--- a/progs/comb1.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,226 +0,0 @@
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-/* Note, in the lectures I did not show the implicit type
- * constraint IsSeq, which means that the input type 'I' needs
- * to be a sequence. */
-
-type IsSeq[A] = A => Seq[_]
-
-abstract class Parser[I : IsSeq, T] {
- def parse(ts: I): Set[(T, I)]
-
- def parse_all(ts: I) : Set[T] =
- for ((head, tail) <- parse(ts);
- if tail.isEmpty) yield head
-}
-
-class SeqParser[I : IsSeq, T, S](p: => Parser[I, T],
- q: => Parser[I, S]) extends Parser[I, (T, S)] {
- def parse(sb: I) =
- for ((head1, tail1) <- p.parse(sb);
- (head2, tail2) <- q.parse(tail1)) yield ((head1, head2), tail2)
-}
-
-class AltParser[I : IsSeq, T](p: => Parser[I, T],
- q: => Parser[I, T]) extends Parser[I, T] {
- def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
-}
-
-class FunParser[I : IsSeq, T, S](p: => Parser[I, T],
- f: T => S) extends Parser[I, S] {
- def parse(sb: I) =
- for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-// atomic parsers for characters, numbers and strings
-case class CharParser(c: Char) extends Parser[String, Char] {
- def parse(sb: String) =
- if (sb != "" && sb.head == c) Set((c, sb.tail)) else Set()
-}
-
-import scala.util.matching.Regex
-case class RegexParser(reg: Regex) extends Parser[String, String] {
- def parse(sb: String) = reg.findPrefixMatchOf(sb) match {
- case None => Set()
- case Some(m) => Set((m.matched, m.after.toString))
- }
-}
-
-val NumParser = RegexParser("[0-9]+".r)
-def StringParser(s: String) = RegexParser(Regex.quote(s).r)
-
-// NumParserInt2 transforms a "string integer" into an actual Int;
-// needs new, because FunParser is not a case class
-val NumParserInt2 = new FunParser(NumParser, (s: String) => s.toInt)
-
-
-// convenience
-implicit def string2parser(s: String) = StringParser(s)
-implicit def char2parser(c: Char) = CharParser(c)
-
-implicit def ParserOps[I, T](p: Parser[I, T])(implicit ev: I => Seq[_]) = new {
- def ||(q : => Parser[I, T]) = new AltParser[I, T](p, q)
- def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
- def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-}
-
-implicit def StringOps(s: String) = new {
- def ||(q : => Parser[String, String]) = new AltParser[String, String](s, q)
- def ||(r: String) = new AltParser[String, String](s, r)
- def ==>[S] (f: => String => S) = new FunParser[String, String, S](s, f)
- def ~[S](q : => Parser[String, S]) =
- new SeqParser[String, String, S](s, q)
- def ~(r: String) =
- new SeqParser[String, String, String](s, r)
-}
-
-// NumParserInt can now be written as _ ===> _
-// the first part is the parser, and the second the
-// semantic action
-val NumParserInt = NumParser ==> (s => s.toInt)
-
-
-// palindromes
-lazy val Pal : Parser[String, String] =
- (("a" ~ Pal ~ "a") ==> { case ((x, y), z) => x + y + z } ||
- ("b" ~ Pal ~ "b") ==> { case ((x, y), z) => x + y + z } || "a" || "b" || "")
-
-Pal.parse_all("abaaaba")
-Pal.parse_all("abacba")
-Pal.parse("abaaaba")
-
-println("Palindrome: " + Pal.parse_all("abaaaba"))
-
-// parser for well-nested parentheses (transforms '(' -> '{' , ')' -> '}' )
-lazy val P : Parser[String, String] =
- "(" ~ P ~ ")" ~ P ==> { case (((_, x), _), y) => "{" + x + "}" + y } || ""
-
-P.parse_all("(((()()))())")
-P.parse_all("(((()()))()))")
-P.parse_all(")(")
-P.parse_all("()")
-
-// just counts parentheses
-lazy val P2 : Parser[String, Int] =
- ("(" ~ P2 ~ ")" ~ P2 ==> { case (((_, x), _), y) => x + y + 2 } ||
- "" ==> { _ => 0 })
-
-P2.parse_all("(((()()))())")
-P2.parse_all("(((()()))()))")
-
-// counts opening and closing parentheses
-lazy val P3 : Parser[String, Int] =
- ("(" ~ P3 ==> { case (_, x) => x + 1 } ||
- ")" ~ P3 ==> { case (_, x) => x - 1 } ||
- "" ==> { _ => 0 })
-
-P3.parse_all("(((()()))())")
-P3.parse_all("(((()()))()))")
-P3.parse_all(")(")
-
-// Arithmetic Expressions (Terms and Factors)
-// (because it is mutually recursive, you need :paste
-// for munching this definition in the REPL)
-
-lazy val E: Parser[String, Int] =
- (T ~ "+" ~ E) ==> { case ((x, y), z) => x + z } ||
- (T ~ "-" ~ E) ==> { case ((x, y), z) => x - z } || T
-lazy val T: Parser[String, Int] =
- (F ~ "*" ~ T) ==> { case ((x, y), z) => x * z } || F
-lazy val F: Parser[String, Int] =
- ("(" ~ E ~ ")") ==> { case ((x, y), z) => y } || NumParserInt
-
-println(E.parse_all("1+3+4"))
-println(E.parse("1+3+4"))
-println(E.parse_all("4*2+3"))
-println(E.parse_all("4*(2+3)"))
-println(E.parse_all("(4)*((2+3))"))
-println(E.parse_all("4/2+3"))
-println(E.parse("1 + 2 * 3"))
-println(E.parse_all("(1+2)+3"))
-println(E.parse_all("1+2+3"))
-
-/* same parser but producing a string
-lazy val E: Parser[String, String] =
- (T ~ "+" ~ E) ==> { case ((x, y), z) => "(" + x + ")+(" + z + ")"} || T
-lazy val T: Parser[String, String] =
- (F ~ "*" ~ T) ==> { case ((x, y), z) => "(" + x + ")*("+ z + ")"} || F
-lazy val F: Parser[String, String] =
- ("(" ~ E ~ ")") ==> { case ((x, y), z) => y } || NumParser
-*/
-
-// no left-recursion allowed, otherwise will loop
-lazy val EL: Parser[String, Int] =
- (EL ~ "+" ~ EL ==> { case ((x, y), z) => x + z} ||
- EL ~ "*" ~ EL ==> { case ((x, y), z) => x * z} ||
- "(" ~ EL ~ ")" ==> { case ((x, y), z) => y} ||
- NumParserInt)
-
-//println(EL.parse_all("1+2+3"))
-
-
-// non-ambiguous vs ambiguous grammars
-
-// ambiguous
-lazy val S : Parser[String, String] =
- ("1" ~ S ~ S ~ S) ==> { case (((x, y), z), v) => x + y + z } || ""
-
-S.parse("1" * 10)
-
-// non-ambiguous
-lazy val U : Parser[String, String] =
- ("1" ~ U) ==> { case (x, y) => x + y } || ""
-
-U.parse("1" * 25)
-
-U.parse("11")
-U.parse("11111")
-U.parse("11011")
-
-U.parse_all("1" * 100)
-U.parse_all("1" * 100 + "0")
-
-lazy val UCount : Parser[String, Int] =
- ("1" ~ UCount) ==> { case (x, y) => y + 1 } || "" ==> { x => 0 }
-
-UCount.parse("11111")
-UCount.parse_all("11111")
-
-
-
-// Single Character parser
-lazy val One : Parser[String, String] = "1"
-lazy val Two : Parser[String, String] = "2"
-
-One.parse("1")
-One.parse("111")
-
-(One ~ One).parse("111")
-(One ~ One ~ One).parse("1111")
-(One ~ One ~ One ~ One).parse("1111")
-
-(One || Two).parse("111")
-
-
-// a problem with the arithmetic expression parser -> gets
-// slow with deeply nested parentheses
-E.parse("1")
-E.parse("(1)")
-E.parse("((1))")
-E.parse("(((1)))")
-E.parse("((((1))))")
-E.parse("((((((1))))))")
-E.parse("(((((((1)))))))")
-
-
-
-
-/*
-
-starting symbols
-tokenise/detokenise
-:paste
-pairs in sequences
-
-*/
\ No newline at end of file
--- a/progs/comb1a.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,203 +0,0 @@
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-// more convenience for the semantic actions later on
-case class ~[+A, +B](_1: A, _2: B)
-
-
-/* Note, in the lectures I did not show the implicit type consraint
- * I => Seq[_], which means that the input type 'I' needs to be
- * a sequence. */
-
-type IsSeq[A] = A => Seq[_]
-
-abstract class Parser[I : IsSeq, T] {
- def parse(ts: I): Set[(T, I)]
-
- def parse_all(ts: I) : Set[T] =
- for ((head, tail) <- parse(ts);
- if tail.isEmpty) yield head
-}
-
-
-class SeqParser[I : IsSeq, T, S](p: => Parser[I, T],
- q: => Parser[I, S]) extends Parser[I, ~[T, S]] {
- def parse(sb: I) =
- for ((head1, tail1) <- p.parse(sb);
- (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
-}
-
-class AltParser[I : IsSeq, T](p: => Parser[I, T],
- q: => Parser[I, T]) extends Parser[I, T] {
- def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
-}
-
-class FunParser[I : IsSeq, T, S](p: => Parser[I, T],
- f: T => S) extends Parser[I, S] {
- def parse(sb: I) =
- for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-// atomic parsers for characters, numbers and strings
-case class CharParser(c: Char) extends Parser[String, Char] {
- def parse(sb: String) =
- if (sb != "" && sb.head == c) Set((c, sb.tail)) else Set()
-}
-
-import scala.util.matching.Regex
-case class RegexParser(reg: Regex) extends Parser[String, String] {
- def parse(sb: String) = reg.findPrefixMatchOf(sb) match {
- case None => Set()
- case Some(m) => Set((m.matched, m.after.toString))
- }
-}
-
-val NumParser = RegexParser("[0-9]+".r)
-def StringParser(s: String) = RegexParser(Regex.quote(s).r)
-
-// NumParserInt2 transforms a "string integer" into an Int;
-// needs new, because FunParser is not a case class
-
-val NumParserInt2 = new FunParser(NumParser, (s: String) => s.toInt)
-
-
-// convenience
-implicit def string2parser(s: String) = StringParser(s)
-implicit def char2parser(c: Char) = CharParser(c)
-
-implicit def ParserOps[I : IsSeq, T](p: Parser[I, T]) = new {
- def ||(q : => Parser[I, T]) = new AltParser[I, T](p, q)
- def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
- def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-}
-
-implicit def StringOps(s: String) = new {
- def ||(q : => Parser[String, String]) = new AltParser[String, String](s, q)
- def ||(r: String) = new AltParser[String, String](s, r)
- def ==>[S] (f: => String => S) = new FunParser[String, String, S](s, f)
- def ~[S](q : => Parser[String, S]) =
- new SeqParser[String, String, S](s, q)
- def ~(r: String) =
- new SeqParser[String, String, String](s, r)
-}
-
-// NumParserInt can now be written as
-val NumParserInt = NumParser ==> (s => s.toInt)
-
-
-lazy val Pal : Parser[String, String] =
- (("a" ~ Pal ~ "a") ==> { case x ~ y ~ z => x + y + z } ||
- ("b" ~ Pal ~ "b") ==> { case x ~ y ~ z => x + y + z } || "a" || "b" || "")
-
-Pal.parse_all("abaaaba")
-Pal.parse("abaaaba")
-
-println("Palindrome: " + Pal.parse_all("abaaaba"))
-
-// well-nested parentheses parser (transforms '(' -> '{' , ')' -> '}' )
-lazy val P : Parser[String, String] =
- "(" ~ P ~ ")" ~ P ==> { case _ ~ x ~ _ ~ y => "{" + x + "}" + y } || ""
-
-P.parse_all("(((()()))())")
-P.parse_all("(((()()))()))")
-P.parse_all(")(")
-P.parse_all("()")
-
-// Arithmetic Expressions (Terms and Factors)
-
-lazy val E: Parser[String, Int] =
- (T ~ "+" ~ E) ==> { case x ~ _ ~ z => x + z } ||
- (T ~ "-" ~ E) ==> { case x ~ _ ~ z => x - z } || T
-lazy val T: Parser[String, Int] =
- (F ~ "*" ~ T) ==> { case x ~ _ ~ z => x * z } || F
-lazy val F: Parser[String, Int] =
- ("(" ~ E ~ ")") ==> { case _ ~ y ~ _ => y } || NumParserInt
-
-/* same parser but producing a string
-lazy val E: Parser[String, String] =
- (T ~ "+" ~ E) ==> { case x ~ y ~ z => "(" + x + ")+(" + z + ")"} || T
-lazy val T: Parser[String, String] =
- (F ~ "*" ~ T) ==> { case x ~ y ~ z => "(" + x + ")*("+ z + ")"} || F
-lazy val F: Parser[String, String] =
- ("(" ~ E ~ ")") ==> { case x ~ y ~ z => y } || NumParser
-*/
-
-println(E.parse_all("1+3+4"))
-println(E.parse("1+3+4"))
-println(E.parse_all("4*2+3"))
-println(E.parse_all("4*(2+3)"))
-println(E.parse_all("(4)*((2+3))"))
-println(E.parse_all("4/2+3"))
-println(E.parse("1 + 2 * 3"))
-println(E.parse_all("(1+2)+3"))
-println(E.parse_all("1+2+3"))
-
-
-
-// no left-recursion allowed, otherwise will loop
-lazy val EL: Parser[String, Int] =
- (EL ~ "+" ~ EL ==> { case x ~ y ~ z => x + z} ||
- EL ~ "*" ~ EL ==> { case x ~ y ~ z => x * z} ||
- "(" ~ EL ~ ")" ==> { case x ~ y ~ z => y} ||
- NumParserInt)
-
-//println(EL.parse_all("1+2+3"))
-
-
-
-
-// non-ambiguous vs ambiguous grammars
-
-// ambiguous
-lazy val S : Parser[String, String] =
- ("1" ~ S ~ S) ==> { case x ~ y ~ z => x + y + z } || ""
-
-S.parse("1" * 10)
-
-// non-ambiguous
-lazy val U : Parser[String, String] =
- ("1" ~ U) ==> { case x ~ y => x + y } || ""
-
-U.parse("1" * 25)
-
-U.parse("11")
-U.parse("11111")
-U.parse("11011")
-
-U.parse_all("1" * 100)
-U.parse_all("1" * 100 + "0")
-
-lazy val UCount : Parser[String, Int] =
- ("1" ~ UCount) ==> { case x ~ y => y + 1 } || "" ==> { x => 0 }
-
-UCount.parse("11111")
-UCount.parse_all("11111")
-
-
-
-// Single Character parser
-lazy val One : Parser[String, String] = "1"
-lazy val Two : Parser[String, String] = "2"
-
-One.parse("1")
-One.parse("111")
-
-(One ~ One).parse("111")
-(One ~ One ~ One).parse("111")
-(One ~ One ~ One ~ One).parse("1111")
-
-(One || Two).parse("111")
-
-
-
-// a problem with the arithmetic expression parser -> gets
-// slow with deeply nested parentheses
-println("Runtime problem")
-E.parse("1")
-E.parse("(1)")
-E.parse("((1))")
-E.parse("(((1)))")
-E.parse("((((1))))")
-E.parse("((((((1))))))")
-E.parse("(((((((1)))))))")
-E.parse("((((((((1)))))))")
--- a/progs/comb2.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,245 +0,0 @@
-// A parser and interpreter for the While language
-//
-
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-// more convenience for the semantic actions later on
-case class ~[+A, +B](_1: A, _2: B)
-
-
-type IsSeq[A] = A => Seq[_]
-
-abstract class Parser[I : IsSeq, T] {
- def parse(ts: I): Set[(T, I)]
-
- def parse_all(ts: I) : Set[T] =
- for ((head, tail) <- parse(ts); if tail.isEmpty) yield head
-}
-
-class SeqParser[I : IsSeq, T, S](p: => Parser[I, T], q: => Parser[I, S]) extends Parser[I, ~[T, S]] {
- def parse(sb: I) =
- for ((head1, tail1) <- p.parse(sb);
- (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
-}
-
-class AltParser[I : IsSeq, T](p: => Parser[I, T], q: => Parser[I, T]) extends Parser[I, T] {
- def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
-}
-
-class FunParser[I : IsSeq, T, S](p: => Parser[I, T], f: T => S) extends Parser[I, S] {
- def parse(sb: I) =
- for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-case class StringParser(s: String) extends Parser[String, String] {
- def parse(sb: String) = {
- val (prefix, suffix) = sb.splitAt(s.length)
- if (prefix == s) Set((prefix, suffix)) else Set()
- }
-}
-
-case object NumParser extends Parser[String, Int] {
- val reg = "[0-9]+".r
- def parse(sb: String) = reg.findPrefixOf(sb) match {
- case None => Set()
- case Some(s) => {
- val (head, tail) = sb.splitAt(s.length)
- Set((head.toInt, tail))
- }
- }
-}
-
-
-implicit def string2parser(s : String) = StringParser(s)
-
-implicit def ParserOps[I : IsSeq, T](p: Parser[I, T]) = new {
- def ||(q : => Parser[I, T]) = new AltParser[I, T](p, q)
- def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
- def ~[S](q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-}
-
-implicit def StringOps(s: String) = new {
- def ||(q : => Parser[String, String]) = new AltParser[String, String](s, q)
- def ||(r: String) = new AltParser[String, String](s, r)
- def ==>[S] (f: => String => S) = new FunParser[String, String, S](s, f)
- def ~[S](q : => Parser[String, S]) =
- new SeqParser[String, String, S](s, q)
- def ~(r: String) =
- new SeqParser[String, String, String](s, r)
-}
-
-
-// the abstract syntax trees for the WHILE language
-abstract class Stmt
-abstract class AExp
-abstract class BExp
-
-type Block = List[Stmt]
-
-case object Skip extends Stmt
-case class If(a: BExp, bl1: Block, bl2: Block) extends Stmt
-case class While(b: BExp, bl: Block) extends Stmt
-case class Assign(s: String, a: AExp) extends Stmt
-case class Write(s: String) extends Stmt
-
-
-case class Var(s: String) extends AExp
-case class Num(i: Int) extends AExp
-case class Aop(o: String, a1: AExp, a2: AExp) extends AExp
-
-case object True extends BExp
-case object False extends BExp
-case class Bop(o: String, a1: AExp, a2: AExp) extends BExp
-case class And(b1: BExp, b2: BExp) extends BExp
-case class Or(b1: BExp, b2: BExp) extends BExp
-
-case object IdParser extends Parser[String, String] {
- val reg = "[a-z][a-z,0-9]*".r
- def parse(sb: String) = reg.findPrefixOf(sb) match {
- case None => Set()
- case Some(s) => Set(sb.splitAt(s.length))
- }
-}
-
-// arithmetic expressions
-lazy val AExp: Parser[String, AExp] =
- (Te ~ "+" ~ AExp) ==> { case x ~ _ ~ z => Aop("+", x, z): AExp } ||
- (Te ~ "-" ~ AExp) ==> { case x ~ _ ~ z => Aop("-", x, z): AExp } || Te
-lazy val Te: Parser[String, AExp] =
- (Fa ~ "*" ~ Te) ==> { case x ~ _ ~ z => Aop("*", x, z): AExp } ||
- (Fa ~ "/" ~ Te) ==> { case x ~ _ ~ z => Aop("/", x, z): AExp } || Fa
-lazy val Fa: Parser[String, AExp] =
- ("(" ~ AExp ~ ")") ==> { case _ ~ y ~ _ => y } ||
- IdParser ==> Var ||
- NumParser ==> Num
-
-// boolean expressions with some simple nesting
-lazy val BExp: Parser[String, BExp] =
- (AExp ~ "==" ~ AExp) ==> { case x ~ _ ~ z => Bop("==", x, z): BExp } ||
- (AExp ~ "!=" ~ AExp) ==> { case x ~ _ ~ z => Bop("!=", x, z): BExp } ||
- (AExp ~ "<" ~ AExp) ==> { case x ~ _ ~ z => Bop("<", x, z): BExp } ||
- (AExp ~ ">" ~ AExp) ==> { case x ~ _ ~ z => Bop(">", x, z): BExp } ||
- ("(" ~ BExp ~ ")" ~ "&&" ~ BExp) ==> { case _ ~ y ~ _ ~ _ ~ v => And(y, v): BExp } ||
- ("(" ~ BExp ~ ")" ~ "||" ~ BExp) ==> { case _ ~ y ~ _ ~ _ ~ v => Or(y, v): BExp } ||
- ("true" ==> (_ => True: BExp )) ||
- ("false" ==> (_ => False: BExp )) ||
- ("(" ~ BExp ~ ")") ==> { case _ ~ x ~ _ => x }
-
-// statement / statements
-lazy val Stmt: Parser[String, Stmt] =
- (("skip" ==> (_ => Skip: Stmt)) ||
- (IdParser ~ ":=" ~ AExp) ==> { case x ~ _ ~ z => Assign(x, z): Stmt } ||
- ("write(" ~ IdParser ~ ")") ==> { case _ ~ y ~ _ => Write(y): Stmt } ||
- ("if" ~ BExp ~ "then" ~ Block ~ "else" ~ Block) ==>
- { case _ ~ y ~ _ ~ u ~ _ ~ w => If(y, u, w): Stmt } ||
- ("while" ~ BExp ~ "do" ~ Block) ==> { case _ ~ y ~ _ ~ w => While(y, w) })
-
-lazy val Stmts: Parser[String, Block] =
- (Stmt ~ ";" ~ Stmts) ==> { case x ~ _ ~ z => x :: z : Block } ||
- (Stmt ==> ( s => List(s) : Block))
-
-// blocks (enclosed in curly braces)
-lazy val Block: Parser[String, Block] =
- (("{" ~ Stmts ~ "}") ==> { case _ ~ y ~ _ => y } ||
- (Stmt ==> (s => List(s))))
-
-
-Stmts.parse_all("x2:=5+3;")
-Block.parse_all("{x:=5;y:=8}")
-Block.parse_all("if(false)then{x:=5}else{x:=10}")
-
-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""".replaceAll("\\s+", "")
-
-Stmts.parse_all(fib)
-
-
-// an interpreter for the WHILE language
-type Env = Map[String, Int]
-
-def eval_aexp(a: AExp, env: Env) : Int = a match {
- case Num(i) => i
- case Var(s) => env(s)
- case Aop("+", a1, a2) => eval_aexp(a1, env) + eval_aexp(a2, env)
- case Aop("-", a1, a2) => eval_aexp(a1, env) - eval_aexp(a2, env)
- case Aop("*", a1, a2) => eval_aexp(a1, env) * eval_aexp(a2, env)
- case Aop("/", a1, a2) => eval_aexp(a1, env) / eval_aexp(a2, env)
-}
-
-def eval_bexp(b: BExp, env: Env) : Boolean = b match {
- case True => true
- case False => false
- case Bop("==", a1, a2) => eval_aexp(a1, env) == eval_aexp(a2, env)
- case Bop("!=", a1, a2) => !(eval_aexp(a1, env) == eval_aexp(a2, env))
- case Bop(">", a1, a2) => eval_aexp(a1, env) > eval_aexp(a2, env)
- case Bop("<", a1, a2) => eval_aexp(a1, env) < eval_aexp(a2, env)
- case And(b1, b2) => eval_bexp(b1, env) && eval_bexp(b2, env)
- case Or(b1, b2) => eval_bexp(b1, env) || eval_bexp(b2, env)
-}
-
-def eval_stmt(s: Stmt, env: Env) : Env = s match {
- case Skip => env
- case Assign(x, a) => env + (x -> eval_aexp(a, env))
- case If(b, bl1, bl2) => if (eval_bexp(b, env)) eval_bl(bl1, env) else eval_bl(bl2, env)
- case While(b, bl) =>
- if (eval_bexp(b, env)) eval_stmt(While(b, bl), eval_bl(bl, env))
- else env
- case Write(x) => { println(env(x)) ; env }
-}
-
-def eval_bl(bl: Block, env: Env) : Env = bl match {
- case Nil => env
- case s::bl => eval_bl(bl, eval_stmt(s, env))
-}
-
-def eval(bl: Block) : Env = eval_bl(bl, Map())
-
-// parse + evaluate fib program; then lookup what is
-// stored under the variable result
-println(eval(Stmts.parse_all(fib).head)("result"))
-
-
-// more examles
-
-// calculate and print all factors bigger
-// than 1 and smaller than n
-println("Factors")
-
-val factors =
- """n := 12;
- f := 2;
- while (f < n / 2 + 1) do {
- if ((n / f) * f == n) then { write(f) } else { skip };
- f := f + 1
- }""".replaceAll("\\s+", "")
-
-eval(Stmts.parse_all(factors).head)
-
-// calculate all prime numbers up to a number
-println("Primes")
-
-val primes =
- """end := 100;
- n := 2;
- while (n < end) do {
- f := 2;
- tmp := 0;
- while ((f < n / 2 + 1) && (tmp == 0)) do {
- if ((n / f) * f == n) then { tmp := 1 } else { skip };
- f := f + 1
- };
- if (tmp == 0) then { write(n) } else { skip };
- n := n + 1
- }""".replaceAll("\\s+", "")
-
-eval(Stmts.parse_all(primes).head)
--- a/progs/fun-bare.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,187 +0,0 @@
-// A Small Compiler for a Simple Functional Language
-// (it does not include a parser and lexer)
-
-// abstract syntax trees
-abstract class Exp
-abstract class BExp
-abstract class Decl
-
-// functions and declarations
-case class Def(name: String, args: List[String], body: Exp) extends Decl
-case class Main(e: Exp) extends Decl
-
-// expressions
-case class Call(name: String, args: List[Exp]) extends Exp
-case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
-case class Write(e: Exp) extends Exp
-case class Var(s: String) extends Exp
-case class Num(i: Int) extends Exp
-case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
-case class Sequ(e1: Exp, e2: Exp) extends Exp
-
-// boolean expressions
-case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
-
-// calculating the maximal needed stack size
-def max_stack_exp(e: Exp): Int = e match {
- case Call(_, args) => args.map(max_stack_exp).sum
- case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
- case Write(e) => max_stack_exp(e) + 1
- case Var(_) => 1
- case Num(_) => 1
- case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
- case Sequ(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
-}
-def max_stack_bexp(e: BExp): Int = e match {
- case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
-}
-
-// compiler - built-in functions
-// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
-//
-
-val library = """
-.class public XXX.XXX
-.super java/lang/Object
-
-.method public static write(I)V
- .limit locals 5
- .limit stack 5
- iload 0
- getstatic java/lang/System/out Ljava/io/PrintStream;
- swap
- invokevirtual java/io/PrintStream/println(I)V
- return
-.end method
-
-"""
-
-// for generating new labels
-var counter = -1
-
-def Fresh(x: String) = {
- counter += 1
- x ++ "_" ++ counter.toString()
-}
-
-// convenient string interpolations for
-// generating instructions, labels etc
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-// convenience for code-generation (string interpolations)
-implicit def sring_inters(sc: StringContext) = new {
- def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n" // instructions
- def l(args: Any*): String = sc.s(args:_*) ++ ":\n" // labels
- def m(args: Any*): String = sc.s(args:_*) ++ "\n" // methods
-}
-
-// variable / index environments
-type Env = Map[String, Int]
-
-// compile expressions
-def compile_exp(a: Exp, env : Env) : String = a match {
- case Num(i) => i"ldc $i"
- case Var(s) => i"iload ${env(s)}"
- case Aop("+", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"iadd"
- case Aop("-", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"isub"
- case Aop("*", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"imul"
- case Aop("/", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"idiv"
- case Aop("%", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"irem"
- case If(b, a1, a2) => {
- val if_else = Fresh("If_else")
- val if_end = Fresh("If_end")
- compile_bexp(b, env, if_else) ++
- compile_exp(a1, env) ++
- i"goto $if_end" ++
- l"$if_else" ++
- compile_exp(a2, env) ++
- l"$if_end"
- }
- case Call(name, args) => {
- val is = "I" * args.length
- args.map(a => compile_exp(a, env)).mkString ++
- i"invokestatic XXX/XXX/$name($is)I"
- }
- case Sequ(a1, a2) => {
- compile_exp(a1, env) ++ i"pop" ++ compile_exp(a2, env)
- }
- case Write(a1) => {
- compile_exp(a1, env) ++
- i"dup" ++
- i"invokestatic XXX/XXX/write(I)V"
- }
-}
-
-// compile boolean expressions
-def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
- case Bop("==", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpne $jmp"
- case Bop("!=", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpeq $jmp"
- case Bop("<", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpge $jmp"
- case Bop("<=", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpgt $jmp"
-}
-
-// compile functions and declarations
-def compile_decl(d: Decl) : String = d match {
- case Def(name, args, a) => {
- val env = args.zipWithIndex.toMap
- val is = "I" * args.length
- m".method public static $name($is)I" ++
- m".limit locals ${args.length.toString}" ++
- m".limit stack ${1 + max_stack_exp(a)}" ++
- l"${name}_Start" ++
- compile_exp(a, env) ++
- i"ireturn" ++
- m".end method\n"
- }
- case Main(a) => {
- m".method public static main([Ljava/lang/String;)V" ++
- m".limit locals 200" ++
- m".limit stack 200" ++
- compile_exp(a, Map()) ++
- i"invokestatic XXX/XXX/write(I)V" ++
- i"return" ++
- m".end method\n"
- }
-}
-
-// the main compilation function
-def compile(prog: List[Decl], class_name: String) : String = {
- val instructions = prog.map(compile_decl).mkString
- (library + instructions).replaceAllLiterally("XXX", class_name)
-}
-
-
-
-
-// An example program (factorials)
-//
-// def fact(n) = if n == 0 then 1 else n * fact(n - 1);
-// def facT(n, acc) = if n == 0 then acc else facT(n - 1, n * acc);
-//
-// fact(10) ; facT(15, 1)
-//
-
-
-val test_prog =
- List(Def("fact", List("n"),
- If(Bop("==",Var("n"),Num(0)),
- Num(1),
- Aop("*",Var("n"),
- Call("fact",List(Aop("-",Var("n"),Num(1))))))),
-
- Def("facT",List("n", "acc"),
- If(Bop("==",Var("n"),Num(0)),
- Var("acc"),
- Call("facT",List(Aop("-",Var("n"),Num(1)),
- Aop("*",Var("n"),Var("acc")))))),
-
- Main(Sequ(Write(Call("fact",List(Num(10)))),
- Write(Call("facT",List(Num(10), Num(1)))))))
-
-// prints out the JVM instructions
-println(compile(test_prog, "fact"))
--- a/progs/fun.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,213 +0,0 @@
-// A Small Compiler for a Simple Functional Language
-// (includes an external lexer and parser)
-//
-// call with
-//
-// scala fun.scala fact
-//
-// scala fun.scala defs
-//
-// this will generate a .j file and run the jasmin
-// assembler (installed at jvm/jasmin-2.4/jasmin.jar)
-// it runs the resulting JVM file twice for timing
-// purposes.
-
-
-
-
-object Compiler {
-
-import java.io._
-import scala.util._
-import scala.sys.process._
-
-// Abstract syntax trees for the Fun language
-abstract class Exp extends Serializable
-abstract class BExp extends Serializable
-abstract class Decl extends Serializable
-
-case class Def(name: String, args: List[String], body: Exp) extends Decl
-case class Main(e: Exp) extends Decl
-
-case class Call(name: String, args: List[Exp]) extends Exp
-case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
-case class Write(e: Exp) extends Exp
-case class Var(s: String) extends Exp
-case class Num(i: Int) extends Exp
-case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
-case class Sequence(e1: Exp, e2: Exp) extends Exp
-case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
-
-
-// compiler - built-in functions
-// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
-//
-
-val library = """
-.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
- invokevirtual java/io/PrintStream/println(I)V
- return
-.end method
-
-"""
-
-// calculating the maximal needed stack size
-def max_stack_exp(e: Exp): Int = e match {
- case Call(_, args) => args.map(max_stack_exp).sum
- case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
- case Write(e) => max_stack_exp(e) + 1
- case Var(_) => 1
- case Num(_) => 1
- case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
- case Sequence(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
-}
-
-def max_stack_bexp(e: BExp): Int = e match {
- case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
-}
-
-
-// for generating new labels
-var counter = -1
-
-def Fresh(x: String) = {
- counter += 1
- x ++ "_" ++ counter.toString()
-}
-
-// convenient string interpolations
-// for instructions, labels and methods
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-implicit def sring_inters(sc: StringContext) = new {
- def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
- def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
- def m(args: Any*): String = sc.s(args:_*) ++ "\n"
-}
-
-
-type Env = Map[String, Int]
-
-// compile expressions
-def compile_exp(a: Exp, env : Env) : String = a match {
- case Num(i) => i"ldc $i"
- case Var(s) => i"iload ${env(s)}"
- case Aop("+", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"iadd"
- case Aop("-", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"isub"
- case Aop("*", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"imul"
- case Aop("/", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"idiv"
- case Aop("%", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"irem"
- case If(b, a1, a2) => {
- val if_else = Fresh("If_else")
- val if_end = Fresh("If_end")
- compile_bexp(b, env, if_else) ++
- compile_exp(a1, env) ++
- i"goto $if_end" ++
- l"$if_else" ++
- compile_exp(a2, env) ++
- l"$if_end"
- }
- case Call(name, args) => {
- val is = "I" * args.length
- args.map(a => compile_exp(a, env)).mkString ++
- i"invokestatic XXX/XXX/$name($is)I"
- }
- case Sequence(a1, a2) => {
- compile_exp(a1, env) ++ i"pop" ++ compile_exp(a2, env)
- }
- case Write(a1) => {
- compile_exp(a1, env) ++
- i"dup" ++
- i"invokestatic XXX/XXX/write(I)V"
- }
-}
-
-// compile boolean expressions
-def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
- case Bop("==", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpne $jmp"
- case Bop("!=", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpeq $jmp"
- case Bop("<", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpge $jmp"
- case Bop("<=", a1, a2) =>
- compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpgt $jmp"
-}
-
-// compile function for declarations and main
-def compile_decl(d: Decl) : String = d match {
- case Def(name, args, a) => {
- val env = args.zipWithIndex.toMap
- val is = "I" * args.length
- m".method public static $name($is)I" ++
- m".limit locals ${args.length}" ++
- m".limit stack ${1 + max_stack_exp(a)}" ++
- l"${name}_Start" ++
- compile_exp(a, env) ++
- i"ireturn" ++
- m".end method\n"
- }
- case Main(a) => {
- m".method public static main([Ljava/lang/String;)V" ++
- m".limit locals 200" ++
- m".limit stack 200" ++
- compile_exp(a, Map()) ++
- i"invokestatic XXX/XXX/write(I)V" ++
- i"return" ++
- m".end method\n"
- }
-}
-
-// main compiler functions
-
-def time_needed[T](i: Int, code: => T) = {
- val start = System.nanoTime()
- for (j <- 1 to i) code
- val end = System.nanoTime()
- (end - start)/(i * 1.0e9)
-}
-
-def deserialise[T](fname: String) : Try[T] = {
- import scala.util.Using
- Using(new ObjectInputStream(new FileInputStream(fname))) {
- in => in.readObject.asInstanceOf[T]
- }
-}
-
-def compile(class_name: String) : String = {
- val ast = deserialise[List[Decl]](class_name ++ ".prs").getOrElse(Nil)
- val instructions = ast.map(compile_decl).mkString
- (library + instructions).replaceAllLiterally("XXX", class_name)
-}
-
-def compile_to_file(class_name: String) = {
- val output = compile(class_name)
- scala.tools.nsc.io.File(s"${class_name}.j").writeAll(output)
-}
-
-def compile_and_run(class_name: String) : Unit = {
- compile_to_file(class_name)
- (s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
- println("Time: " + time_needed(1, (s"java ${class_name}/${class_name}").!))
-}
-
-
-// some examples of .fun files
-//compile_to_file("fact")
-//compile_and_run("fact")
-//compile_and_run("defs")
-
-
-def main(args: Array[String]) : Unit =
- compile_and_run(args(0))
-
-
-}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/fun-bare.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,187 @@
+// A Small Compiler for a Simple Functional Language
+// (it does not include a parser and lexer)
+
+// abstract syntax trees
+abstract class Exp
+abstract class BExp
+abstract class Decl
+
+// functions and declarations
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+// expressions
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequ(e1: Exp, e2: Exp) extends Exp
+
+// boolean expressions
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+// calculating the maximal needed stack size
+def max_stack_exp(e: Exp): Int = e match {
+ case Call(_, args) => args.map(max_stack_exp).sum
+ case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
+ case Write(e) => max_stack_exp(e) + 1
+ case Var(_) => 1
+ case Num(_) => 1
+ case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+ case Sequ(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
+}
+def max_stack_bexp(e: BExp): Int = e match {
+ case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+}
+
+// compiler - built-in functions
+// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
+//
+
+val library = """
+.class public XXX.XXX
+.super java/lang/Object
+
+.method public static write(I)V
+ .limit locals 5
+ .limit stack 5
+ iload 0
+ getstatic java/lang/System/out Ljava/io/PrintStream;
+ swap
+ invokevirtual java/io/PrintStream/println(I)V
+ return
+.end method
+
+"""
+
+// for generating new labels
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+// convenient string interpolations for
+// generating instructions, labels etc
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+// convenience for code-generation (string interpolations)
+implicit def sring_inters(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n" // instructions
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n" // labels
+ def m(args: Any*): String = sc.s(args:_*) ++ "\n" // methods
+}
+
+// variable / index environments
+type Env = Map[String, Int]
+
+// compile expressions
+def compile_exp(a: Exp, env : Env) : String = a match {
+ case Num(i) => i"ldc $i"
+ case Var(s) => i"iload ${env(s)}"
+ case Aop("+", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"iadd"
+ case Aop("-", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"isub"
+ case Aop("*", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"imul"
+ case Aop("/", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"idiv"
+ case Aop("%", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"irem"
+ case If(b, a1, a2) => {
+ val if_else = Fresh("If_else")
+ val if_end = Fresh("If_end")
+ compile_bexp(b, env, if_else) ++
+ compile_exp(a1, env) ++
+ i"goto $if_end" ++
+ l"$if_else" ++
+ compile_exp(a2, env) ++
+ l"$if_end"
+ }
+ case Call(name, args) => {
+ val is = "I" * args.length
+ args.map(a => compile_exp(a, env)).mkString ++
+ i"invokestatic XXX/XXX/$name($is)I"
+ }
+ case Sequ(a1, a2) => {
+ compile_exp(a1, env) ++ i"pop" ++ compile_exp(a2, env)
+ }
+ case Write(a1) => {
+ compile_exp(a1, env) ++
+ i"dup" ++
+ i"invokestatic XXX/XXX/write(I)V"
+ }
+}
+
+// compile boolean expressions
+def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
+ case Bop("==", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpne $jmp"
+ case Bop("!=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpeq $jmp"
+ case Bop("<", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpge $jmp"
+ case Bop("<=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpgt $jmp"
+}
+
+// compile functions and declarations
+def compile_decl(d: Decl) : String = d match {
+ case Def(name, args, a) => {
+ val env = args.zipWithIndex.toMap
+ val is = "I" * args.length
+ m".method public static $name($is)I" ++
+ m".limit locals ${args.length.toString}" ++
+ m".limit stack ${1 + max_stack_exp(a)}" ++
+ l"${name}_Start" ++
+ compile_exp(a, env) ++
+ i"ireturn" ++
+ m".end method\n"
+ }
+ case Main(a) => {
+ m".method public static main([Ljava/lang/String;)V" ++
+ m".limit locals 200" ++
+ m".limit stack 200" ++
+ compile_exp(a, Map()) ++
+ i"invokestatic XXX/XXX/write(I)V" ++
+ i"return" ++
+ m".end method\n"
+ }
+}
+
+// the main compilation function
+def compile(prog: List[Decl], class_name: String) : String = {
+ val instructions = prog.map(compile_decl).mkString
+ (library + instructions).replaceAllLiterally("XXX", class_name)
+}
+
+
+
+
+// An example program (factorials)
+//
+// def fact(n) = if n == 0 then 1 else n * fact(n - 1);
+// def facT(n, acc) = if n == 0 then acc else facT(n - 1, n * acc);
+//
+// fact(10) ; facT(15, 1)
+//
+
+
+val test_prog =
+ List(Def("fact", List("n"),
+ If(Bop("==",Var("n"),Num(0)),
+ Num(1),
+ Aop("*",Var("n"),
+ Call("fact",List(Aop("-",Var("n"),Num(1))))))),
+
+ Def("facT",List("n", "acc"),
+ If(Bop("==",Var("n"),Num(0)),
+ Var("acc"),
+ Call("facT",List(Aop("-",Var("n"),Num(1)),
+ Aop("*",Var("n"),Var("acc")))))),
+
+ Main(Sequ(Write(Call("fact",List(Num(10)))),
+ Write(Call("facT",List(Num(10), Num(1)))))))
+
+// prints out the JVM instructions
+println(compile(test_prog, "fact"))
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/fun.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,213 @@
+// A Small Compiler for a Simple Functional Language
+// (includes an external lexer and parser)
+//
+// call with
+//
+// scala fun.scala fact
+//
+// scala fun.scala defs
+//
+// this will generate a .j file and run the jasmin
+// assembler (installed at jvm/jasmin-2.4/jasmin.jar)
+// it runs the resulting JVM file twice for timing
+// purposes.
+
+
+
+
+object Compiler {
+
+import java.io._
+import scala.util._
+import scala.sys.process._
+
+// Abstract syntax trees for the Fun language
+abstract class Exp extends Serializable
+abstract class BExp extends Serializable
+abstract class Decl extends Serializable
+
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequence(e1: Exp, e2: Exp) extends Exp
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+
+// compiler - built-in functions
+// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
+//
+
+val library = """
+.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
+ invokevirtual java/io/PrintStream/println(I)V
+ return
+.end method
+
+"""
+
+// calculating the maximal needed stack size
+def max_stack_exp(e: Exp): Int = e match {
+ case Call(_, args) => args.map(max_stack_exp).sum
+ case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
+ case Write(e) => max_stack_exp(e) + 1
+ case Var(_) => 1
+ case Num(_) => 1
+ case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+ case Sequence(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
+}
+
+def max_stack_bexp(e: BExp): Int = e match {
+ case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+}
+
+
+// for generating new labels
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+// convenient string interpolations
+// for instructions, labels and methods
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+implicit def sring_inters(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
+ def m(args: Any*): String = sc.s(args:_*) ++ "\n"
+}
+
+
+type Env = Map[String, Int]
+
+// compile expressions
+def compile_exp(a: Exp, env : Env) : String = a match {
+ case Num(i) => i"ldc $i"
+ case Var(s) => i"iload ${env(s)}"
+ case Aop("+", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"iadd"
+ case Aop("-", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"isub"
+ case Aop("*", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"imul"
+ case Aop("/", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"idiv"
+ case Aop("%", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"irem"
+ case If(b, a1, a2) => {
+ val if_else = Fresh("If_else")
+ val if_end = Fresh("If_end")
+ compile_bexp(b, env, if_else) ++
+ compile_exp(a1, env) ++
+ i"goto $if_end" ++
+ l"$if_else" ++
+ compile_exp(a2, env) ++
+ l"$if_end"
+ }
+ case Call(name, args) => {
+ val is = "I" * args.length
+ args.map(a => compile_exp(a, env)).mkString ++
+ i"invokestatic XXX/XXX/$name($is)I"
+ }
+ case Sequence(a1, a2) => {
+ compile_exp(a1, env) ++ i"pop" ++ compile_exp(a2, env)
+ }
+ case Write(a1) => {
+ compile_exp(a1, env) ++
+ i"dup" ++
+ i"invokestatic XXX/XXX/write(I)V"
+ }
+}
+
+// compile boolean expressions
+def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
+ case Bop("==", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpne $jmp"
+ case Bop("!=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpeq $jmp"
+ case Bop("<", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpge $jmp"
+ case Bop("<=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpgt $jmp"
+}
+
+// compile function for declarations and main
+def compile_decl(d: Decl) : String = d match {
+ case Def(name, args, a) => {
+ val env = args.zipWithIndex.toMap
+ val is = "I" * args.length
+ m".method public static $name($is)I" ++
+ m".limit locals ${args.length}" ++
+ m".limit stack ${1 + max_stack_exp(a)}" ++
+ l"${name}_Start" ++
+ compile_exp(a, env) ++
+ i"ireturn" ++
+ m".end method\n"
+ }
+ case Main(a) => {
+ m".method public static main([Ljava/lang/String;)V" ++
+ m".limit locals 200" ++
+ m".limit stack 200" ++
+ compile_exp(a, Map()) ++
+ i"invokestatic XXX/XXX/write(I)V" ++
+ i"return" ++
+ m".end method\n"
+ }
+}
+
+// main compiler functions
+
+def time_needed[T](i: Int, code: => T) = {
+ val start = System.nanoTime()
+ for (j <- 1 to i) code
+ val end = System.nanoTime()
+ (end - start)/(i * 1.0e9)
+}
+
+def deserialise[T](fname: String) : Try[T] = {
+ import scala.util.Using
+ Using(new ObjectInputStream(new FileInputStream(fname))) {
+ in => in.readObject.asInstanceOf[T]
+ }
+}
+
+def compile(class_name: String) : String = {
+ val ast = deserialise[List[Decl]](class_name ++ ".prs").getOrElse(Nil)
+ val instructions = ast.map(compile_decl).mkString
+ (library + instructions).replaceAllLiterally("XXX", class_name)
+}
+
+def compile_to_file(class_name: String) = {
+ val output = compile(class_name)
+ scala.tools.nsc.io.File(s"${class_name}.j").writeAll(output)
+}
+
+def compile_and_run(class_name: String) : Unit = {
+ compile_to_file(class_name)
+ (s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
+ println("Time: " + time_needed(1, (s"java ${class_name}/${class_name}").!))
+}
+
+
+// some examples of .fun files
+//compile_to_file("fact")
+//compile_and_run("fact")
+//compile_and_run("defs")
+
+
+def main(args: Array[String]) : Unit =
+ compile_and_run(args(0))
+
+
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/fun_llvm.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,290 @@
+// A Small LLVM Compiler for a Simple Functional Language
+// (includes an external lexer and parser)
+//
+// call with
+//
+// scala fun_llvm.scala fact
+//
+// scala fun_llvm.scala defs
+//
+// this will generate a .ll file. You can interpret this file
+// using lli.
+//
+// The optimiser can be invoked as
+//
+// opt -O1 -S in_file.ll > out_file.ll
+// opt -O3 -S in_file.ll > out_file.ll
+//
+// The code produced for the various architectures can be obtains with
+//
+// llc -march=x86 -filetype=asm in_file.ll -o -
+// llc -march=arm -filetype=asm in_file.ll -o -
+//
+// Producing an executable can be achieved by
+//
+// llc -filetype=obj in_file.ll
+// gcc in_file.o -o a.out
+// ./a.out
+
+
+
+object Compiler {
+
+import java.io._
+import scala.util._
+import scala.sys.process._
+
+// Abstract syntax trees for the Fun language
+abstract class Exp extends Serializable
+abstract class BExp extends Serializable
+abstract class Decl extends Serializable
+
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequence(e1: Exp, e2: Exp) extends Exp
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+
+// for generating new labels
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+// Internal CPS language for FUN
+abstract class KExp
+abstract class KVal
+
+case class KVar(s: String) extends KVal
+case class KNum(i: Int) extends KVal
+case class Kop(o: String, v1: KVal, v2: KVal) extends KVal
+case class KCall(o: String, vrs: List[KVal]) extends KVal
+case class KWrite(v: KVal) extends KVal
+
+case class KIf(x1: String, e1: KExp, e2: KExp) extends KExp {
+ override def toString = s"KIf $x1\nIF\n$e1\nELSE\n$e2"
+}
+case class KLet(x: String, e1: KVal, e2: KExp) extends KExp {
+ override def toString = s"let $x = $e1 in \n$e2"
+}
+case class KReturn(v: KVal) extends KExp
+
+
+// CPS translation from Exps to KExps using a
+// continuation k.
+def CPS(e: Exp)(k: KVal => KExp) : KExp = e match {
+ case Var(s) => k(KVar(s))
+ case Num(i) => k(KNum(i))
+ case Aop(o, e1, e2) => {
+ val z = Fresh("tmp")
+ CPS(e1)(y1 =>
+ CPS(e2)(y2 => KLet(z, Kop(o, y1, y2), k(KVar(z)))))
+ }
+ case If(Bop(o, b1, b2), e1, e2) => {
+ val z = Fresh("tmp")
+ CPS(b1)(y1 =>
+ CPS(b2)(y2 =>
+ KLet(z, Kop(o, y1, y2), KIf(z, CPS(e1)(k), CPS(e2)(k)))))
+ }
+ case Call(name, args) => {
+ def aux(args: List[Exp], vs: List[KVal]) : KExp = args match {
+ case Nil => {
+ val z = Fresh("tmp")
+ KLet(z, KCall(name, vs), k(KVar(z)))
+ }
+ case e::es => CPS(e)(y => aux(es, vs ::: List(y)))
+ }
+ aux(args, Nil)
+ }
+ case Sequence(e1, e2) =>
+ CPS(e1)(_ => CPS(e2)(y2 => k(y2)))
+ case Write(e) => {
+ val z = Fresh("tmp")
+ CPS(e)(y => KLet(z, KWrite(y), k(KVar(z))))
+ }
+}
+
+//initial continuation
+def CPSi(e: Exp) = CPS(e)(KReturn)
+
+// some testcases
+val e1 = Aop("*", Var("a"), Num(3))
+CPSi(e1)
+
+val e2 = Aop("+", Aop("*", Var("a"), Num(3)), Num(4))
+CPSi(e2)
+
+val e3 = Aop("+", Num(2), Aop("*", Var("a"), Num(3)))
+CPSi(e3)
+
+val e4 = Aop("+", Aop("-", Num(1), Num(2)), Aop("*", Var("a"), Num(3)))
+CPSi(e4)
+
+val e5 = If(Bop("==", Num(1), Num(1)), Num(3), Num(4))
+CPSi(e5)
+
+val e6 = If(Bop("!=", Num(10), Num(10)), e5, Num(40))
+CPSi(e6)
+
+val e7 = Call("foo", List(Num(3)))
+CPSi(e7)
+
+val e8 = Call("foo", List(Aop("*", Num(3), Num(1)), Num(4), Aop("+", Num(5), Num(6))))
+CPSi(e8)
+
+val e9 = Sequence(Aop("*", Var("a"), Num(3)), Aop("+", Var("b"), Num(6)))
+CPSi(e9)
+
+val e = Aop("*", Aop("+", Num(1), Call("foo", List(Var("a"), Num(3)))), Num(4))
+CPSi(e)
+
+
+
+
+// convenient string interpolations
+// for instructions, labels and methods
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+implicit def sring_inters(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
+ def m(args: Any*): String = sc.s(args:_*) ++ "\n"
+}
+
+// mathematical and boolean operations
+def compile_op(op: String) = op match {
+ case "+" => "add i32 "
+ case "*" => "mul i32 "
+ case "-" => "sub i32 "
+ case "/" => "sdiv i32 "
+ case "%" => "srem i32 "
+ case "==" => "icmp eq i32 "
+ case "<=" => "icmp sle i32 " // signed less or equal
+ case "<" => "icmp slt i32 " // signed less than
+}
+
+def compile_val(v: KVal) : String = v match {
+ case KNum(i) => s"$i"
+ case KVar(s) => s"%$s"
+ case Kop(op, x1, x2) =>
+ s"${compile_op(op)} ${compile_val(x1)}, ${compile_val(x2)}"
+ case KCall(x1, args) =>
+ s"call i32 @$x1 (${args.map(compile_val).mkString("i32 ", ", i32 ", "")})"
+ case KWrite(x1) =>
+ s"call i32 @printInt (i32 ${compile_val(x1)})"
+}
+
+// compile K expressions
+def compile_exp(a: KExp) : String = a match {
+ case KReturn(v) =>
+ i"ret i32 ${compile_val(v)}"
+ case KLet(x: String, v: KVal, e: KExp) =>
+ i"%$x = ${compile_val(v)}" ++ compile_exp(e)
+ case KIf(x, e1, e2) => {
+ val if_br = Fresh("if_branch")
+ val else_br = Fresh("else_branch")
+ i"br i1 %$x, label %$if_br, label %$else_br" ++
+ l"\n$if_br" ++
+ compile_exp(e1) ++
+ l"\n$else_br" ++
+ compile_exp(e2)
+ }
+}
+
+
+val prelude = """
+@.str = private constant [4 x i8] c"%d\0A\00"
+
+declare i32 @printf(i8*, ...)
+
+define i32 @printInt(i32 %x) {
+ %t0 = getelementptr [4 x i8], [4 x i8]* @.str, i32 0, i32 0
+ call i32 (i8*, ...) @printf(i8* %t0, i32 %x)
+ ret i32 %x
+}
+
+"""
+
+
+// compile function for declarations and main
+def compile_decl(d: Decl) : String = d match {
+ case Def(name, args, body) => {
+ m"define i32 @$name (${args.mkString("i32 %", ", i32 %", "")}) {" ++
+ compile_exp(CPSi(body)) ++
+ m"}\n"
+ }
+ case Main(body) => {
+ m"define i32 @main() {" ++
+ compile_exp(CPSi(body)) ++
+ m"}\n"
+ }
+}
+
+// main compiler functions
+
+def time_needed[T](i: Int, code: => T) = {
+ val start = System.nanoTime()
+ for (j <- 1 to i) code
+ val end = System.nanoTime()
+ (end - start)/(i * 1.0e9)
+}
+
+// for Scala 2.12
+/*
+def deserialise[T](file: String) : Try[T] = {
+ val in = new ObjectInputStream(new FileInputStream(new File(file)))
+ val obj = Try(in.readObject().asInstanceOf[T])
+ in.close()
+ obj
+}
+*/
+
+def deserialise[T](fname: String) : Try[T] = {
+ import scala.util.Using
+ Using(new ObjectInputStream(new FileInputStream(fname))) {
+ in => in.readObject.asInstanceOf[T]
+ }
+}
+
+def compile(fname: String) : String = {
+ val ast = deserialise[List[Decl]](fname ++ ".prs").getOrElse(Nil)
+ prelude ++ (ast.map(compile_decl).mkString)
+}
+
+def compile_to_file(fname: String) = {
+ val output = compile(fname)
+ scala.tools.nsc.io.File(s"${fname}.ll").writeAll(output)
+}
+
+def compile_and_run(fname: String) : Unit = {
+ compile_to_file(fname)
+ (s"llc -filetype=obj ${fname}.ll").!!
+ (s"gcc ${fname}.o -o a.out").!!
+ println("Time: " + time_needed(2, (s"./a.out").!))
+}
+
+// some examples of .fun files
+//compile_to_file("fact")
+//compile_and_run("fact")
+//compile_and_run("defs")
+
+
+def main(args: Array[String]) : Unit =
+ //println(compile(args(0)))
+ compile_and_run(args(0))
+}
+
+
+
+
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/fun_parser.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,199 @@
+// A parser for the Fun language
+//================================
+//
+// call with
+//
+// scala fun_parser.scala fact.tks
+//
+// scala fun_parser.scala defs.tks
+//
+// this will generate a .prs file that can be deserialised back
+// into a list of declarations
+
+object Fun_Parser {
+
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+import scala.util._
+import java.io._
+
+abstract class Token extends Serializable
+case object T_SEMI extends Token
+case object T_COMMA extends Token
+case object T_LPAREN extends Token
+case object T_RPAREN extends Token
+case class T_ID(s: String) extends Token
+case class T_OP(s: String) extends Token
+case class T_NUM(n: Int) extends Token
+case class T_KWD(s: String) extends Token
+
+
+// Parser combinators
+// type parameter I needs to be of Seq-type
+//
+abstract class Parser[I, T](implicit ev: I => Seq[_]) {
+ def parse(ts: I): Set[(T, I)]
+
+ def parse_single(ts: I) : T =
+ parse(ts).partition(_._2.isEmpty) match {
+ case (good, _) if !good.isEmpty => good.head._1
+ case (_, err) => {
+ println (s"Parse Error\n${err.minBy(_._2.length)}") ; sys.exit(-1) }
+ }
+}
+
+// convenience for writing grammar rules
+case class ~[+A, +B](_1: A, _2: B)
+
+class SeqParser[I, T, S](p: => Parser[I, T],
+ q: => Parser[I, S])(implicit ev: I => Seq[_]) extends Parser[I, ~[T, S]] {
+ def parse(sb: I) =
+ for ((head1, tail1) <- p.parse(sb);
+ (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
+}
+
+class AltParser[I, T](p: => Parser[I, T],
+ q: => Parser[I, T])(implicit ev: I => Seq[_]) extends Parser[I, T] {
+ def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
+}
+
+class FunParser[I, T, S](p: => Parser[I, T],
+ f: T => S)(implicit ev: I => Seq[_]) extends Parser[I, S] {
+ def parse(sb: I) =
+ for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
+}
+
+// convenient combinators
+implicit def ParserOps[I, T](p: Parser[I, T])(implicit ev: I => Seq[_]) = new {
+ def || (q : => Parser[I, T]) = new AltParser[I, T](p, q)
+ def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
+ def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
+}
+
+def ListParser[I, T, S](p: => Parser[I, T],
+ q: => Parser[I, S])(implicit ev: I => Seq[_]): Parser[I, List[T]] = {
+ (p ~ q ~ ListParser(p, q)) ==> { case x ~ _ ~ z => x :: z : List[T] } ||
+ (p ==> ((s) => List(s)))
+}
+
+case class TokParser(tok: Token) extends Parser[List[Token], Token] {
+ def parse(ts: List[Token]) = ts match {
+ case t::ts if (t == tok) => Set((t, ts))
+ case _ => Set ()
+ }
+}
+
+implicit def token2tparser(t: Token) = TokParser(t)
+
+implicit def TokOps(t: Token) = new {
+ def || (q : => Parser[List[Token], Token]) = new AltParser[List[Token], Token](t, q)
+ def ==>[S] (f: => Token => S) = new FunParser[List[Token], Token, S](t, f)
+ def ~[S](q : => Parser[List[Token], S]) = new SeqParser[List[Token], Token, S](t, q)
+}
+
+case object NumParser extends Parser[List[Token], Int] {
+ def parse(ts: List[Token]) = ts match {
+ case T_NUM(n)::ts => Set((n, ts))
+ case _ => Set ()
+ }
+}
+
+case object IdParser extends Parser[List[Token], String] {
+ def parse(ts: List[Token]) = ts match {
+ case T_ID(s)::ts => Set((s, ts))
+ case _ => Set ()
+ }
+}
+
+
+
+// Abstract syntax trees for the Fun language
+abstract class Exp extends Serializable
+abstract class BExp extends Serializable
+abstract class Decl extends Serializable
+
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequence(e1: Exp, e2: Exp) extends Exp
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+
+
+// Grammar Rules for the Fun language
+
+// arithmetic expressions
+lazy val Exp: Parser[List[Token], Exp] =
+ (T_KWD("if") ~ BExp ~ T_KWD("then") ~ Exp ~ T_KWD("else") ~ Exp) ==>
+ { case _ ~ x ~ _ ~ y ~ _ ~ z => If(x, y, z): Exp } ||
+ (M ~ T_SEMI ~ Exp) ==> { case x ~ _ ~ y => Sequence(x, y): Exp } || M
+lazy val M: Parser[List[Token], Exp] =
+ (T_KWD("write") ~ L) ==> { case _ ~ y => Write(y): Exp } || L
+lazy val L: Parser[List[Token], Exp] =
+ (T ~ T_OP("+") ~ Exp) ==> { case x ~ _ ~ z => Aop("+", x, z): Exp } ||
+ (T ~ T_OP("-") ~ Exp) ==> { case x ~ _ ~ z => Aop("-", x, z): Exp } || T
+lazy val T: Parser[List[Token], Exp] =
+ (F ~ T_OP("*") ~ T) ==> { case x ~ _ ~ z => Aop("*", x, z): Exp } ||
+ (F ~ T_OP("/") ~ T) ==> { case x ~ _ ~ z => Aop("/", x, z): Exp } ||
+ (F ~ T_OP("%") ~ T) ==> { case x ~ _ ~ z => Aop("%", x, z): Exp } || F
+lazy val F: Parser[List[Token], Exp] =
+ (IdParser ~ T_LPAREN ~ ListParser(Exp, T_COMMA) ~ T_RPAREN) ==>
+ { case x ~ _ ~ z ~ _ => Call(x, z): Exp } ||
+ (T_LPAREN ~ Exp ~ T_RPAREN) ==> { case _ ~ y ~ _ => y: Exp } ||
+ IdParser ==> { case x => Var(x): Exp } ||
+ NumParser ==> { case x => Num(x): Exp }
+
+// boolean expressions
+lazy val BExp: Parser[List[Token], BExp] =
+ (Exp ~ T_OP("==") ~ Exp) ==> { case x ~ _ ~ z => Bop("==", x, z): BExp } ||
+ (Exp ~ T_OP("!=") ~ Exp) ==> { case x ~ _ ~ z => Bop("!=", x, z): BExp } ||
+ (Exp ~ T_OP("<") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", x, z): BExp } ||
+ (Exp ~ T_OP(">") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", z, x): BExp } ||
+ (Exp ~ T_OP("<=") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", x, z): BExp } ||
+ (Exp ~ T_OP("=>") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", z, x): BExp }
+
+lazy val Defn: Parser[List[Token], Decl] =
+ (T_KWD("def") ~ IdParser ~ T_LPAREN ~ ListParser(IdParser, T_COMMA) ~ T_RPAREN ~ T_OP("=") ~ Exp) ==>
+ { case _ ~ y ~ _ ~ w ~ _ ~ _ ~ r => Def(y, w, r): Decl }
+
+lazy val Prog: Parser[List[Token], List[Decl]] =
+ (Defn ~ T_SEMI ~ Prog) ==> { case x ~ _ ~ z => x :: z : List[Decl] } ||
+ (Exp ==> ((s) => List(Main(s)) : List[Decl]))
+
+
+
+// Reading tokens and Writing parse trees
+
+def serialise[T](fname: String, data: T) = {
+ import scala.util.Using
+ Using(new ObjectOutputStream(new FileOutputStream(fname))) {
+ out => out.writeObject(data)
+ }
+}
+
+def deserialise[T](fname: String) : Try[T] = {
+ import scala.util.Using
+ Using(new ObjectInputStream(new FileInputStream(fname))) {
+ in => in.readObject.asInstanceOf[T]
+ }
+}
+
+
+def main(args: Array[String]) : Unit= {
+ val fname = args(0)
+ val pname = fname.stripSuffix(".tks") ++ ".prs"
+ val tks = deserialise[List[Token]](fname).getOrElse(Nil)
+ serialise(pname, Prog.parse_single(tks))
+
+ // testing whether read-back is working
+ //val ptree = deserialise[List[Decl]](pname).get
+ //println(s"Reading back from ${pname}:\n${ptree.mkString("\n")}")
+}
+
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/fun_tokens.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,273 @@
+// A tokeniser for the Fun language
+//==================================
+//
+// call with
+//
+// scala fun_tokens.scala fact.fun
+//
+// scala fun_tokens.scala defs.fun
+//
+// this will generate a .tks file that can be deserialised back
+// into a list of tokens
+// you can add -Xno-patmat-analysis in order to get rid of the
+// match-not-exhaustive warning
+
+object Fun_Tokens {
+
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+abstract class Rexp
+case object ZERO extends Rexp
+case object ONE 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 Empty 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
+
+// some convenience for typing in regular expressions
+def charlist2rexp(s : List[Char]): Rexp = s match {
+ case Nil => ONE
+ case c::Nil => CHAR(c)
+ case c::s => SEQ(CHAR(c), charlist2rexp(s))
+}
+implicit def string2rexp(s : String) : Rexp =
+ charlist2rexp(s.toList)
+
+implicit def RexpOps(r: Rexp) = new {
+ def | (s: Rexp) = ALT(r, s)
+ def % = STAR(r)
+ def ~ (s: Rexp) = SEQ(r, s)
+}
+
+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)
+}
+
+def nullable (r: Rexp) : Boolean = r match {
+ case ZERO => false
+ case ONE => 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)
+}
+
+def der (c: Char, r: Rexp) : Rexp = r match {
+ case ZERO => ZERO
+ case ONE => ZERO
+ case CHAR(d) => if (c == d) ONE else ZERO
+ 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)
+}
+
+
+// extracts a string from value
+def flatten(v: Val) : String = v match {
+ case Empty => ""
+ 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)
+}
+
+// extracts an environment from a value;
+// used for tokenise a string
+def env(v: Val) : List[(String, String)] = v match {
+ case Empty => 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)
+}
+
+// The Injection Part of the lexer
+
+def mkeps(r: Rexp) : Val = r match {
+ case ONE => Empty
+ 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))
+}
+
+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), Empty) => Chr(c)
+ case (RECD(x, r1), _) => Rec(x, inj(r1, c, v))
+ case _ => { println ("Injection error") ; sys.exit(-1) }
+}
+
+// some "rectification" functions for simplification
+def F_ID(v: Val): Val = v
+def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))
+def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))
+def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
+ case Right(v) => Right(f2(v))
+ case Left(v) => Left(f1(v))
+}
+def F_SEQ(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
+ case Sequ(v1, v2) => Sequ(f1(v1), f2(v2))
+}
+def F_SEQ_Empty1(f1: Val => Val, f2: Val => Val) =
+ (v:Val) => Sequ(f1(Empty), f2(v))
+def F_SEQ_Empty2(f1: Val => Val, f2: Val => Val) =
+ (v:Val) => Sequ(f1(v), f2(Empty))
+def F_RECD(f: Val => Val) = (v:Val) => v match {
+ case Rec(x, v) => Rec(x, f(v))
+}
+def F_ERROR(v: Val): Val = throw new Exception("error")
+
+def simp(r: Rexp): (Rexp, Val => Val) = r match {
+ case ALT(r1, r2) => {
+ val (r1s, f1s) = simp(r1)
+ val (r2s, f2s) = simp(r2)
+ (r1s, r2s) match {
+ case (ZERO, _) => (r2s, F_RIGHT(f2s))
+ case (_, ZERO) => (r1s, F_LEFT(f1s))
+ case _ => if (r1s == r2s) (r1s, F_LEFT(f1s))
+ else (ALT (r1s, r2s), F_ALT(f1s, f2s))
+ }
+ }
+ case SEQ(r1, r2) => {
+ val (r1s, f1s) = simp(r1)
+ val (r2s, f2s) = simp(r2)
+ (r1s, r2s) match {
+ case (ZERO, _) => (ZERO, F_ERROR)
+ case (_, ZERO) => (ZERO, F_ERROR)
+ case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))
+ case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))
+ case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))
+ }
+ }
+ case RECD(x, r1) => {
+ val (r1s, f1s) = simp(r1)
+ (RECD(x, r1s), F_RECD(f1s))
+ }
+ case r => (r, F_ID)
+}
+
+// lexing functions including simplification
+def lex_simp(r: Rexp, s: List[Char]) : Val = s match {
+ case Nil => if (nullable(r)) mkeps(r) else { println ("Lexing Error") ; sys.exit(-1) }
+ case c::cs => {
+ val (r_simp, f_simp) = simp(der(c, r))
+ inj(r, c, f_simp(lex_simp(r_simp, cs)))
+ }
+}
+
+def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))
+
+
+// The Lexing Rules for the Fun Language
+
+def PLUS(r: Rexp) = r ~ r.%
+
+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" | "T" | "_"
+val DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
+val ID = SYM ~ (SYM | DIGIT).%
+val NUM = PLUS(DIGIT)
+val KEYWORD : Rexp = "if" | "then" | "else" | "write" | "def"
+val SEMI: Rexp = ";"
+val OP: Rexp = "=" | "==" | "-" | "+" | "*" | "!=" | "<" | ">" | "<=" | ">=" | "%" | "/"
+val WHITESPACE = PLUS(" " | "\n" | "\t")
+val RPAREN: Rexp = ")"
+val LPAREN: Rexp = "("
+val COMMA: Rexp = ","
+val ALL = SYM | DIGIT | OP | " " | ":" | ";" | "\"" | "=" | "," | "(" | ")"
+val ALL2 = ALL | "\n"
+val COMMENT = ("/*" ~ ALL2.% ~ "*/") | ("//" ~ ALL.% ~ "\n")
+
+
+val FUN_REGS = (("k" $ KEYWORD) |
+ ("i" $ ID) |
+ ("o" $ OP) |
+ ("n" $ NUM) |
+ ("s" $ SEMI) |
+ ("c" $ COMMA) |
+ ("pl" $ LPAREN) |
+ ("pr" $ RPAREN) |
+ ("w" $ (WHITESPACE | COMMENT))).%
+
+
+
+// The tokens for the Fun language
+
+import java.io._
+
+abstract class Token extends Serializable
+case object T_SEMI extends Token
+case object T_COMMA extends Token
+case object T_LPAREN extends Token
+case object T_RPAREN extends Token
+case class T_ID(s: String) extends Token
+case class T_OP(s: String) extends Token
+case class T_NUM(n: Int) extends Token
+case class T_KWD(s: String) extends Token
+
+val token : PartialFunction[(String, String), Token] = {
+ case ("k", s) => T_KWD(s)
+ case ("i", s) => T_ID(s)
+ case ("o", s) => T_OP(s)
+ case ("n", s) => T_NUM(s.toInt)
+ case ("s", _) => T_SEMI
+ case ("c", _) => T_COMMA
+ case ("pl", _) => T_LPAREN
+ case ("pr", _) => T_RPAREN
+}
+
+
+def tokenise(s: String) : List[Token] = {
+ val tks = lexing_simp(FUN_REGS, s).collect(token)
+ if (tks.length != 0) tks
+ else { println (s"Tokenise Error") ; sys.exit(-1) }
+}
+
+def serialise[T](fname: String, data: T) = {
+ import scala.util.Using
+ Using(new ObjectOutputStream(new FileOutputStream(fname))) {
+ out => out.writeObject(data)
+ }
+}
+
+def main(args: Array[String]) : Unit = {
+ val fname = args(0)
+ val tname = fname.stripSuffix(".fun") ++ ".tks"
+ val file = io.Source.fromFile(fname).mkString
+ serialise(tname, tokenise(file))
+}
+
+
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun/funt.scala Sat Jul 04 22:12:18 2020 +0100
@@ -0,0 +1,543 @@
+// A Small Compiler for a Simple Functional Language
+// (includes a lexer and a parser)
+
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+abstract class Rexp
+case object ZERO extends Rexp
+case object ONE 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 Empty 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
+
+// some convenience for typing in regular expressions
+def charlist2rexp(s : List[Char]): Rexp = s match {
+ case Nil => ONE
+ case c::Nil => CHAR(c)
+ case c::s => SEQ(CHAR(c), charlist2rexp(s))
+}
+implicit def string2rexp(s : String) : Rexp =
+ charlist2rexp(s.toList)
+
+implicit def RexpOps(r: Rexp) = new {
+ def | (s: Rexp) = ALT(r, s)
+ def % = STAR(r)
+ def ~ (s: Rexp) = SEQ(r, s)
+}
+
+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)
+}
+
+def nullable (r: Rexp) : Boolean = r match {
+ case ZERO => false
+ case ONE => 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)
+}
+
+def der (c: Char, r: Rexp) : Rexp = r match {
+ case ZERO => ZERO
+ case ONE => ZERO
+ case CHAR(d) => if (c == d) ONE else ZERO
+ 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)
+}
+
+
+// extracts a string from value
+def flatten(v: Val) : String = v match {
+ case Empty => ""
+ 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)
+}
+
+// extracts an environment from a value;
+// used for tokenise a string
+def env(v: Val) : List[(String, String)] = v match {
+ case Empty => 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)
+}
+
+// The Injection Part of the lexer
+
+def mkeps(r: Rexp) : Val = r match {
+ case ONE => Empty
+ 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))
+}
+
+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), Empty) => Chr(c)
+ case (RECD(x, r1), _) => Rec(x, inj(r1, c, v))
+ case _ => { println ("Injection error") ; sys.exit(-1) }
+}
+
+// some "rectification" functions for simplification
+def F_ID(v: Val): Val = v
+def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))
+def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))
+def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
+ case Right(v) => Right(f2(v))
+ case Left(v) => Left(f1(v))
+}
+def F_SEQ(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
+ case Sequ(v1, v2) => Sequ(f1(v1), f2(v2))
+}
+def F_SEQ_Empty1(f1: Val => Val, f2: Val => Val) =
+ (v:Val) => Sequ(f1(Empty), f2(v))
+def F_SEQ_Empty2(f1: Val => Val, f2: Val => Val) =
+ (v:Val) => Sequ(f1(v), f2(Empty))
+def F_RECD(f: Val => Val) = (v:Val) => v match {
+ case Rec(x, v) => Rec(x, f(v))
+}
+def F_ERROR(v: Val): Val = throw new Exception("error")
+
+def simp(r: Rexp): (Rexp, Val => Val) = r match {
+ case ALT(r1, r2) => {
+ val (r1s, f1s) = simp(r1)
+ val (r2s, f2s) = simp(r2)
+ (r1s, r2s) match {
+ case (ZERO, _) => (r2s, F_RIGHT(f2s))
+ case (_, ZERO) => (r1s, F_LEFT(f1s))
+ case _ => if (r1s == r2s) (r1s, F_LEFT(f1s))
+ else (ALT (r1s, r2s), F_ALT(f1s, f2s))
+ }
+ }
+ case SEQ(r1, r2) => {
+ val (r1s, f1s) = simp(r1)
+ val (r2s, f2s) = simp(r2)
+ (r1s, r2s) match {
+ case (ZERO, _) => (ZERO, F_ERROR)
+ case (_, ZERO) => (ZERO, F_ERROR)
+ case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))
+ case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))
+ case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))
+ }
+ }
+ case RECD(x, r1) => {
+ val (r1s, f1s) = simp(r1)
+ (RECD(x, r1s), F_RECD(f1s))
+ }
+ case r => (r, F_ID)
+}
+
+// lexing functions including simplification
+def lex_simp(r: Rexp, s: List[Char]) : Val = s match {
+ case Nil => if (nullable(r)) mkeps(r) else { println ("Lexing Error") ; sys.exit(-1) }
+ case c::cs => {
+ val (r_simp, f_simp) = simp(der(c, r))
+ inj(r, c, f_simp(lex_simp(r_simp, cs)))
+ }
+}
+
+def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))
+
+
+// The Lexing Rules for the Fun Language
+
+def PLUS(r: Rexp) = r ~ r.%
+
+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" | "T" | "_"
+val DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
+val ID = SYM ~ (SYM | DIGIT).%
+val NUM = PLUS(DIGIT)
+val KEYWORD : Rexp = "if" | "then" | "else" | "write" | "def"
+val SEMI: Rexp = ";"
+val OP: Rexp = "=" | "==" | "-" | "+" | "*" | "!=" | "<" | ">" | "<=" | ">=" | "%" | "/"
+val WHITESPACE = PLUS(" " | "\n" | "\t")
+val RPAREN: Rexp = ")"
+val LPAREN: Rexp = "("
+val COMMA: Rexp = ","
+val ALL = SYM | DIGIT | OP | " " | ":" | ";" | "\"" | "=" | "," | "(" | ")"
+val ALL2 = ALL | "\n"
+val COMMENT = ("/*" ~ ALL2.% ~ "*/") | ("//" ~ ALL.% ~ "\n")
+
+
+val WHILE_REGS = (("k" $ KEYWORD) |
+ ("i" $ ID) |
+ ("o" $ OP) |
+ ("n" $ NUM) |
+ ("s" $ SEMI) |
+ ("c" $ COMMA) |
+ ("pl" $ LPAREN) |
+ ("pr" $ RPAREN) |
+ ("w" $ (WHITESPACE | COMMENT))).%
+
+
+
+// The tokens for the Fun language
+
+abstract class Token
+case object T_SEMI extends Token
+case object T_COMMA extends Token
+case object T_LPAREN extends Token
+case object T_RPAREN extends Token
+case class T_ID(s: String) extends Token
+case class T_OP(s: String) extends Token
+case class T_NUM(n: Int) extends Token
+case class T_KWD(s: String) extends Token
+
+val token : PartialFunction[(String, String), Token] = {
+ case ("k", s) => T_KWD(s)
+ case ("i", s) => T_ID(s)
+ case ("o", s) => T_OP(s)
+ case ("n", s) => T_NUM(s.toInt)
+ case ("s", _) => T_SEMI
+ case ("c", _) => T_COMMA
+ case ("pl", _) => T_LPAREN
+ case ("pr", _) => T_RPAREN
+}
+
+
+def tokenise(s: String) : List[Token] =
+ lexing_simp(WHILE_REGS, s).collect(token)
+
+
+
+// Parser combinators
+abstract class Parser[I, T](implicit ev: I => Seq[_]) {
+ def parse(ts: I): Set[(T, I)]
+
+ def parse_all(ts: I) : Set[T] =
+ for ((head, tail) <- parse(ts); if (tail.isEmpty)) yield head
+
+ def parse_single(ts: I) : T = parse_all(ts).toList match {
+ case List(t) => t
+ case _ => { println ("Parse Error\n") ; sys.exit(-1) }
+ }
+}
+
+// convenience for matching later on
+case class ~[+A, +B](_1: A, _2: B)
+
+
+class SeqParser[I, T, S](p: => Parser[I, T],
+ q: => Parser[I, S])(implicit ev: I => Seq[_]) extends Parser[I, ~[T, S]] {
+ def parse(sb: I) =
+ for ((head1, tail1) <- p.parse(sb);
+ (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
+}
+
+class AltParser[I, T](p: => Parser[I, T],
+ q: => Parser[I, T])(implicit ev: I => Seq[_]) extends Parser[I, T] {
+ def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
+}
+
+class FunParser[I, T, S](p: => Parser[I, T],
+ f: T => S)(implicit ev: I => Seq[_]) extends Parser[I, S] {
+ def parse(sb: I) =
+ for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
+}
+
+implicit def ParserOps[I, T](p: Parser[I, T])(implicit ev: I => Seq[_]) = new {
+ def || (q : => Parser[I, T]) = new AltParser[I, T](p, q)
+ def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
+ def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
+}
+
+def ListParser[I, T, S](p: => Parser[I, T],
+ q: => Parser[I, S])(implicit ev: I => Seq[_]): Parser[I, List[T]] = {
+ (p ~ q ~ ListParser(p, q)) ==> { case x ~ _ ~ z => x :: z : List[T] } ||
+ (p ==> ((s) => List(s)))
+}
+
+case class TokParser(tok: Token) extends Parser[List[Token], Token] {
+ def parse(ts: List[Token]) = ts match {
+ case t::ts if (t == tok) => Set((t, ts))
+ case _ => Set ()
+ }
+}
+
+implicit def token2tparser(t: Token) = TokParser(t)
+
+implicit def TokOps(t: Token) = new {
+ def || (q : => Parser[List[Token], Token]) = new AltParser[List[Token], Token](t, q)
+ def ==>[S] (f: => Token => S) = new FunParser[List[Token], Token, S](t, f)
+ def ~[S](q : => Parser[List[Token], S]) = new SeqParser[List[Token], Token, S](t, q)
+}
+
+case object NumParser extends Parser[List[Token], Int] {
+ def parse(ts: List[Token]) = ts match {
+ case T_NUM(n)::ts => Set((n, ts))
+ case _ => Set ()
+ }
+}
+
+case object IdParser extends Parser[List[Token], String] {
+ def parse(ts: List[Token]) = ts match {
+ case T_ID(s)::ts => Set((s, ts))
+ case _ => Set ()
+ }
+}
+
+
+
+// Abstract syntax trees for Fun
+abstract class Exp
+abstract class BExp
+abstract class Decl
+
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequence(e1: Exp, e2: Exp) extends Exp
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+
+
+// Grammar Rules for Fun
+
+// arithmetic expressions
+lazy val Exp: Parser[List[Token], Exp] =
+ (T_KWD("if") ~ BExp ~ T_KWD("then") ~ Exp ~ T_KWD("else") ~ Exp) ==>
+ { case _ ~ y ~ _ ~ u ~ _ ~ w => If(y, u, w): Exp } ||
+ (M ~ T_SEMI ~ Exp) ==> { case x ~ _ ~ z => Sequence(x, z): Exp } || M
+lazy val M: Parser[List[Token], Exp] =
+ (T_KWD("write") ~ L) ==> { case _ ~ y => Write(y): Exp } || L
+lazy val L: Parser[List[Token], Exp] =
+ (T ~ T_OP("+") ~ Exp) ==> { case x ~ _ ~ z => Aop("+", x, z): Exp } ||
+ (T ~ T_OP("-") ~ Exp) ==> { case x ~ _ ~ z => Aop("-", x, z): Exp } || T
+lazy val T: Parser[List[Token], Exp] =
+ (F ~ T_OP("*") ~ T) ==> { case x ~ _ ~ z => Aop("*", x, z): Exp } ||
+ (F ~ T_OP("/") ~ T) ==> { case x ~ _ ~ z => Aop("/", x, z): Exp } ||
+ (F ~ T_OP("%") ~ T) ==> { case x ~ _ ~ z => Aop("%", x, z): Exp } || F
+lazy val F: Parser[List[Token], Exp] =
+ (IdParser ~ T_LPAREN ~ ListParser(Exp, T_COMMA) ~ T_RPAREN) ==>
+ { case x ~ _ ~ z ~ _ => Call(x, z): Exp } ||
+ (T_LPAREN ~ Exp ~ T_RPAREN) ==> { case _ ~ y ~ _ => y: Exp } ||
+ IdParser ==> { case x => Var(x): Exp } ||
+ NumParser ==> { case x => Num(x): Exp }
+
+// boolean expressions
+lazy val BExp: Parser[List[Token], BExp] =
+ (Exp ~ T_OP("==") ~ Exp) ==> { case x ~ _ ~ z => Bop("==", x, z): BExp } ||
+ (Exp ~ T_OP("!=") ~ Exp) ==> { case x ~ _ ~ z => Bop("!=", x, z): BExp } ||
+ (Exp ~ T_OP("<") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", x, z): BExp } ||
+ (Exp ~ T_OP(">") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", z, x): BExp } ||
+ (Exp ~ T_OP("<=") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", x, z): BExp } ||
+ (Exp ~ T_OP("=>") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", z, x): BExp }
+
+lazy val Defn: Parser[List[Token], Decl] =
+ (T_KWD("def") ~ IdParser ~ T_LPAREN ~ ListParser(IdParser, T_COMMA) ~ T_RPAREN ~ T_OP("=") ~ Exp) ==>
+ { case x ~ y ~ z ~ w ~ u ~ v ~ r => Def(y, w, r): Decl }
+
+lazy val Prog: Parser[List[Token], List[Decl]] =
+ (Defn ~ T_SEMI ~ Prog) ==> { case x ~ _ ~ z => x :: z : List[Decl] } ||
+ (Exp ==> ((s) => List(Main(s)) : List[Decl]))
+
+
+// compiler - built-in functions
+// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
+//
+
+val library = """
+.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
+ invokevirtual java/io/PrintStream/println(I)V
+ return
+.end method
+
+"""
+
+// calculating the maximal needed stack size
+def max_stack_exp(e: Exp): Int = e match {
+ case Call(_, args) => args.map(max_stack_exp).sum
+ case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
+ case Write(e) => max_stack_exp(e) + 1
+ case Var(_) => 1
+ case Num(_) => 1
+ case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+ case Sequence(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
+}
+def max_stack_bexp(e: BExp): Int = e match {
+ case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
+}
+
+
+// for generating new labels
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+// convenient string interpolations
+// for instructions, labels and methods
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+implicit def sring_inters(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
+ def m(args: Any*): String = sc.s(args:_*) ++ "\n"
+}
+
+
+type Env = Map[String, Int]
+
+
+def compile_expT(a: Exp, env : Env, name: String) : String = a match {
+ case Num(i) => i"ldc $i"
+ case Var(s) => i"iload ${env(s)}"
+ case Aop("+", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"iadd"
+ case Aop("-", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"isub"
+ case Aop("*", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"imul"
+ case Aop("/", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"idiv"
+ case Aop("%", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"irem"
+ case If(b, a1, a2) => {
+ val if_else = Fresh("If_else")
+ val if_end = Fresh("If_end")
+ compile_bexpT(b, env, if_else) ++
+ compile_expT(a1, env, name) ++
+ i"goto $if_end" ++
+ l"$if_else" ++
+ compile_expT(a2, env, name) ++
+ l"$if_end"
+ }
+ case Call(n, args) => if (name == n) {
+ val stores = args.zipWithIndex.map { case (x, y) => i"istore $y" }
+ args.map(a => compile_expT(a, env, "")).mkString ++
+ stores.reverse.mkString ++
+ i"goto ${n}_Start"
+ } else {
+ val is = "I" * args.length
+ args.map(a => compile_expT(a, env, "")).mkString ++
+ i"invokestatic XXX/XXX/${n}(${is})I"
+ }
+ case Sequence(a1, a2) => {
+ compile_expT(a1, env, "") ++ i"pop" ++ compile_expT(a2, env, name)
+ }
+ case Write(a1) => {
+ compile_expT(a1, env, "") ++
+ i"dup" ++
+ i"invokestatic XXX/XXX/write(I)V"
+ }
+}
+
+def compile_bexpT(b: BExp, env : Env, jmp: String) : String = b match {
+ case Bop("==", a1, a2) =>
+ compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpne $jmp"
+ case Bop("!=", a1, a2) =>
+ compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpeq $jmp"
+ case Bop("<", a1, a2) =>
+ compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpge $jmp"
+ case Bop("<=", a1, a2) =>
+ compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpgt $jmp"
+}
+
+
+def compile_decl(d: Decl) : String = d match {
+ case Def(name, args, a) => {
+ val env = args.zipWithIndex.toMap
+ val is = "I" * args.length
+ m".method public static $name($is)I" ++
+ m".limit locals ${args.length}" ++
+ m".limit stack ${1 + max_stack_exp(a)}" ++
+ l"${name}_Start" ++
+ compile_expT(a, env, name) ++
+ i"ireturn" ++
+ m".end method\n"
+ }
+ case Main(a) => {
+ m".method public static main([Ljava/lang/String;)V" ++
+ m".limit locals 200" ++
+ m".limit stack 200" ++
+ compile_expT(a, Map(), "") ++
+ i"invokestatic XXX/XXX/write(I)V" ++
+ i"return\n" ++
+ m".end method\n"
+ }
+}
+
+// main compiler functions
+
+def time_needed[T](i: Int, code: => T) = {
+ val start = System.nanoTime()
+ for (j <- 1 to i) code
+ val end = System.nanoTime()
+ (end - start)/(i * 1.0e9)
+}
+
+def compile(class_name: String, input: String) : String = {
+ val tks = tokenise(input)
+ val ast = Prog.parse_single(tks)
+ val instructions = ast.map(compile_decl).mkString
+ (library + instructions).replaceAllLiterally("XXX", class_name)
+}
+
+def compile_file(class_name: String) = {
+ val input = io.Source.fromFile(s"${class_name}.fun").mkString
+ val output = compile(class_name, input)
+ scala.tools.nsc.io.File(s"${class_name}.j").writeAll(output)
+}
+
+import scala.sys.process._
+
+def compile_run(class_name: String) : Unit = {
+ compile_file(class_name)
+ (s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
+ println("Time: " + time_needed(2, (s"java ${class_name}/${class_name}").!))
+}
+
+
+//examples
+compile_run("defs")
+compile_run("fact")
--- a/progs/fun_llvm.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,290 +0,0 @@
-// A Small LLVM Compiler for a Simple Functional Language
-// (includes an external lexer and parser)
-//
-// call with
-//
-// scala fun_llvm.scala fact
-//
-// scala fun_llvm.scala defs
-//
-// this will generate a .ll file. You can interpret this file
-// using lli.
-//
-// The optimiser can be invoked as
-//
-// opt -O1 -S in_file.ll > out_file.ll
-// opt -O3 -S in_file.ll > out_file.ll
-//
-// The code produced for the various architectures can be obtains with
-//
-// llc -march=x86 -filetype=asm in_file.ll -o -
-// llc -march=arm -filetype=asm in_file.ll -o -
-//
-// Producing an executable can be achieved by
-//
-// llc -filetype=obj in_file.ll
-// gcc in_file.o -o a.out
-// ./a.out
-
-
-
-object Compiler {
-
-import java.io._
-import scala.util._
-import scala.sys.process._
-
-// Abstract syntax trees for the Fun language
-abstract class Exp extends Serializable
-abstract class BExp extends Serializable
-abstract class Decl extends Serializable
-
-case class Def(name: String, args: List[String], body: Exp) extends Decl
-case class Main(e: Exp) extends Decl
-
-case class Call(name: String, args: List[Exp]) extends Exp
-case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
-case class Write(e: Exp) extends Exp
-case class Var(s: String) extends Exp
-case class Num(i: Int) extends Exp
-case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
-case class Sequence(e1: Exp, e2: Exp) extends Exp
-case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
-
-
-// for generating new labels
-var counter = -1
-
-def Fresh(x: String) = {
- counter += 1
- x ++ "_" ++ counter.toString()
-}
-
-// Internal CPS language for FUN
-abstract class KExp
-abstract class KVal
-
-case class KVar(s: String) extends KVal
-case class KNum(i: Int) extends KVal
-case class Kop(o: String, v1: KVal, v2: KVal) extends KVal
-case class KCall(o: String, vrs: List[KVal]) extends KVal
-case class KWrite(v: KVal) extends KVal
-
-case class KIf(x1: String, e1: KExp, e2: KExp) extends KExp {
- override def toString = s"KIf $x1\nIF\n$e1\nELSE\n$e2"
-}
-case class KLet(x: String, e1: KVal, e2: KExp) extends KExp {
- override def toString = s"let $x = $e1 in \n$e2"
-}
-case class KReturn(v: KVal) extends KExp
-
-
-// CPS translation from Exps to KExps using a
-// continuation k.
-def CPS(e: Exp)(k: KVal => KExp) : KExp = e match {
- case Var(s) => k(KVar(s))
- case Num(i) => k(KNum(i))
- case Aop(o, e1, e2) => {
- val z = Fresh("tmp")
- CPS(e1)(y1 =>
- CPS(e2)(y2 => KLet(z, Kop(o, y1, y2), k(KVar(z)))))
- }
- case If(Bop(o, b1, b2), e1, e2) => {
- val z = Fresh("tmp")
- CPS(b1)(y1 =>
- CPS(b2)(y2 =>
- KLet(z, Kop(o, y1, y2), KIf(z, CPS(e1)(k), CPS(e2)(k)))))
- }
- case Call(name, args) => {
- def aux(args: List[Exp], vs: List[KVal]) : KExp = args match {
- case Nil => {
- val z = Fresh("tmp")
- KLet(z, KCall(name, vs), k(KVar(z)))
- }
- case e::es => CPS(e)(y => aux(es, vs ::: List(y)))
- }
- aux(args, Nil)
- }
- case Sequence(e1, e2) =>
- CPS(e1)(_ => CPS(e2)(y2 => k(y2)))
- case Write(e) => {
- val z = Fresh("tmp")
- CPS(e)(y => KLet(z, KWrite(y), k(KVar(z))))
- }
-}
-
-//initial continuation
-def CPSi(e: Exp) = CPS(e)(KReturn)
-
-// some testcases
-val e1 = Aop("*", Var("a"), Num(3))
-CPSi(e1)
-
-val e2 = Aop("+", Aop("*", Var("a"), Num(3)), Num(4))
-CPSi(e2)
-
-val e3 = Aop("+", Num(2), Aop("*", Var("a"), Num(3)))
-CPSi(e3)
-
-val e4 = Aop("+", Aop("-", Num(1), Num(2)), Aop("*", Var("a"), Num(3)))
-CPSi(e4)
-
-val e5 = If(Bop("==", Num(1), Num(1)), Num(3), Num(4))
-CPSi(e5)
-
-val e6 = If(Bop("!=", Num(10), Num(10)), e5, Num(40))
-CPSi(e6)
-
-val e7 = Call("foo", List(Num(3)))
-CPSi(e7)
-
-val e8 = Call("foo", List(Aop("*", Num(3), Num(1)), Num(4), Aop("+", Num(5), Num(6))))
-CPSi(e8)
-
-val e9 = Sequence(Aop("*", Var("a"), Num(3)), Aop("+", Var("b"), Num(6)))
-CPSi(e9)
-
-val e = Aop("*", Aop("+", Num(1), Call("foo", List(Var("a"), Num(3)))), Num(4))
-CPSi(e)
-
-
-
-
-// convenient string interpolations
-// for instructions, labels and methods
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-implicit def sring_inters(sc: StringContext) = new {
- def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
- def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
- def m(args: Any*): String = sc.s(args:_*) ++ "\n"
-}
-
-// mathematical and boolean operations
-def compile_op(op: String) = op match {
- case "+" => "add i32 "
- case "*" => "mul i32 "
- case "-" => "sub i32 "
- case "/" => "sdiv i32 "
- case "%" => "srem i32 "
- case "==" => "icmp eq i32 "
- case "<=" => "icmp sle i32 " // signed less or equal
- case "<" => "icmp slt i32 " // signed less than
-}
-
-def compile_val(v: KVal) : String = v match {
- case KNum(i) => s"$i"
- case KVar(s) => s"%$s"
- case Kop(op, x1, x2) =>
- s"${compile_op(op)} ${compile_val(x1)}, ${compile_val(x2)}"
- case KCall(x1, args) =>
- s"call i32 @$x1 (${args.map(compile_val).mkString("i32 ", ", i32 ", "")})"
- case KWrite(x1) =>
- s"call i32 @printInt (i32 ${compile_val(x1)})"
-}
-
-// compile K expressions
-def compile_exp(a: KExp) : String = a match {
- case KReturn(v) =>
- i"ret i32 ${compile_val(v)}"
- case KLet(x: String, v: KVal, e: KExp) =>
- i"%$x = ${compile_val(v)}" ++ compile_exp(e)
- case KIf(x, e1, e2) => {
- val if_br = Fresh("if_branch")
- val else_br = Fresh("else_branch")
- i"br i1 %$x, label %$if_br, label %$else_br" ++
- l"\n$if_br" ++
- compile_exp(e1) ++
- l"\n$else_br" ++
- compile_exp(e2)
- }
-}
-
-
-val prelude = """
-@.str = private constant [4 x i8] c"%d\0A\00"
-
-declare i32 @printf(i8*, ...)
-
-define i32 @printInt(i32 %x) {
- %t0 = getelementptr [4 x i8], [4 x i8]* @.str, i32 0, i32 0
- call i32 (i8*, ...) @printf(i8* %t0, i32 %x)
- ret i32 %x
-}
-
-"""
-
-
-// compile function for declarations and main
-def compile_decl(d: Decl) : String = d match {
- case Def(name, args, body) => {
- m"define i32 @$name (${args.mkString("i32 %", ", i32 %", "")}) {" ++
- compile_exp(CPSi(body)) ++
- m"}\n"
- }
- case Main(body) => {
- m"define i32 @main() {" ++
- compile_exp(CPSi(body)) ++
- m"}\n"
- }
-}
-
-// main compiler functions
-
-def time_needed[T](i: Int, code: => T) = {
- val start = System.nanoTime()
- for (j <- 1 to i) code
- val end = System.nanoTime()
- (end - start)/(i * 1.0e9)
-}
-
-// for Scala 2.12
-/*
-def deserialise[T](file: String) : Try[T] = {
- val in = new ObjectInputStream(new FileInputStream(new File(file)))
- val obj = Try(in.readObject().asInstanceOf[T])
- in.close()
- obj
-}
-*/
-
-def deserialise[T](fname: String) : Try[T] = {
- import scala.util.Using
- Using(new ObjectInputStream(new FileInputStream(fname))) {
- in => in.readObject.asInstanceOf[T]
- }
-}
-
-def compile(fname: String) : String = {
- val ast = deserialise[List[Decl]](fname ++ ".prs").getOrElse(Nil)
- prelude ++ (ast.map(compile_decl).mkString)
-}
-
-def compile_to_file(fname: String) = {
- val output = compile(fname)
- scala.tools.nsc.io.File(s"${fname}.ll").writeAll(output)
-}
-
-def compile_and_run(fname: String) : Unit = {
- compile_to_file(fname)
- (s"llc -filetype=obj ${fname}.ll").!!
- (s"gcc ${fname}.o -o a.out").!!
- println("Time: " + time_needed(2, (s"./a.out").!))
-}
-
-// some examples of .fun files
-//compile_to_file("fact")
-//compile_and_run("fact")
-//compile_and_run("defs")
-
-
-def main(args: Array[String]) : Unit =
- //println(compile(args(0)))
- compile_and_run(args(0))
-}
-
-
-
-
-
--- a/progs/fun_parser.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,199 +0,0 @@
-// A parser for the Fun language
-//================================
-//
-// call with
-//
-// scala fun_parser.scala fact.tks
-//
-// scala fun_parser.scala defs.tks
-//
-// this will generate a .prs file that can be deserialised back
-// into a list of declarations
-
-object Fun_Parser {
-
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-import scala.util._
-import java.io._
-
-abstract class Token extends Serializable
-case object T_SEMI extends Token
-case object T_COMMA extends Token
-case object T_LPAREN extends Token
-case object T_RPAREN extends Token
-case class T_ID(s: String) extends Token
-case class T_OP(s: String) extends Token
-case class T_NUM(n: Int) extends Token
-case class T_KWD(s: String) extends Token
-
-
-// Parser combinators
-// type parameter I needs to be of Seq-type
-//
-abstract class Parser[I, T](implicit ev: I => Seq[_]) {
- def parse(ts: I): Set[(T, I)]
-
- def parse_single(ts: I) : T =
- parse(ts).partition(_._2.isEmpty) match {
- case (good, _) if !good.isEmpty => good.head._1
- case (_, err) => {
- println (s"Parse Error\n${err.minBy(_._2.length)}") ; sys.exit(-1) }
- }
-}
-
-// convenience for writing grammar rules
-case class ~[+A, +B](_1: A, _2: B)
-
-class SeqParser[I, T, S](p: => Parser[I, T],
- q: => Parser[I, S])(implicit ev: I => Seq[_]) extends Parser[I, ~[T, S]] {
- def parse(sb: I) =
- for ((head1, tail1) <- p.parse(sb);
- (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
-}
-
-class AltParser[I, T](p: => Parser[I, T],
- q: => Parser[I, T])(implicit ev: I => Seq[_]) extends Parser[I, T] {
- def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
-}
-
-class FunParser[I, T, S](p: => Parser[I, T],
- f: T => S)(implicit ev: I => Seq[_]) extends Parser[I, S] {
- def parse(sb: I) =
- for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-// convenient combinators
-implicit def ParserOps[I, T](p: Parser[I, T])(implicit ev: I => Seq[_]) = new {
- def || (q : => Parser[I, T]) = new AltParser[I, T](p, q)
- def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
- def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-}
-
-def ListParser[I, T, S](p: => Parser[I, T],
- q: => Parser[I, S])(implicit ev: I => Seq[_]): Parser[I, List[T]] = {
- (p ~ q ~ ListParser(p, q)) ==> { case x ~ _ ~ z => x :: z : List[T] } ||
- (p ==> ((s) => List(s)))
-}
-
-case class TokParser(tok: Token) extends Parser[List[Token], Token] {
- def parse(ts: List[Token]) = ts match {
- case t::ts if (t == tok) => Set((t, ts))
- case _ => Set ()
- }
-}
-
-implicit def token2tparser(t: Token) = TokParser(t)
-
-implicit def TokOps(t: Token) = new {
- def || (q : => Parser[List[Token], Token]) = new AltParser[List[Token], Token](t, q)
- def ==>[S] (f: => Token => S) = new FunParser[List[Token], Token, S](t, f)
- def ~[S](q : => Parser[List[Token], S]) = new SeqParser[List[Token], Token, S](t, q)
-}
-
-case object NumParser extends Parser[List[Token], Int] {
- def parse(ts: List[Token]) = ts match {
- case T_NUM(n)::ts => Set((n, ts))
- case _ => Set ()
- }
-}
-
-case object IdParser extends Parser[List[Token], String] {
- def parse(ts: List[Token]) = ts match {
- case T_ID(s)::ts => Set((s, ts))
- case _ => Set ()
- }
-}
-
-
-
-// Abstract syntax trees for the Fun language
-abstract class Exp extends Serializable
-abstract class BExp extends Serializable
-abstract class Decl extends Serializable
-
-case class Def(name: String, args: List[String], body: Exp) extends Decl
-case class Main(e: Exp) extends Decl
-
-case class Call(name: String, args: List[Exp]) extends Exp
-case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
-case class Write(e: Exp) extends Exp
-case class Var(s: String) extends Exp
-case class Num(i: Int) extends Exp
-case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
-case class Sequence(e1: Exp, e2: Exp) extends Exp
-case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
-
-
-
-// Grammar Rules for the Fun language
-
-// arithmetic expressions
-lazy val Exp: Parser[List[Token], Exp] =
- (T_KWD("if") ~ BExp ~ T_KWD("then") ~ Exp ~ T_KWD("else") ~ Exp) ==>
- { case _ ~ x ~ _ ~ y ~ _ ~ z => If(x, y, z): Exp } ||
- (M ~ T_SEMI ~ Exp) ==> { case x ~ _ ~ y => Sequence(x, y): Exp } || M
-lazy val M: Parser[List[Token], Exp] =
- (T_KWD("write") ~ L) ==> { case _ ~ y => Write(y): Exp } || L
-lazy val L: Parser[List[Token], Exp] =
- (T ~ T_OP("+") ~ Exp) ==> { case x ~ _ ~ z => Aop("+", x, z): Exp } ||
- (T ~ T_OP("-") ~ Exp) ==> { case x ~ _ ~ z => Aop("-", x, z): Exp } || T
-lazy val T: Parser[List[Token], Exp] =
- (F ~ T_OP("*") ~ T) ==> { case x ~ _ ~ z => Aop("*", x, z): Exp } ||
- (F ~ T_OP("/") ~ T) ==> { case x ~ _ ~ z => Aop("/", x, z): Exp } ||
- (F ~ T_OP("%") ~ T) ==> { case x ~ _ ~ z => Aop("%", x, z): Exp } || F
-lazy val F: Parser[List[Token], Exp] =
- (IdParser ~ T_LPAREN ~ ListParser(Exp, T_COMMA) ~ T_RPAREN) ==>
- { case x ~ _ ~ z ~ _ => Call(x, z): Exp } ||
- (T_LPAREN ~ Exp ~ T_RPAREN) ==> { case _ ~ y ~ _ => y: Exp } ||
- IdParser ==> { case x => Var(x): Exp } ||
- NumParser ==> { case x => Num(x): Exp }
-
-// boolean expressions
-lazy val BExp: Parser[List[Token], BExp] =
- (Exp ~ T_OP("==") ~ Exp) ==> { case x ~ _ ~ z => Bop("==", x, z): BExp } ||
- (Exp ~ T_OP("!=") ~ Exp) ==> { case x ~ _ ~ z => Bop("!=", x, z): BExp } ||
- (Exp ~ T_OP("<") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", x, z): BExp } ||
- (Exp ~ T_OP(">") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", z, x): BExp } ||
- (Exp ~ T_OP("<=") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", x, z): BExp } ||
- (Exp ~ T_OP("=>") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", z, x): BExp }
-
-lazy val Defn: Parser[List[Token], Decl] =
- (T_KWD("def") ~ IdParser ~ T_LPAREN ~ ListParser(IdParser, T_COMMA) ~ T_RPAREN ~ T_OP("=") ~ Exp) ==>
- { case _ ~ y ~ _ ~ w ~ _ ~ _ ~ r => Def(y, w, r): Decl }
-
-lazy val Prog: Parser[List[Token], List[Decl]] =
- (Defn ~ T_SEMI ~ Prog) ==> { case x ~ _ ~ z => x :: z : List[Decl] } ||
- (Exp ==> ((s) => List(Main(s)) : List[Decl]))
-
-
-
-// Reading tokens and Writing parse trees
-
-def serialise[T](fname: String, data: T) = {
- import scala.util.Using
- Using(new ObjectOutputStream(new FileOutputStream(fname))) {
- out => out.writeObject(data)
- }
-}
-
-def deserialise[T](fname: String) : Try[T] = {
- import scala.util.Using
- Using(new ObjectInputStream(new FileInputStream(fname))) {
- in => in.readObject.asInstanceOf[T]
- }
-}
-
-
-def main(args: Array[String]) : Unit= {
- val fname = args(0)
- val pname = fname.stripSuffix(".tks") ++ ".prs"
- val tks = deserialise[List[Token]](fname).getOrElse(Nil)
- serialise(pname, Prog.parse_single(tks))
-
- // testing whether read-back is working
- //val ptree = deserialise[List[Decl]](pname).get
- //println(s"Reading back from ${pname}:\n${ptree.mkString("\n")}")
-}
-
-}
--- a/progs/fun_tokens.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,273 +0,0 @@
-// A tokeniser for the Fun language
-//==================================
-//
-// call with
-//
-// scala fun_tokens.scala fact.fun
-//
-// scala fun_tokens.scala defs.fun
-//
-// this will generate a .tks file that can be deserialised back
-// into a list of tokens
-// you can add -Xno-patmat-analysis in order to get rid of the
-// match-not-exhaustive warning
-
-object Fun_Tokens {
-
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-abstract class Rexp
-case object ZERO extends Rexp
-case object ONE 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 Empty 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
-
-// some convenience for typing in regular expressions
-def charlist2rexp(s : List[Char]): Rexp = s match {
- case Nil => ONE
- case c::Nil => CHAR(c)
- case c::s => SEQ(CHAR(c), charlist2rexp(s))
-}
-implicit def string2rexp(s : String) : Rexp =
- charlist2rexp(s.toList)
-
-implicit def RexpOps(r: Rexp) = new {
- def | (s: Rexp) = ALT(r, s)
- def % = STAR(r)
- def ~ (s: Rexp) = SEQ(r, s)
-}
-
-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)
-}
-
-def nullable (r: Rexp) : Boolean = r match {
- case ZERO => false
- case ONE => 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)
-}
-
-def der (c: Char, r: Rexp) : Rexp = r match {
- case ZERO => ZERO
- case ONE => ZERO
- case CHAR(d) => if (c == d) ONE else ZERO
- 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)
-}
-
-
-// extracts a string from value
-def flatten(v: Val) : String = v match {
- case Empty => ""
- 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)
-}
-
-// extracts an environment from a value;
-// used for tokenise a string
-def env(v: Val) : List[(String, String)] = v match {
- case Empty => 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)
-}
-
-// The Injection Part of the lexer
-
-def mkeps(r: Rexp) : Val = r match {
- case ONE => Empty
- 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))
-}
-
-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), Empty) => Chr(c)
- case (RECD(x, r1), _) => Rec(x, inj(r1, c, v))
- case _ => { println ("Injection error") ; sys.exit(-1) }
-}
-
-// some "rectification" functions for simplification
-def F_ID(v: Val): Val = v
-def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))
-def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))
-def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
- case Right(v) => Right(f2(v))
- case Left(v) => Left(f1(v))
-}
-def F_SEQ(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
- case Sequ(v1, v2) => Sequ(f1(v1), f2(v2))
-}
-def F_SEQ_Empty1(f1: Val => Val, f2: Val => Val) =
- (v:Val) => Sequ(f1(Empty), f2(v))
-def F_SEQ_Empty2(f1: Val => Val, f2: Val => Val) =
- (v:Val) => Sequ(f1(v), f2(Empty))
-def F_RECD(f: Val => Val) = (v:Val) => v match {
- case Rec(x, v) => Rec(x, f(v))
-}
-def F_ERROR(v: Val): Val = throw new Exception("error")
-
-def simp(r: Rexp): (Rexp, Val => Val) = r match {
- case ALT(r1, r2) => {
- val (r1s, f1s) = simp(r1)
- val (r2s, f2s) = simp(r2)
- (r1s, r2s) match {
- case (ZERO, _) => (r2s, F_RIGHT(f2s))
- case (_, ZERO) => (r1s, F_LEFT(f1s))
- case _ => if (r1s == r2s) (r1s, F_LEFT(f1s))
- else (ALT (r1s, r2s), F_ALT(f1s, f2s))
- }
- }
- case SEQ(r1, r2) => {
- val (r1s, f1s) = simp(r1)
- val (r2s, f2s) = simp(r2)
- (r1s, r2s) match {
- case (ZERO, _) => (ZERO, F_ERROR)
- case (_, ZERO) => (ZERO, F_ERROR)
- case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))
- case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))
- case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))
- }
- }
- case RECD(x, r1) => {
- val (r1s, f1s) = simp(r1)
- (RECD(x, r1s), F_RECD(f1s))
- }
- case r => (r, F_ID)
-}
-
-// lexing functions including simplification
-def lex_simp(r: Rexp, s: List[Char]) : Val = s match {
- case Nil => if (nullable(r)) mkeps(r) else { println ("Lexing Error") ; sys.exit(-1) }
- case c::cs => {
- val (r_simp, f_simp) = simp(der(c, r))
- inj(r, c, f_simp(lex_simp(r_simp, cs)))
- }
-}
-
-def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))
-
-
-// The Lexing Rules for the Fun Language
-
-def PLUS(r: Rexp) = r ~ r.%
-
-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" | "T" | "_"
-val DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
-val ID = SYM ~ (SYM | DIGIT).%
-val NUM = PLUS(DIGIT)
-val KEYWORD : Rexp = "if" | "then" | "else" | "write" | "def"
-val SEMI: Rexp = ";"
-val OP: Rexp = "=" | "==" | "-" | "+" | "*" | "!=" | "<" | ">" | "<=" | ">=" | "%" | "/"
-val WHITESPACE = PLUS(" " | "\n" | "\t")
-val RPAREN: Rexp = ")"
-val LPAREN: Rexp = "("
-val COMMA: Rexp = ","
-val ALL = SYM | DIGIT | OP | " " | ":" | ";" | "\"" | "=" | "," | "(" | ")"
-val ALL2 = ALL | "\n"
-val COMMENT = ("/*" ~ ALL2.% ~ "*/") | ("//" ~ ALL.% ~ "\n")
-
-
-val FUN_REGS = (("k" $ KEYWORD) |
- ("i" $ ID) |
- ("o" $ OP) |
- ("n" $ NUM) |
- ("s" $ SEMI) |
- ("c" $ COMMA) |
- ("pl" $ LPAREN) |
- ("pr" $ RPAREN) |
- ("w" $ (WHITESPACE | COMMENT))).%
-
-
-
-// The tokens for the Fun language
-
-import java.io._
-
-abstract class Token extends Serializable
-case object T_SEMI extends Token
-case object T_COMMA extends Token
-case object T_LPAREN extends Token
-case object T_RPAREN extends Token
-case class T_ID(s: String) extends Token
-case class T_OP(s: String) extends Token
-case class T_NUM(n: Int) extends Token
-case class T_KWD(s: String) extends Token
-
-val token : PartialFunction[(String, String), Token] = {
- case ("k", s) => T_KWD(s)
- case ("i", s) => T_ID(s)
- case ("o", s) => T_OP(s)
- case ("n", s) => T_NUM(s.toInt)
- case ("s", _) => T_SEMI
- case ("c", _) => T_COMMA
- case ("pl", _) => T_LPAREN
- case ("pr", _) => T_RPAREN
-}
-
-
-def tokenise(s: String) : List[Token] = {
- val tks = lexing_simp(FUN_REGS, s).collect(token)
- if (tks.length != 0) tks
- else { println (s"Tokenise Error") ; sys.exit(-1) }
-}
-
-def serialise[T](fname: String, data: T) = {
- import scala.util.Using
- Using(new ObjectOutputStream(new FileOutputStream(fname))) {
- out => out.writeObject(data)
- }
-}
-
-def main(args: Array[String]) : Unit = {
- val fname = args(0)
- val tname = fname.stripSuffix(".fun") ++ ".tks"
- val file = io.Source.fromFile(fname).mkString
- serialise(tname, tokenise(file))
-}
-
-
-}
--- a/progs/funt.scala Sat Jul 04 21:57:33 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,543 +0,0 @@
-// A Small Compiler for a Simple Functional Language
-// (includes a lexer and a parser)
-
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-abstract class Rexp
-case object ZERO extends Rexp
-case object ONE 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 Empty 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
-
-// some convenience for typing in regular expressions
-def charlist2rexp(s : List[Char]): Rexp = s match {
- case Nil => ONE
- case c::Nil => CHAR(c)
- case c::s => SEQ(CHAR(c), charlist2rexp(s))
-}
-implicit def string2rexp(s : String) : Rexp =
- charlist2rexp(s.toList)
-
-implicit def RexpOps(r: Rexp) = new {
- def | (s: Rexp) = ALT(r, s)
- def % = STAR(r)
- def ~ (s: Rexp) = SEQ(r, s)
-}
-
-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)
-}
-
-def nullable (r: Rexp) : Boolean = r match {
- case ZERO => false
- case ONE => 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)
-}
-
-def der (c: Char, r: Rexp) : Rexp = r match {
- case ZERO => ZERO
- case ONE => ZERO
- case CHAR(d) => if (c == d) ONE else ZERO
- 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)
-}
-
-
-// extracts a string from value
-def flatten(v: Val) : String = v match {
- case Empty => ""
- 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)
-}
-
-// extracts an environment from a value;
-// used for tokenise a string
-def env(v: Val) : List[(String, String)] = v match {
- case Empty => 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)
-}
-
-// The Injection Part of the lexer
-
-def mkeps(r: Rexp) : Val = r match {
- case ONE => Empty
- 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))
-}
-
-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), Empty) => Chr(c)
- case (RECD(x, r1), _) => Rec(x, inj(r1, c, v))
- case _ => { println ("Injection error") ; sys.exit(-1) }
-}
-
-// some "rectification" functions for simplification
-def F_ID(v: Val): Val = v
-def F_RIGHT(f: Val => Val) = (v:Val) => Right(f(v))
-def F_LEFT(f: Val => Val) = (v:Val) => Left(f(v))
-def F_ALT(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
- case Right(v) => Right(f2(v))
- case Left(v) => Left(f1(v))
-}
-def F_SEQ(f1: Val => Val, f2: Val => Val) = (v:Val) => v match {
- case Sequ(v1, v2) => Sequ(f1(v1), f2(v2))
-}
-def F_SEQ_Empty1(f1: Val => Val, f2: Val => Val) =
- (v:Val) => Sequ(f1(Empty), f2(v))
-def F_SEQ_Empty2(f1: Val => Val, f2: Val => Val) =
- (v:Val) => Sequ(f1(v), f2(Empty))
-def F_RECD(f: Val => Val) = (v:Val) => v match {
- case Rec(x, v) => Rec(x, f(v))
-}
-def F_ERROR(v: Val): Val = throw new Exception("error")
-
-def simp(r: Rexp): (Rexp, Val => Val) = r match {
- case ALT(r1, r2) => {
- val (r1s, f1s) = simp(r1)
- val (r2s, f2s) = simp(r2)
- (r1s, r2s) match {
- case (ZERO, _) => (r2s, F_RIGHT(f2s))
- case (_, ZERO) => (r1s, F_LEFT(f1s))
- case _ => if (r1s == r2s) (r1s, F_LEFT(f1s))
- else (ALT (r1s, r2s), F_ALT(f1s, f2s))
- }
- }
- case SEQ(r1, r2) => {
- val (r1s, f1s) = simp(r1)
- val (r2s, f2s) = simp(r2)
- (r1s, r2s) match {
- case (ZERO, _) => (ZERO, F_ERROR)
- case (_, ZERO) => (ZERO, F_ERROR)
- case (ONE, _) => (r2s, F_SEQ_Empty1(f1s, f2s))
- case (_, ONE) => (r1s, F_SEQ_Empty2(f1s, f2s))
- case _ => (SEQ(r1s,r2s), F_SEQ(f1s, f2s))
- }
- }
- case RECD(x, r1) => {
- val (r1s, f1s) = simp(r1)
- (RECD(x, r1s), F_RECD(f1s))
- }
- case r => (r, F_ID)
-}
-
-// lexing functions including simplification
-def lex_simp(r: Rexp, s: List[Char]) : Val = s match {
- case Nil => if (nullable(r)) mkeps(r) else { println ("Lexing Error") ; sys.exit(-1) }
- case c::cs => {
- val (r_simp, f_simp) = simp(der(c, r))
- inj(r, c, f_simp(lex_simp(r_simp, cs)))
- }
-}
-
-def lexing_simp(r: Rexp, s: String) = env(lex_simp(r, s.toList))
-
-
-// The Lexing Rules for the Fun Language
-
-def PLUS(r: Rexp) = r ~ r.%
-
-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" | "T" | "_"
-val DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
-val ID = SYM ~ (SYM | DIGIT).%
-val NUM = PLUS(DIGIT)
-val KEYWORD : Rexp = "if" | "then" | "else" | "write" | "def"
-val SEMI: Rexp = ";"
-val OP: Rexp = "=" | "==" | "-" | "+" | "*" | "!=" | "<" | ">" | "<=" | ">=" | "%" | "/"
-val WHITESPACE = PLUS(" " | "\n" | "\t")
-val RPAREN: Rexp = ")"
-val LPAREN: Rexp = "("
-val COMMA: Rexp = ","
-val ALL = SYM | DIGIT | OP | " " | ":" | ";" | "\"" | "=" | "," | "(" | ")"
-val ALL2 = ALL | "\n"
-val COMMENT = ("/*" ~ ALL2.% ~ "*/") | ("//" ~ ALL.% ~ "\n")
-
-
-val WHILE_REGS = (("k" $ KEYWORD) |
- ("i" $ ID) |
- ("o" $ OP) |
- ("n" $ NUM) |
- ("s" $ SEMI) |
- ("c" $ COMMA) |
- ("pl" $ LPAREN) |
- ("pr" $ RPAREN) |
- ("w" $ (WHITESPACE | COMMENT))).%
-
-
-
-// The tokens for the Fun language
-
-abstract class Token
-case object T_SEMI extends Token
-case object T_COMMA extends Token
-case object T_LPAREN extends Token
-case object T_RPAREN extends Token
-case class T_ID(s: String) extends Token
-case class T_OP(s: String) extends Token
-case class T_NUM(n: Int) extends Token
-case class T_KWD(s: String) extends Token
-
-val token : PartialFunction[(String, String), Token] = {
- case ("k", s) => T_KWD(s)
- case ("i", s) => T_ID(s)
- case ("o", s) => T_OP(s)
- case ("n", s) => T_NUM(s.toInt)
- case ("s", _) => T_SEMI
- case ("c", _) => T_COMMA
- case ("pl", _) => T_LPAREN
- case ("pr", _) => T_RPAREN
-}
-
-
-def tokenise(s: String) : List[Token] =
- lexing_simp(WHILE_REGS, s).collect(token)
-
-
-
-// Parser combinators
-abstract class Parser[I, T](implicit ev: I => Seq[_]) {
- def parse(ts: I): Set[(T, I)]
-
- def parse_all(ts: I) : Set[T] =
- for ((head, tail) <- parse(ts); if (tail.isEmpty)) yield head
-
- def parse_single(ts: I) : T = parse_all(ts).toList match {
- case List(t) => t
- case _ => { println ("Parse Error\n") ; sys.exit(-1) }
- }
-}
-
-// convenience for matching later on
-case class ~[+A, +B](_1: A, _2: B)
-
-
-class SeqParser[I, T, S](p: => Parser[I, T],
- q: => Parser[I, S])(implicit ev: I => Seq[_]) extends Parser[I, ~[T, S]] {
- def parse(sb: I) =
- for ((head1, tail1) <- p.parse(sb);
- (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
-}
-
-class AltParser[I, T](p: => Parser[I, T],
- q: => Parser[I, T])(implicit ev: I => Seq[_]) extends Parser[I, T] {
- def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
-}
-
-class FunParser[I, T, S](p: => Parser[I, T],
- f: T => S)(implicit ev: I => Seq[_]) extends Parser[I, S] {
- def parse(sb: I) =
- for ((head, tail) <- p.parse(sb)) yield (f(head), tail)
-}
-
-implicit def ParserOps[I, T](p: Parser[I, T])(implicit ev: I => Seq[_]) = new {
- def || (q : => Parser[I, T]) = new AltParser[I, T](p, q)
- def ==>[S] (f: => T => S) = new FunParser[I, T, S](p, f)
- def ~[S] (q : => Parser[I, S]) = new SeqParser[I, T, S](p, q)
-}
-
-def ListParser[I, T, S](p: => Parser[I, T],
- q: => Parser[I, S])(implicit ev: I => Seq[_]): Parser[I, List[T]] = {
- (p ~ q ~ ListParser(p, q)) ==> { case x ~ _ ~ z => x :: z : List[T] } ||
- (p ==> ((s) => List(s)))
-}
-
-case class TokParser(tok: Token) extends Parser[List[Token], Token] {
- def parse(ts: List[Token]) = ts match {
- case t::ts if (t == tok) => Set((t, ts))
- case _ => Set ()
- }
-}
-
-implicit def token2tparser(t: Token) = TokParser(t)
-
-implicit def TokOps(t: Token) = new {
- def || (q : => Parser[List[Token], Token]) = new AltParser[List[Token], Token](t, q)
- def ==>[S] (f: => Token => S) = new FunParser[List[Token], Token, S](t, f)
- def ~[S](q : => Parser[List[Token], S]) = new SeqParser[List[Token], Token, S](t, q)
-}
-
-case object NumParser extends Parser[List[Token], Int] {
- def parse(ts: List[Token]) = ts match {
- case T_NUM(n)::ts => Set((n, ts))
- case _ => Set ()
- }
-}
-
-case object IdParser extends Parser[List[Token], String] {
- def parse(ts: List[Token]) = ts match {
- case T_ID(s)::ts => Set((s, ts))
- case _ => Set ()
- }
-}
-
-
-
-// Abstract syntax trees for Fun
-abstract class Exp
-abstract class BExp
-abstract class Decl
-
-case class Def(name: String, args: List[String], body: Exp) extends Decl
-case class Main(e: Exp) extends Decl
-
-case class Call(name: String, args: List[Exp]) extends Exp
-case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
-case class Write(e: Exp) extends Exp
-case class Var(s: String) extends Exp
-case class Num(i: Int) extends Exp
-case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
-case class Sequence(e1: Exp, e2: Exp) extends Exp
-case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
-
-
-
-// Grammar Rules for Fun
-
-// arithmetic expressions
-lazy val Exp: Parser[List[Token], Exp] =
- (T_KWD("if") ~ BExp ~ T_KWD("then") ~ Exp ~ T_KWD("else") ~ Exp) ==>
- { case _ ~ y ~ _ ~ u ~ _ ~ w => If(y, u, w): Exp } ||
- (M ~ T_SEMI ~ Exp) ==> { case x ~ _ ~ z => Sequence(x, z): Exp } || M
-lazy val M: Parser[List[Token], Exp] =
- (T_KWD("write") ~ L) ==> { case _ ~ y => Write(y): Exp } || L
-lazy val L: Parser[List[Token], Exp] =
- (T ~ T_OP("+") ~ Exp) ==> { case x ~ _ ~ z => Aop("+", x, z): Exp } ||
- (T ~ T_OP("-") ~ Exp) ==> { case x ~ _ ~ z => Aop("-", x, z): Exp } || T
-lazy val T: Parser[List[Token], Exp] =
- (F ~ T_OP("*") ~ T) ==> { case x ~ _ ~ z => Aop("*", x, z): Exp } ||
- (F ~ T_OP("/") ~ T) ==> { case x ~ _ ~ z => Aop("/", x, z): Exp } ||
- (F ~ T_OP("%") ~ T) ==> { case x ~ _ ~ z => Aop("%", x, z): Exp } || F
-lazy val F: Parser[List[Token], Exp] =
- (IdParser ~ T_LPAREN ~ ListParser(Exp, T_COMMA) ~ T_RPAREN) ==>
- { case x ~ _ ~ z ~ _ => Call(x, z): Exp } ||
- (T_LPAREN ~ Exp ~ T_RPAREN) ==> { case _ ~ y ~ _ => y: Exp } ||
- IdParser ==> { case x => Var(x): Exp } ||
- NumParser ==> { case x => Num(x): Exp }
-
-// boolean expressions
-lazy val BExp: Parser[List[Token], BExp] =
- (Exp ~ T_OP("==") ~ Exp) ==> { case x ~ _ ~ z => Bop("==", x, z): BExp } ||
- (Exp ~ T_OP("!=") ~ Exp) ==> { case x ~ _ ~ z => Bop("!=", x, z): BExp } ||
- (Exp ~ T_OP("<") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", x, z): BExp } ||
- (Exp ~ T_OP(">") ~ Exp) ==> { case x ~ _ ~ z => Bop("<", z, x): BExp } ||
- (Exp ~ T_OP("<=") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", x, z): BExp } ||
- (Exp ~ T_OP("=>") ~ Exp) ==> { case x ~ _ ~ z => Bop("<=", z, x): BExp }
-
-lazy val Defn: Parser[List[Token], Decl] =
- (T_KWD("def") ~ IdParser ~ T_LPAREN ~ ListParser(IdParser, T_COMMA) ~ T_RPAREN ~ T_OP("=") ~ Exp) ==>
- { case x ~ y ~ z ~ w ~ u ~ v ~ r => Def(y, w, r): Decl }
-
-lazy val Prog: Parser[List[Token], List[Decl]] =
- (Defn ~ T_SEMI ~ Prog) ==> { case x ~ _ ~ z => x :: z : List[Decl] } ||
- (Exp ==> ((s) => List(Main(s)) : List[Decl]))
-
-
-// compiler - built-in functions
-// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
-//
-
-val library = """
-.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
- invokevirtual java/io/PrintStream/println(I)V
- return
-.end method
-
-"""
-
-// calculating the maximal needed stack size
-def max_stack_exp(e: Exp): Int = e match {
- case Call(_, args) => args.map(max_stack_exp).sum
- case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
- case Write(e) => max_stack_exp(e) + 1
- case Var(_) => 1
- case Num(_) => 1
- case Aop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
- case Sequence(e1, e2) => List(max_stack_exp(e1), max_stack_exp(e2)).max
-}
-def max_stack_bexp(e: BExp): Int = e match {
- case Bop(_, a1, a2) => max_stack_exp(a1) + max_stack_exp(a2)
-}
-
-
-// for generating new labels
-var counter = -1
-
-def Fresh(x: String) = {
- counter += 1
- x ++ "_" ++ counter.toString()
-}
-
-// convenient string interpolations
-// for instructions, labels and methods
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-
-implicit def sring_inters(sc: StringContext) = new {
- def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
- def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
- def m(args: Any*): String = sc.s(args:_*) ++ "\n"
-}
-
-
-type Env = Map[String, Int]
-
-
-def compile_expT(a: Exp, env : Env, name: String) : String = a match {
- case Num(i) => i"ldc $i"
- case Var(s) => i"iload ${env(s)}"
- case Aop("+", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"iadd"
- case Aop("-", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"isub"
- case Aop("*", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"imul"
- case Aop("/", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"idiv"
- case Aop("%", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"irem"
- case If(b, a1, a2) => {
- val if_else = Fresh("If_else")
- val if_end = Fresh("If_end")
- compile_bexpT(b, env, if_else) ++
- compile_expT(a1, env, name) ++
- i"goto $if_end" ++
- l"$if_else" ++
- compile_expT(a2, env, name) ++
- l"$if_end"
- }
- case Call(n, args) => if (name == n) {
- val stores = args.zipWithIndex.map { case (x, y) => i"istore $y" }
- args.map(a => compile_expT(a, env, "")).mkString ++
- stores.reverse.mkString ++
- i"goto ${n}_Start"
- } else {
- val is = "I" * args.length
- args.map(a => compile_expT(a, env, "")).mkString ++
- i"invokestatic XXX/XXX/${n}(${is})I"
- }
- case Sequence(a1, a2) => {
- compile_expT(a1, env, "") ++ i"pop" ++ compile_expT(a2, env, name)
- }
- case Write(a1) => {
- compile_expT(a1, env, "") ++
- i"dup" ++
- i"invokestatic XXX/XXX/write(I)V"
- }
-}
-
-def compile_bexpT(b: BExp, env : Env, jmp: String) : String = b match {
- case Bop("==", a1, a2) =>
- compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpne $jmp"
- case Bop("!=", a1, a2) =>
- compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpeq $jmp"
- case Bop("<", a1, a2) =>
- compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpge $jmp"
- case Bop("<=", a1, a2) =>
- compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"if_icmpgt $jmp"
-}
-
-
-def compile_decl(d: Decl) : String = d match {
- case Def(name, args, a) => {
- val env = args.zipWithIndex.toMap
- val is = "I" * args.length
- m".method public static $name($is)I" ++
- m".limit locals ${args.length}" ++
- m".limit stack ${1 + max_stack_exp(a)}" ++
- l"${name}_Start" ++
- compile_expT(a, env, name) ++
- i"ireturn" ++
- m".end method\n"
- }
- case Main(a) => {
- m".method public static main([Ljava/lang/String;)V" ++
- m".limit locals 200" ++
- m".limit stack 200" ++
- compile_expT(a, Map(), "") ++
- i"invokestatic XXX/XXX/write(I)V" ++
- i"return\n" ++
- m".end method\n"
- }
-}
-
-// main compiler functions
-
-def time_needed[T](i: Int, code: => T) = {
- val start = System.nanoTime()
- for (j <- 1 to i) code
- val end = System.nanoTime()
- (end - start)/(i * 1.0e9)
-}
-
-def compile(class_name: String, input: String) : String = {
- val tks = tokenise(input)
- val ast = Prog.parse_single(tks)
- val instructions = ast.map(compile_decl).mkString
- (library + instructions).replaceAllLiterally("XXX", class_name)
-}
-
-def compile_file(class_name: String) = {
- val input = io.Source.fromFile(s"${class_name}.fun").mkString
- val output = compile(class_name, input)
- scala.tools.nsc.io.File(s"${class_name}.j").writeAll(output)
-}
-
-import scala.sys.process._
-
-def compile_run(class_name: String) : Unit = {
- compile_file(class_name)
- (s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
- println("Time: " + time_needed(2, (s"java ${class_name}/${class_name}").!))
-}
-
-
-//examples
-compile_run("defs")
-compile_run("fact")