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// A simple lexer inspired by work of Sulzmann & Lu
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//==================================================
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//
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// Call the test cases with
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//
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// amm lexer.sc small
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// amm lexer.sc fib
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// amm lexer.sc loops
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// amm lexer.sc email
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//
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// amm lexer.sc all
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// regular expressions including records
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abstract class Rexp
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case object ZERO extends Rexp
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case object ONE extends Rexp
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case object ANYCHAR extends Rexp
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case class CHAR(c: Char) extends Rexp
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case class ALTS(r1: Rexp, r2: Rexp) extends Rexp
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case class SEQ(r1: Rexp, r2: Rexp) extends Rexp
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case class STAR(r: Rexp) extends Rexp
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case class RECD(x: String, r: Rexp) extends Rexp
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case class NTIMES(n: Int, r: Rexp) extends Rexp
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case class OPTIONAL(r: Rexp) extends Rexp
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case class NOT(r: Rexp) extends Rexp
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// records for extracting strings or tokens
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// values
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abstract class Val
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case object Empty extends Val
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case class Chr(c: Char) extends Val
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case class Sequ(v1: Val, v2: Val) extends Val
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case class Left(v: Val) extends Val
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case class Right(v: Val) extends Val
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case class Stars(vs: List[Val]) extends Val
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case class Rec(x: String, v: Val) extends Val
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case class Ntime(vs: List[Val]) extends Val
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case class Optionall(v: Val) extends Val
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case class Nots(s: String) extends Val
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abstract class Bit
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case object Z extends Bit
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case object S extends Bit
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type Bits = List[Bit]
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abstract class ARexp
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case object AZERO extends ARexp
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case class AONE(bs: Bits) extends ARexp
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case class ACHAR(bs: Bits, c: Char) extends ARexp
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case class AALTS(bs: Bits, rs: List[ARexp]) extends ARexp
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case class ASEQ(bs: Bits, r1: ARexp, r2: ARexp) extends ARexp
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case class ASTAR(bs: Bits, r: ARexp) extends ARexp
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case class ANOT(bs: Bits, r: ARexp) extends ARexp
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case class AANYCHAR(bs: Bits) extends ARexp
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// some convenience for typing in regular expressions
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def charlist2rexp(s : List[Char]): Rexp = s match {
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case Nil => ONE
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case c::Nil => CHAR(c)
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case c::s => SEQ(CHAR(c), charlist2rexp(s))
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}
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implicit def string2rexp(s : String) : Rexp =
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charlist2rexp(s.toList)
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implicit def RexpOps(r: Rexp) = new {
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def | (s: Rexp) = ALTS(r, s)
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def % = STAR(r)
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def ~ (s: Rexp) = SEQ(r, s)
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}
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implicit def stringOps(s: String) = new {
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def | (r: Rexp) = ALTS(s, r)
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def | (r: String) = ALTS(s, r)
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def % = STAR(s)
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def ~ (r: Rexp) = SEQ(s, r)
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def ~ (r: String) = SEQ(s, r)
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def $ (r: Rexp) = RECD(s, r)
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}
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def nullable(r: Rexp) : Boolean = r match {
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case ZERO => false
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case ONE => true
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case CHAR(_) => false
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case ANYCHAR => false
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case ALTS(r1, r2) => nullable(r1) || nullable(r2)
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case SEQ(r1, r2) => nullable(r1) && nullable(r2)
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case STAR(_) => true
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case RECD(_, r1) => nullable(r1)
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case NTIMES(n, r) => if (n == 0) true else nullable(r)
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case OPTIONAL(r) => true
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case NOT(r) => !nullable(r)
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}
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def der(c: Char, r: Rexp) : Rexp = r match {
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case ZERO => ZERO
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case ONE => ZERO
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case CHAR(d) => if (c == d) ONE else ZERO
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case ANYCHAR => ONE
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case ALTS(r1, r2) => ALTS(der(c, r1), der(c, r2))
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case SEQ(r1, r2) =>
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if (nullable(r1)) ALTS(SEQ(der(c, r1), r2), der(c, r2))
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else SEQ(der(c, r1), r2)
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case STAR(r) => SEQ(der(c, r), STAR(r))
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case RECD(_, r1) => der(c, r1)
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case NTIMES(n, r) => if(n > 0) SEQ(der(c, r), NTIMES(n - 1, r)) else ZERO
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case OPTIONAL(r) => der(c, r)
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case NOT(r) => NOT(der(c, r))
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}
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// extracts a string from a value
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def flatten(v: Val) : String = v match {
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case Empty => ""
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case Chr(c) => c.toString
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case Left(v) => flatten(v)
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case Right(v) => flatten(v)
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case Sequ(v1, v2) => flatten(v1) ++ flatten(v2)
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case Stars(vs) => vs.map(flatten).mkString
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case Ntime(vs) => vs.map(flatten).mkString
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case Optionall(v) => flatten(v)
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case Rec(_, v) => flatten(v)
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}
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// extracts an environment from a value;
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// used for tokenising a string
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def env(v: Val) : List[(String, String)] = v match {
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case Empty => Nil
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case Chr(c) => Nil
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case Left(v) => env(v)
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case Right(v) => env(v)
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case Sequ(v1, v2) => env(v1) ::: env(v2)
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case Stars(vs) => vs.flatMap(env)
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case Ntime(vs) => vs.flatMap(env)
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case Rec(x, v) => (x, flatten(v))::env(v)
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case Optionall(v) => env(v)
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case Nots(s) => ("Negative", s) :: Nil
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}
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// The injection and mkeps part of the lexer
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//===========================================
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def mkeps(r: Rexp) : Val = r match {
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case ONE => Empty
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case ALTS(r1, r2) =>
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if (nullable(r1)) Left(mkeps(r1)) else Right(mkeps(r2))
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case SEQ(r1, r2) => Sequ(mkeps(r1), mkeps(r2))
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case STAR(r) => Stars(Nil)
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case RECD(x, r) => Rec(x, mkeps(r))
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case NTIMES(n, r) => Ntime(List.fill(n)(mkeps(r)))
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case OPTIONAL(r) => Optionall(Empty)
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case NOT(rInner) => if(nullable(rInner)) throw new Exception("error")
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else Nots("")//Nots(s.reverse.toString)
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// case NOT(ZERO) => Empty
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// case NOT(CHAR(c)) => Empty
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// case NOT(SEQ(r1, r2)) => Sequ(mkeps(NOT(r1)), mkeps(NOT(r2)))
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// case NOT(ALTS(r1, r2)) => if(!nullable(r1)) Left(mkeps(NOT(r1))) else Right(mkeps(NOT(r2)))
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// case NOT(STAR(r)) => Stars(Nil)
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}
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def inj(r: Rexp, c: Char, v: Val) : Val = (r, v) match {
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case (STAR(r), Sequ(v1, Stars(vs))) => Stars(inj(r, c, v1)::vs)
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case (SEQ(r1, r2), Sequ(v1, v2)) => Sequ(inj(r1, c, v1), v2)
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case (SEQ(r1, r2), Left(Sequ(v1, v2))) => Sequ(inj(r1, c, v1), v2)
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case (SEQ(r1, r2), Right(v2)) => Sequ(mkeps(r1), inj(r2, c, v2))
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case (ALTS(r1, r2), Left(v1)) => Left(inj(r1, c, v1))
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case (ALTS(r1, r2), Right(v2)) => Right(inj(r2, c, v2))
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case (CHAR(d), Empty) => Chr(c)
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case (RECD(x, r1), _) => Rec(x, inj(r1, c, v))
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case (NTIMES(n, r), Sequ(v1, Ntime(vs))) => Ntime(inj(r, c, v1)::vs)
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case (OPTIONAL(r), v) => Optionall(inj(r, c, v))
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case (NOT(r), Nots(s)) => Nots(c.toString ++ s)
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case (ANYCHAR, Empty) => Chr(c)
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}
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// some "rectification" functions for simplification
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def F_ID(v: Val): Val = v
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def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))
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def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))
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def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
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case Right(v) => Right(f2(v))
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case Left(v) => Left(f1(v))
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}
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def F_SEQ(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
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case Sequ(v1, v2) => Sequ(f1(v1), f2(v2))
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}
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def F_SEQ_Empty1(f1: Val => Val, f2: Val => Val) =
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(v:Val) => Sequ(f1(Empty), f2(v))
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def F_SEQ_Empty2(f1: Val => Val, f2: Val => Val) =
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(v:Val) => Sequ(f1(v), f2(Empty))
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def F_ERROR(v: Val): Val = throw new Exception("error")
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// simplification
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def simp(r: Rexp): (Rexp, Val => Val) = r match {
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case ALTS(r1, r2) => {
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val (r1s, f1s) = simp(r1)
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val (r2s, f2s) = simp(r2)
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(r1s, r2s) match {
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case (ZERO, _) => (r2s, F_RIGHT(f2s))
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case (_, ZERO) => (r1s, F_LEFT(f1s))
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case _ => if (r1s == r2s) (r1s, F_LEFT(f1s))
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else (ALTS (r1s, r2s), F_ALT(f1s, f2s))
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}
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}
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case SEQ(r1, r2) => {
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val (r1s, f1s) = simp(r1)
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val (r2s, f2s) = simp(r2)
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(r1s, r2s) match {
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case (ZERO, _) => (ZERO, F_ERROR)
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case (_, ZERO) => (ZERO, F_ERROR)
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case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))
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case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))
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case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))
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}
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}
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case r => (r, F_ID)
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}
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// lexing functions including simplification
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def lex_simp(r: Rexp, s: List[Char]) : Val = s match {
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case Nil => if (nullable(r)) mkeps(r) else
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{ throw new Exception(s"lexing error $r not nullable") }
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case c::cs => {
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val (r_simp, f_simp) = simp(der(c, r))
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inj(r, c, f_simp(lex_simp(r_simp, cs)))
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}
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}
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def lexing_simp(r: Rexp, s: String) =
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env(lex_simp(r, s.toList))
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// The Lexing Rules for the WHILE Language
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def PLUS(r: Rexp) = r ~ r.%
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def Range(s : List[Char]) : Rexp = s match {
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case Nil => ZERO
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case c::Nil => CHAR(c)
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case c::s => ALTS(CHAR(c), Range(s))
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}
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def RANGE(s: String) = Range(s.toList)
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val SYM = RANGE("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_")
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val DIGIT = RANGE("0123456789")
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val ID = SYM ~ (SYM | DIGIT).%
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val NUM = PLUS(DIGIT)
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val KEYWORD : Rexp = "skip" | "while" | "do" | "if" | "then" | "else" | "read" | "write"
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val SEMI: Rexp = ";"
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val OP: Rexp = ":=" | "=" | "-" | "+" | "*" | "!=" | "<" | ">"
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val WHITESPACE = PLUS(" " | "\n" | "\t" | "\r")
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val RPAREN: Rexp = "{"
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val LPAREN: Rexp = "}"
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val STRING: Rexp = "\"" ~ SYM.% ~ "\""
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//ab \ a --> 1b
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//
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val WHILE_REGS = (("k" $ KEYWORD) |
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("i" $ ID) |
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("o" $ OP) |
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("n" $ NUM) |
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("s" $ SEMI) |
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("str" $ STRING) |
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("p" $ (LPAREN | RPAREN)) |
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("w" $ WHITESPACE)).%
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val NREGS = NTIMES(5, OPTIONAL(SYM))
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val NREGS1 = ("test" $ NREGS)
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// Two Simple While Tests
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//========================
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val NOTREG = "hehe" ~ NOT((ANYCHAR.%) ~ "haha" ~ (ANYCHAR.%))
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// bnullable function: tests whether the aregular
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// expression can recognise the empty string
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def bnullable (r: ARexp) : Boolean = r match {
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case AZERO => false
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case AONE(_) => true
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case ACHAR(_,_) => false
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case AALTS(_, rs) => rs.exists(bnullable)
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case ASEQ(_, r1, r2) => bnullable(r1) && bnullable(r2)
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case ASTAR(_, _) => true
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case ANOT(_, rn) => !bnullable(rn)
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}
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def mkepsBC(r: ARexp) : Bits = r match {
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case AONE(bs) => bs
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case AALTS(bs, rs) => {
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val n = rs.indexWhere(bnullable)
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bs ++ mkepsBC(rs(n))
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}
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case ASEQ(bs, r1, r2) => bs ++ mkepsBC(r1) ++ mkepsBC(r2)
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case ASTAR(bs, r) => bs ++ List(Z)
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case ANOT(bs, rn) => bs
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}
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def bder(c: Char, r: ARexp) : ARexp = r match {
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case AZERO => AZERO
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case AONE(_) => AZERO
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312 |
case ACHAR(bs, f) => if (c == f) AONE(bs) else AZERO
|
|
|
313 |
case AALTS(bs, rs) => AALTS(bs, rs.map(bder(c, _)))
|
|
|
314 |
case ASEQ(bs, r1, r2) =>
|
|
|
315 |
if (bnullable(r1)) AALTS(bs, ASEQ(Nil, bder(c, r1), r2) :: fuse(mkepsBC(r1), bder(c, r2)) :: Nil )
|
|
|
316 |
else ASEQ(bs, bder(c, r1), r2)
|
|
|
317 |
case ASTAR(bs, r) => ASEQ(bs, fuse(List(S), bder(c, r)), ASTAR(Nil, r))
|
|
|
318 |
case ANOT(bs, rn) => ANOT(bs, bder(c, rn))
|
|
|
319 |
case AANYCHAR(bs) => AONE(bs)
|
|
|
320 |
}
|
|
|
321 |
|
|
|
322 |
def fuse(bs: Bits, r: ARexp) : ARexp = r match {
|
|
|
323 |
case AZERO => AZERO
|
|
|
324 |
case AONE(cs) => AONE(bs ++ cs)
|
|
|
325 |
case ACHAR(cs, f) => ACHAR(bs ++ cs, f)
|
|
|
326 |
case AALTS(cs, rs) => AALTS(bs ++ cs, rs)
|
|
|
327 |
case ASEQ(cs, r1, r2) => ASEQ(bs ++ cs, r1, r2)
|
|
|
328 |
case ASTAR(cs, r) => ASTAR(bs ++ cs, r)
|
|
|
329 |
case ANOT(cs, r) => ANOT(bs ++ cs, r)
|
|
|
330 |
}
|
|
|
331 |
|
|
|
332 |
|
|
|
333 |
def internalise(r: Rexp) : ARexp = r match {
|
|
|
334 |
case ZERO => AZERO
|
|
|
335 |
case ONE => AONE(Nil)
|
|
|
336 |
case CHAR(c) => ACHAR(Nil, c)
|
|
|
337 |
//case PRED(f) => APRED(Nil, f)
|
|
|
338 |
case ALTS(r1, r2) =>
|
|
|
339 |
AALTS(Nil, List(fuse(List(Z), internalise(r1)), fuse(List(S), internalise(r2))))
|
|
|
340 |
// case ALTS(r1::rs) => {
|
|
|
341 |
// val AALTS(Nil, rs2) = internalise(ALTS(rs))
|
|
|
342 |
// AALTS(Nil, fuse(List(Z), internalise(r1)) :: rs2.map(fuse(List(S), _)))
|
|
|
343 |
// }
|
|
|
344 |
case SEQ(r1, r2) => ASEQ(Nil, internalise(r1), internalise(r2))
|
|
|
345 |
case STAR(r) => ASTAR(Nil, internalise(r))
|
|
|
346 |
case RECD(x, r) => internalise(r)
|
|
|
347 |
case NOT(r) => ANOT(Nil, internalise(r))
|
|
|
348 |
case ANYCHAR => AANYCHAR(Nil)
|
|
|
349 |
}
|
|
|
350 |
|
|
|
351 |
|
|
|
352 |
def bsimp(r: ARexp): ARexp =
|
|
|
353 |
{
|
|
|
354 |
r match {
|
|
|
355 |
case ASEQ(bs1, r1, r2) => (bsimp(r1), bsimp(r2)) match {
|
|
|
356 |
case (AZERO, _) => AZERO
|
|
|
357 |
case (_, AZERO) => AZERO
|
|
|
358 |
case (AONE(bs2), r2s) => fuse(bs1 ++ bs2, r2s)
|
|
|
359 |
case (r1s, r2s) => ASEQ(bs1, r1s, r2s)
|
|
|
360 |
}
|
|
|
361 |
case AALTS(bs1, rs) => {
|
|
|
362 |
val rs_simp = rs.map(bsimp(_))
|
|
|
363 |
val flat_res = flats(rs_simp)
|
|
|
364 |
val dist_res = strongDistinctBy(flat_res)//distinctBy(flat_res, erase)
|
|
|
365 |
dist_res match {
|
|
|
366 |
case Nil => AZERO
|
|
|
367 |
case s :: Nil => fuse(bs1, s)
|
|
|
368 |
case rs => AALTS(bs1, rs)
|
|
|
369 |
}
|
|
|
370 |
|
|
|
371 |
}
|
|
|
372 |
case r => r
|
|
|
373 |
}
|
|
|
374 |
}
|
|
|
375 |
def bders (s: List[Char], r: ARexp) : ARexp = s match {
|
|
|
376 |
case Nil => r
|
|
|
377 |
case c::s => bders(s, bder(c, r))
|
|
|
378 |
}
|
|
|
379 |
|
|
|
380 |
def flats(rs: List[ARexp]): List[ARexp] = rs match {
|
|
|
381 |
case Nil => Nil
|
|
|
382 |
case AZERO :: rs1 => flats(rs1)
|
|
|
383 |
case AALTS(bs, rs1) :: rs2 => rs1.map(fuse(bs, _)) ::: flats(rs2)
|
|
|
384 |
case r1 :: rs2 => r1 :: flats(rs2)
|
|
|
385 |
}
|
|
|
386 |
|
|
|
387 |
def distinctBy[B, C](xs: List[B], f: B => C, acc: List[C] = Nil): List[B] = xs match {
|
|
|
388 |
case Nil => Nil
|
|
|
389 |
case (x::xs) => {
|
|
|
390 |
val res = f(x)
|
|
|
391 |
if (acc.contains(res)) distinctBy(xs, f, acc)
|
|
|
392 |
else x::distinctBy(xs, f, res::acc)
|
|
|
393 |
}
|
|
|
394 |
}
|
|
|
395 |
|
|
|
396 |
def prettyRexp(r: Rexp) : String = r match {
|
|
|
397 |
case STAR(r0) => s"${prettyRexp(r0)}*"
|
|
|
398 |
case SEQ(CHAR(c), r2) => c.toString ++ prettyRexp(r2)
|
|
|
399 |
case SEQ(r1, r2) => s"${prettyRexp(r1)}~${prettyRexp(r2)}"
|
|
|
400 |
case CHAR(c) => c.toString
|
|
|
401 |
case ANYCHAR => "."
|
|
|
402 |
// case NOT(r0) => s
|
|
|
403 |
}
|
|
|
404 |
|
|
|
405 |
def decode_aux(r: Rexp, bs: Bits) : (Val, Bits) = (r, bs) match {
|
|
|
406 |
case (ONE, bs) => (Empty, bs)
|
|
|
407 |
case (CHAR(f), bs) => (Chr(f), bs)
|
|
|
408 |
case (ALTS(r1, r2), Z::bs1) => {
|
|
|
409 |
val (v, bs2) = decode_aux(r1, bs1)
|
|
|
410 |
(Left(v), bs2)
|
|
|
411 |
}
|
|
|
412 |
case (ALTS(r1, r2), S::bs1) => {
|
|
|
413 |
val (v, bs2) = decode_aux(r2, bs1)
|
|
|
414 |
(Right(v), bs2)
|
|
|
415 |
}
|
|
|
416 |
case (SEQ(r1, r2), bs) => {
|
|
|
417 |
val (v1, bs1) = decode_aux(r1, bs)
|
|
|
418 |
val (v2, bs2) = decode_aux(r2, bs1)
|
|
|
419 |
(Sequ(v1, v2), bs2)
|
|
|
420 |
}
|
|
|
421 |
case (STAR(r1), S::bs) => {
|
|
|
422 |
val (v, bs1) = decode_aux(r1, bs)
|
|
|
423 |
//println(v)
|
|
|
424 |
val (Stars(vs), bs2) = decode_aux(STAR(r1), bs1)
|
|
|
425 |
(Stars(v::vs), bs2)
|
|
|
426 |
}
|
|
|
427 |
case (STAR(_), Z::bs) => (Stars(Nil), bs)
|
|
|
428 |
case (RECD(x, r1), bs) => {
|
|
|
429 |
val (v, bs1) = decode_aux(r1, bs)
|
|
|
430 |
(Rec(x, v), bs1)
|
|
|
431 |
}
|
|
|
432 |
case (NOT(r), bs) => (Nots(prettyRexp(r)), bs)
|
|
|
433 |
}
|
|
|
434 |
|
|
|
435 |
def decode(r: Rexp, bs: Bits) = decode_aux(r, bs) match {
|
|
|
436 |
case (v, Nil) => v
|
|
|
437 |
case _ => throw new Exception("Not decodable")
|
|
|
438 |
}
|
|
|
439 |
|
|
|
440 |
|
|
|
441 |
|
|
|
442 |
def blexSimp(r: Rexp, s: String) : List[Bit] = {
|
|
|
443 |
blex_simp(internalise(r), s.toList)
|
|
|
444 |
}
|
|
|
445 |
|
|
|
446 |
def blexing_simp(r: Rexp, s: String) : Val = {
|
|
|
447 |
val bit_code = blex_simp(internalise(r), s.toList)
|
|
|
448 |
decode(r, bit_code)
|
|
|
449 |
}
|
|
|
450 |
|
|
|
451 |
|
|
|
452 |
|
|
|
453 |
def bders_simp(s: List[Char], r: ARexp) : ARexp = s match {
|
|
|
454 |
case Nil => r
|
|
|
455 |
case c::s => bders_simp(s, bsimp(bder(c, r)))
|
|
|
456 |
}
|
|
|
457 |
|
|
|
458 |
def bdersSimp(s: String, r: Rexp) : ARexp = bders_simp(s.toList, internalise(r))
|
|
|
459 |
|
|
|
460 |
|
|
|
461 |
def erase(r:ARexp): Rexp = r match{
|
|
|
462 |
case AZERO => ZERO
|
|
|
463 |
case AONE(_) => ONE
|
|
|
464 |
case ACHAR(bs, c) => CHAR(c)
|
|
|
465 |
case AALTS(bs, Nil) => ZERO
|
|
|
466 |
case AALTS(bs, a::Nil) => erase(a)
|
|
|
467 |
case AALTS(bs, a::as) => ALTS(erase(a), erase(AALTS(bs, as)))
|
|
|
468 |
case ASEQ(bs, r1, r2) => SEQ (erase(r1), erase(r2))
|
|
|
469 |
case ASTAR(cs, r)=> STAR(erase(r))
|
|
|
470 |
case ANOT(bs, r) => NOT(erase(r))
|
|
|
471 |
case AANYCHAR(bs) => ANYCHAR
|
|
|
472 |
}
|
|
|
473 |
|
|
|
474 |
def breakHead(r: ARexp) : List[ARexp] = r match {
|
|
|
475 |
case AALTS(bs, rs) => rs
|
|
|
476 |
case r => r::Nil
|
|
|
477 |
}
|
|
|
478 |
|
|
|
479 |
def distinctByWithAcc[B, C](xs: List[B], f: B => C,
|
|
|
480 |
acc: List[C] = Nil, accB: List[B] = Nil): (List[B], List[C]) = xs match {
|
|
|
481 |
case Nil => (accB.reverse, acc)
|
|
|
482 |
case (x::xs) => {
|
|
|
483 |
val res = f(x)
|
|
|
484 |
if (acc.contains(res)) distinctByWithAcc(xs, f, acc, accB)
|
|
|
485 |
else distinctByWithAcc(xs, f, res::acc, x::accB)
|
|
|
486 |
}
|
|
|
487 |
}
|
|
|
488 |
|
|
|
489 |
|
|
|
490 |
def strongDistinctBy(xs: List[ARexp],
|
|
|
491 |
acc1: List[Rexp] = Nil,
|
|
|
492 |
acc2 : List[(List[Rexp], Rexp)] = Nil): List[ARexp] = xs match {
|
|
|
493 |
case Nil => Nil
|
|
|
494 |
case (x::xs) =>
|
|
|
495 |
if(acc1.contains(erase(x)))
|
|
|
496 |
strongDistinctBy(xs, acc1, acc2)
|
|
|
497 |
else{
|
|
|
498 |
x match {
|
|
|
499 |
case ASTAR(bs0, r0) =>
|
|
|
500 |
val headList : List[ARexp] = List[ARexp](AONE(Nil))
|
|
|
501 |
val i = acc2.indexWhere(
|
|
|
502 |
r2stl => {val (r2s, tl) = r2stl; tl == erase(r0) }
|
|
|
503 |
)
|
|
|
504 |
if(i == -1){
|
|
|
505 |
x::strongDistinctBy(
|
|
|
506 |
xs, erase(x)::acc1, (ONE::Nil, erase(r0))::acc2
|
|
|
507 |
)
|
|
|
508 |
}
|
|
|
509 |
else{
|
|
|
510 |
val headListAlready = acc2(i)
|
|
|
511 |
val (newHeads, oldHeadsUpdated) =
|
|
|
512 |
distinctByWithAcc(headList, erase, headListAlready._1)
|
|
|
513 |
newHeads match{
|
|
|
514 |
case newHead::Nil =>
|
|
|
515 |
ASTAR(bs0, r0) ::
|
|
|
516 |
strongDistinctBy(xs, erase(x)::acc1,
|
|
|
517 |
acc2.updated(i, (oldHeadsUpdated, headListAlready._2)) )//TODO: acc2 already contains headListAlready
|
|
|
518 |
case Nil =>
|
|
|
519 |
strongDistinctBy(xs, erase(x)::acc1,
|
|
|
520 |
acc2)
|
|
|
521 |
}
|
|
|
522 |
}
|
|
|
523 |
case ASEQ(bs, r1, ASTAR(bs0, r0)) =>
|
|
|
524 |
val headList = breakHead(r1)
|
|
|
525 |
val i = acc2.indexWhere(
|
|
|
526 |
r2stl => {val (r2s, tl) = r2stl; tl == erase(r0) }
|
|
|
527 |
)
|
|
|
528 |
if(i == -1){
|
|
|
529 |
x::strongDistinctBy(
|
|
|
530 |
xs, erase(x)::acc1, (headList.map(erase(_)), erase(r0))::acc2
|
|
|
531 |
)
|
|
|
532 |
}
|
|
|
533 |
else{
|
|
|
534 |
val headListAlready = acc2(i)
|
|
|
535 |
val (newHeads, oldHeadsUpdated) =
|
|
|
536 |
distinctByWithAcc(headList, erase, headListAlready._1)
|
|
|
537 |
newHeads match{
|
|
|
538 |
case newHead::Nil =>
|
|
|
539 |
ASEQ(bs, newHead, ASTAR(bs0, r0)) ::
|
|
|
540 |
strongDistinctBy(xs, erase(x)::acc1,
|
|
|
541 |
acc2.updated(i, (oldHeadsUpdated, headListAlready._2)) )//TODO: acc2 already contains headListAlready
|
|
|
542 |
case Nil =>
|
|
|
543 |
strongDistinctBy(xs, erase(x)::acc1,
|
|
|
544 |
acc2)
|
|
|
545 |
case hds => val AALTS(bsp, rsp) = r1
|
|
|
546 |
ASEQ(bs, AALTS(bsp, hds), ASTAR(bs0, r0)) ::
|
|
|
547 |
strongDistinctBy(xs, erase(x)::acc1,
|
|
|
548 |
acc2.updated(i, (oldHeadsUpdated, headListAlready._2)))
|
|
|
549 |
}
|
|
|
550 |
}
|
|
|
551 |
case rPrime => x::strongDistinctBy(xs, erase(x)::acc1, acc2)
|
|
|
552 |
}
|
|
|
553 |
|
|
|
554 |
}
|
|
|
555 |
|
|
|
556 |
}
|
|
|
557 |
|
|
|
558 |
|
|
|
559 |
def blex_simp(r: ARexp, s: List[Char]) : Bits = s match {
|
|
|
560 |
case Nil => {
|
|
|
561 |
if (bnullable(r)) {
|
|
|
562 |
//println(asize(r))
|
|
|
563 |
val bits = mkepsBC(r)
|
|
|
564 |
bits
|
|
|
565 |
}
|
|
|
566 |
else throw new Exception("Not matched")
|
|
|
567 |
}
|
|
|
568 |
case c::cs => {
|
|
|
569 |
val der_res = bder(c,r)
|
|
|
570 |
val simp_res = bsimp(der_res)
|
|
|
571 |
blex_simp(simp_res, cs)
|
|
|
572 |
}
|
|
|
573 |
}
|
|
|
574 |
def size(r: Rexp) : Int = r match {
|
|
|
575 |
case ZERO => 1
|
|
|
576 |
case ONE => 1
|
|
|
577 |
case CHAR(_) => 1
|
|
|
578 |
case ANYCHAR => 1
|
|
|
579 |
case NOT(r0) => 1 + size(r0)
|
|
|
580 |
case SEQ(r1, r2) => 1 + size(r1) + size(r2)
|
|
|
581 |
case ALTS(r1, r2) => 1 + List(r1, r2).map(size).sum
|
|
|
582 |
case STAR(r) => 1 + size(r)
|
|
|
583 |
}
|
|
|
584 |
|
|
|
585 |
def asize(a: ARexp) = size(erase(a))
|
|
|
586 |
|
|
|
587 |
|
|
|
588 |
// @arg(doc = "small tests")
|
|
|
589 |
val STARREG = ("a" | "aa").%
|
|
|
590 |
|
|
|
591 |
@main
|
|
|
592 |
def small() = {
|
|
|
593 |
|
|
|
594 |
val prog0 = """aaa"""
|
|
|
595 |
println(s"test: $prog0")
|
|
|
596 |
// println(lexing_simp(NOTREG, prog0))
|
|
|
597 |
// val v = lex_simp(NOTREG, prog0.toList)
|
|
|
598 |
// println(v)
|
|
|
599 |
|
|
|
600 |
// val d = (lex_simp(NOTREG, prog0.toList))
|
|
|
601 |
// println(d)
|
|
|
602 |
|
|
|
603 |
val bd = bdersSimp(prog0, STARREG)
|
|
|
604 |
println(erase(bd))
|
|
|
605 |
println(asize(bd))
|
|
|
606 |
|
|
|
607 |
val vres = blexing_simp( STARREG, prog0)
|
|
|
608 |
println(vres)
|
|
|
609 |
// println(vs.length)
|
|
|
610 |
// println(vs)
|
|
|
611 |
|
|
|
612 |
|
|
|
613 |
// val prog1 = """read n; write n"""
|
|
|
614 |
// println(s"test: $prog1")
|
|
|
615 |
// println(lexing_simp(WHILE_REGS, prog1))
|
|
|
616 |
}
|
|
|
617 |
|
|
|
618 |
// // Bigger Tests
|
|
|
619 |
// //==============
|
|
|
620 |
|
|
|
621 |
// // escapes strings and prints them out as "", "\n" and so on
|
|
|
622 |
// def esc(raw: String): String = {
|
|
|
623 |
// import scala.reflect.runtime.universe._
|
|
|
624 |
// Literal(Constant(raw)).toString
|
|
|
625 |
// }
|
|
|
626 |
|
|
|
627 |
// def escape(tks: List[(String, String)]) =
|
|
|
628 |
// tks.map{ case (s1, s2) => (s1, esc(s2))}
|
|
|
629 |
|
|
|
630 |
|
|
|
631 |
// val prog2 = """
|
|
|
632 |
// write "Fib";
|
|
|
633 |
// read n;
|
|
|
634 |
// minus1 := 0;
|
|
|
635 |
// minus2 := 1;
|
|
|
636 |
// while n > 0 do {
|
|
|
637 |
// temp := minus2;
|
|
|
638 |
// minus2 := minus1 + minus2;
|
|
|
639 |
// minus1 := temp;
|
|
|
640 |
// n := n - 1
|
|
|
641 |
// };
|
|
|
642 |
// write "Result";
|
|
|
643 |
// write minus2
|
|
|
644 |
// """
|
|
|
645 |
|
|
|
646 |
// @arg(doc = "Fibonacci test")
|
|
|
647 |
// @main
|
|
|
648 |
// def fib() = {
|
|
|
649 |
// println("lexing fib program")
|
|
|
650 |
// println(escape(lexing_simp(WHILE_REGS, prog2)).mkString("\n"))
|
|
|
651 |
// }
|
|
|
652 |
|
|
|
653 |
|
|
|
654 |
// val prog3 = """
|
|
|
655 |
// start := 1000;
|
|
|
656 |
// x := start;
|
|
|
657 |
// y := start;
|
|
|
658 |
// z := start;
|
|
|
659 |
// while 0 < x do {
|
|
|
660 |
// while 0 < y do {
|
|
|
661 |
// while 0 < z do {
|
|
|
662 |
// z := z - 1
|
|
|
663 |
// };
|
|
|
664 |
// z := start;
|
|
|
665 |
// y := y - 1
|
|
|
666 |
// };
|
|
|
667 |
// y := start;
|
|
|
668 |
// x := x - 1
|
|
|
669 |
// }
|
|
|
670 |
// """
|
|
|
671 |
|
|
|
672 |
// @arg(doc = "Loops test")
|
|
|
673 |
// @main
|
|
|
674 |
// def loops() = {
|
|
|
675 |
// println("lexing Loops")
|
|
|
676 |
// println(escape(lexing_simp(WHILE_REGS, prog3)).mkString("\n"))
|
|
|
677 |
// }
|
|
|
678 |
|
|
|
679 |
// @arg(doc = "Email Test")
|
|
|
680 |
// @main
|
|
|
681 |
// def email() = {
|
|
|
682 |
// val lower = "abcdefghijklmnopqrstuvwxyz"
|
|
|
683 |
|
|
|
684 |
// val NAME = RECD("name", PLUS(RANGE(lower ++ "_.-")))
|
|
|
685 |
// val DOMAIN = RECD("domain", PLUS(RANGE(lower ++ "-")))
|
|
|
686 |
// val RE = RANGE(lower ++ ".")
|
|
|
687 |
// val TOPLEVEL = RECD("top", (RE ~ RE) |
|
|
|
688 |
// (RE ~ RE ~ RE) |
|
|
|
689 |
// (RE ~ RE ~ RE ~ RE) |
|
|
|
690 |
// (RE ~ RE ~ RE ~ RE ~ RE) |
|
|
|
691 |
// (RE ~ RE ~ RE ~ RE ~ RE ~ RE))
|
|
|
692 |
|
|
|
693 |
// val EMAIL = NAME ~ "@" ~ DOMAIN ~ "." ~ TOPLEVEL
|
|
|
694 |
|
|
|
695 |
// println(lexing_simp(EMAIL, "christian.urban@kcl.ac.uk"))
|
|
|
696 |
// }
|
|
|
697 |
|
|
|
698 |
|
|
|
699 |
// @arg(doc = "All tests.")
|
|
|
700 |
// @main
|
|
|
701 |
// def all() = { small(); fib() ; loops() ; email() }
|
|
|
702 |
|
|
|
703 |
|
|
|
704 |
|
|
|
705 |
|
|
|
706 |
// runs with amm2 and amm3
|
|
|
707 |
|
|
|
708 |
|
|
|
709 |
|