diff -r f5214da1976e -r 8067d0a8ba04 progs/fun.scala --- a/progs/fun.scala Sun Jul 28 21:10:39 2019 +0100 +++ b/progs/fun.scala Tue Jul 30 20:19:40 2019 +0100 @@ -252,11 +252,13 @@ } } +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)] { + 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 ((head1, head2), tail2) + (head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2) } class AltParser[I, T](p: => Parser[I, T], @@ -278,7 +280,7 @@ 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, y), z) => x :: z : List[T] } || + (p ~ q ~ ListParser(p, q)) ==> { case x ~ _ ~ z => x :: z : List[T] } || (p ==> ((s) => List(s))) } @@ -337,39 +339,39 @@ // 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), u), v), w) => If(y, u, w): Exp } || - (M ~ T_SEMI ~ Exp) ==> { case ((x, y), z) => Sequence(x, z): Exp } || M + { 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 (x, y) => Write(y): Exp } || L + (T_KWD("write") ~ L) ==> { case _ ~ y => Write(y): Exp } || L lazy val L: Parser[List[Token], Exp] = - (T ~ T_OP("+") ~ Exp) ==> { case ((x, y), z) => Aop("+", x, z): Exp } || - (T ~ T_OP("-") ~ Exp) ==> { case ((x, y), z) => Aop("-", x, z): Exp } || T + (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, y), z) => Aop("*", x, z): Exp } || - (F ~ T_OP("/") ~ T) ==> { case ((x, y), z) => Aop("/", x, z): Exp } || - (F ~ T_OP("%") ~ T) ==> { case ((x, y), z) => Aop("%", x, z): Exp } || F + (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, y), z), w) => Call(x, z): Exp } || - (T_LPAREN ~ Exp ~ T_RPAREN) ==> { case ((x, y), z) => y: Exp } || + { 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, y), z) => Bop("==", x, z): BExp } || - (Exp ~ T_OP("!=") ~ Exp) ==> { case ((x, y), z) => Bop("!=", x, z): BExp } || - (Exp ~ T_OP("<") ~ Exp) ==> { case ((x, y), z) => Bop("<", x, z): BExp } || - (Exp ~ T_OP(">") ~ Exp) ==> { case ((x, y), z) => Bop("<", z, x): BExp } || - (Exp ~ T_OP("<=") ~ Exp) ==> { case ((x, y), z) => Bop("<=", x, z): BExp } || - (Exp ~ T_OP("=>") ~ Exp) ==> { case ((x, y), z) => Bop("<=", z, x): 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 } + { case _ ~ y ~ _ ~ w ~ _ ~ _ ~ r => Def(y, w, r): Decl } lazy val Prog: Parser[List[Token], List[Decl]] = - (Defn ~ T_SEMI ~ Prog) ==> { case ((x, y), z) => x :: z : List[Decl] } || + (Defn ~ T_SEMI ~ Prog) ==> { case x ~ _ ~ z => x :: z : List[Decl] } || (Exp ==> ((s) => List(Main(s)) : List[Decl]))