexp, c: Char, v: greeter.POSIX.Val)greeter.POSIX.Va - //| l - - // main lexing function (produces a value) - def lex(r: Rexp, s: List[Char]): Val = s match { - case Nil => if (nullable(r)) mkeps(r) else throw new Exception("Not matched") - case c :: cs => inj(r, c, lex(der(c, r), cs)) - } //> lex: (r: greeter.POSIX.Rexp, s: List[Char])greeter.POSIX.Val - - def lexing(r: Rexp, s: String): Val = lex(r, s.toList) - //> lexing: (r: greeter.POSIX.Rexp, s: String)greeter.POSIX.Val - - val r = (("1" $ "a") | (("2" $ "b") | ("3" $ "ab"))).% - //> r : greeter.POSIX.STAR = STAR(ALT(RECD(1,CHAR(a)),ALT(RECD(2,CHAR(b)),RECD - //| (3,SEQ(CHAR(a),CHAR(b)))))) - env(lexing(r, "ba")) //> res0: List[(String, String)] = List((2,b), (1,a)) - - val r1 = "a" | "b" //> r1 : greeter.POSIX.ALT = ALT(CHAR(a),CHAR(b)) - lexing(r1, "a") //> res1: greeter.POSIX.Val = Left(Chr(a)) - - // Lexing Rules for a Small While Language - - def PLUS(r: Rexp) = r ~ r.% //> PLUS: (r: greeter.POSIX.Rexp)greeter.POSIX.SEQ - val SYM = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z" - //> SYM : greeter.POSIX.ALT = ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT( - //| ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(a),CHAR(b)),CHAR(c - //| )),CHAR(d)),CHAR(e)),CHAR(f)),CHAR(g)),CHAR(h)),CHAR(i)),CHAR(j)),CHAR(k)), - //| CHAR(l)),CHAR(m)),CHAR(n)),CHAR(o)),CHAR(p)),CHAR(q)),CHAR(r)),CHAR(s)),CHA - //| R(t)),CHAR(u)),CHAR(v)),CHAR(w)),CHAR(x)),CHAR(y)),CHAR(z)) - val DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" - //> DIGIT : greeter.POSIX.ALT = ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(0),CH - //| AR(1)),CHAR(2)),CHAR(3)),CHAR(4)),CHAR(5)),CHAR(6)),CHAR(7)),CHAR(8)),CHAR( - //| 9)) - val ID = SYM ~ (SYM | DIGIT).% //> ID : greeter.POSIX.SEQ = SEQ(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(A - //| LT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(a),CHAR(b)),CHA - //| R(c)),CHAR(d)),CHAR(e)),CHAR(f)),CHAR(g)),CHAR(h)),CHAR(i)),CHAR(j)),CHAR(k - //| )),CHAR(l)),CHAR(m)),CHAR(n)),CHAR(o)),CHAR(p)),CHAR(q)),CHAR(r)),CHAR(s)), - //| CHAR(t)),CHAR(u)),CHAR(v)),CHAR(w)),CHAR(x)),CHAR(y)),CHAR(z)),STAR(ALT(ALT - //| (ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(AL - //| T(ALT(ALT(ALT(ALT(ALT(CHAR(a),CHAR(b)),CHAR(c)),CHAR(d)),CHAR(e)),CHAR(f)), - //| CHAR(g)),CHAR(h)),CHAR(i)),CHAR(j)),CHAR(k)),CHAR(l)),CHAR(m)),CHAR(n)),CHA - //| R(o)),CHAR(p)),CHAR(q)),CHAR(r)),CHAR(s)),CHAR(t)),CHAR(u)),CHAR(v)),CHAR(w - //| )),CHAR(x)),CHAR(y)),CHAR(z)),ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(0),C - //| HAR(1)),CHAR(2)),CHAR(3)),CHAR(4)),CHAR(5)),CHAR(6)),CHAR(7)),CHAR(8)),CHAR - //| (9))))) - val NUM = PLUS(DIGIT) //> NUM : greeter.POSIX.SEQ = SEQ(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(0), - //| CHAR(1)),CHAR(2)),CHAR(3)),CHAR(4)),CHAR(5)),CHAR(6)),CHAR(7)),CHAR(8)),CHA - //| R(9)),STAR(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(CHAR(0),CHAR(1)),CHAR(2)),CH - //| AR(3)),CHAR(4)),CHAR(5)),CHAR(6)),CHAR(7)),CHAR(8)),CHAR(9)))) - val KEYWORD: Rexp = "skip" | "while" | "do" | "if" | "then" | "else" | "read" | "write" | "true" | "false" - //> KEYWORD : greeter.POSIX.Rexp = ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(SEQ(CHA - //| R(s),SEQ(CHAR(k),SEQ(CHAR(i),CHAR(p)))),SEQ(CHAR(w),SEQ(CHAR(h),SEQ(CHAR(i) - //| ,SEQ(CHAR(l),CHAR(e)))))),SEQ(CHAR(d),CHAR(o))),SEQ(CHAR(i),CHAR(f))),SEQ(C - //| HAR(t),SEQ(CHAR(h),SEQ(CHAR(e),CHAR(n))))),SEQ(CHAR(e),SEQ(CHAR(l),SEQ(CHAR - //| (s),CHAR(e))))),SEQ(CHAR(r),SEQ(CHAR(e),SEQ(CHAR(a),CHAR(d))))),SEQ(CHAR(w) - //| ,SEQ(CHAR(r),SEQ(CHAR(i),SEQ(CHAR(t),CHAR(e)))))),SEQ(CHAR(t),SEQ(CHAR(r),S - //| EQ(CHAR(u),CHAR(e))))),SEQ(CHAR(f),SEQ(CHAR(a),SEQ(CHAR(l),SEQ(CHAR(s),CHAR - //| (e)))))) - val SEMI: Rexp = ";" //> SEMI : greeter.POSIX.Rexp = CHAR(;) - val OP: Rexp = ":=" | "==" | "-" | "+" | "*" | "!=" | "<" | ">" | "<=" | ">=" | "%" | "/" - //> OP : greeter.POSIX.Rexp = ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(SEQ( - //| CHAR(:),CHAR(=)),SEQ(CHAR(=),CHAR(=))),CHAR(-)),CHAR(+)),CHAR(*)),SEQ(CHAR( - //| !),CHAR(=))),CHAR(<)),CHAR(>)),SEQ(CHAR(<),CHAR(=))),SEQ(CHAR(>),CHAR(=))), - //| CHAR(%)),CHAR(/)) - val WHITESPACE = PLUS(" " | "\n" | "\t") //> WHITESPACE : greeter.POSIX.SEQ = SEQ(ALT(ALT(CHAR( ),CHAR( - //| )),CHAR( )),STAR(ALT(ALT(CHAR( ),CHAR( - //| )),CHAR( )))) - val RPAREN: Rexp = ")" //> RPAREN : greeter.POSIX.Rexp = CHAR()) - val LPAREN: Rexp = "(" //> LPAREN : greeter.POSIX.Rexp = CHAR(() - val BEGIN: Rexp = "{" //> BEGIN : greeter.POSIX.Rexp = CHAR({) - val END: Rexp = "}" //> END : greeter.POSIX.Rexp = CHAR(}) - - /* - * val WHILE_REGS = (("k" $ KEYWORD) | - ("i" $ ID) | - ("o" $ OP) | - ("n" $ NUM) | - ("s" $ SEMI) | - ("p" $ (LPAREN | RPAREN)) | - ("b" $ (BEGIN | END)) | - ("w" $ WHITESPACE)).% -*/ - - val WHILE_REGS = (KEYWORD | - ID | - OP | - NUM | - SEMI | - LPAREN | RPAREN | - BEGIN | END | - WHITESPACE).% //> WHILE_REGS : greeter.POSIX.STAR = STAR(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT - //| (ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(SEQ(CHAR(s),SEQ(CHAR(k),SEQ(CHAR(i),CH - //| AR(p)))),SEQ(CHAR(w),SEQ(CHAR(h),SEQ(CHAR(i),SEQ(CHAR(l),CHAR(e)))))),SEQ(C - //| HAR(d),CHAR(o))),SEQ(CHAR(i),CHAR(f))),SEQ(CHAR(t),SEQ(CHAR(h),SEQ(CHAR(e), - //| CHAR(n))))),SEQ(CHAR(e),SEQ(CHAR(l),SEQ(CHAR(s),CHAR(e))))),SEQ(CHAR(r),SEQ - //| (CHAR(e),SEQ(CHAR(a),CHAR(d))))),SEQ(CHAR(w),SEQ(CHAR(r),SEQ(CHAR(i),SEQ(CH - //| AR(t),CHAR(e)))))),SEQ(CHAR(t),SEQ(CHAR(r),SEQ(CHAR(u),CHAR(e))))),SEQ(CHAR - //| (f),SEQ(CHAR(a),SEQ(CHAR(l),SEQ(CHAR(s),CHAR(e)))))),SEQ(ALT(ALT(ALT(ALT(AL - //| T(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(ALT(A - //| LT(ALT(CHAR(a),CHAR(b)),CHAR(c)),CHAR(d)),CHAR(e)),CHAR(f)),CHAR(g)),CHAR(h - //| )),CHAR(i)),CHAR(j)),CHAR(k)),CHAR(l)),CHAR(m)),CHAR(n)),CHAR(o)),CHAR(p)), - //| CHAR(q)),CHAR(r)),CHAR(s)),CHAR(t)),CHAR(u)),CHAR(v)),CHAR(w)),CHAR(x)),CHA - //| R(y)),CHAR(z)),STAR(ALT - //| Output exceeds cutoff limit. - - // Some Tests - //============ - - def time[T](code: => T) = { - val start = System.nanoTime() - val result = code - val end = System.nanoTime() - println((end - start) / 1.0e9) - result - } //> time: [T](code: => T)T - - - val abc = List('a', 'b', 'c') //> abc : List[Char] = List(a, b, c) - val nullRexp = null //> nullRexp : Null = null - val myRexp = charlist2rexp(abc) //> myRexp : greeter.POSIX.Rexp = SEQ(CHAR(a),SEQ(CHAR(b),CHAR(c))) - val myRexp2 = string2rexp("FahadAusaf") //> myRexp2 : greeter.POSIX.Rexp = SEQ(CHAR(F),SEQ(CHAR(a),SEQ(CHAR(h),SEQ(CHA - //| R(a),SEQ(CHAR(d),SEQ(CHAR(A),SEQ(CHAR(u),SEQ(CHAR(s),SEQ(CHAR(a),CHAR(f)))) - //| )))))) - - RexpOps(myRexp2) //> res2: AnyRef{def |(s: greeter.POSIX.Rexp): greeter.POSIX.ALT; def %: greete - //| r.POSIX.STAR; def ~(s: greeter.POSIX.Rexp): greeter.POSIX.SEQ} = greeter.PO - //| SIX$$anonfun$main$1$$anon$1@37ecb28e - - stringOps("Fahad") //> res3: AnyRef{def |(r: greeter.POSIX.Rexp): greeter.POSIX.ALT; def |(r: Stri - //| ng): greeter.POSIX.ALT; def %: greeter.POSIX.STAR; def ~(r: greeter.POSIX.R - //| exp): greeter.POSIX.SEQ; def ~(r: String): greeter.POSIX.SEQ; def $(r: gree - //| ter.POSIX.Rexp): greeter.POSIX.RECD} = greeter.POSIX$$anonfun$main$1$$anon$ - //| 2@14bea551 - - size(myRexp2) //> res4: Int = 19 - nullable(nullRexp) //> scala.MatchError: null - //| at greeter.POSIX$$anonfun$main$1.nullable$1(greeter.POSIX.scala:59) - //| at greeter.POSIX$$anonfun$main$1.apply$mcV$sp(greeter.POSIX.scala:202) - //| at org.scalaide.worksheet.runtime.library.WorksheetSupport$$anonfun$$exe - //| cute$1.apply$mcV$sp(WorksheetSupport.scala:76) - //| at org.scalaide.worksheet.runtime.library.WorksheetSupport$.redirected(W - //| orksheetSupport.scala:65) - //| at org.scalaide.worksheet.runtime.library.WorksheetSupport$.$execute(Wor - //| ksheetSupport.scala:75) - //| at greeter.POSIX$.main(greeter.POSIX.scala:3) - //| at greeter.POSIX.main(greeter.POSIX.scala) - - val newRexp = der('a',myRexp) - - - - - - - - - - - - - - - - - - - - - - //this is some crap -}