--- a/src/Pure/term_xml.scala Thu Oct 10 15:52:30 2019 +0200
+++ b/src/Pure/term_xml.scala Thu Oct 10 16:51:47 2019 +0200
@@ -15,19 +15,26 @@
{
import XML.Encode._
+ val indexname: P[Indexname] =
+ { case Indexname(a, 0) => List(a)
+ case Indexname(a, b) => List(a, int_atom(b)) }
+
val sort: T[Sort] = list(string)
- def typ: T[Typ] =
+ def typ_raw: T[Typ] =
variant[Typ](List(
- { case Type(a, b) => (List(a), list(typ)(b)) },
+ { case Type(a, b) => (List(a), list(typ_raw)(b)) },
{ case TFree(a, b) => (List(a), sort(b)) },
- { case TVar(Indexname(a, b), c) => (List(a, int_atom(b)), sort(c)) }))
+ { case TVar(a, b) => (indexname(a), sort(b)) }))
+
+ val typ: T[Typ] =
+ { case t => option(typ_raw)(if (t == dummyT) None else Some(t)) }
def term: T[Term] =
variant[Term](List(
{ case Const(a, b) => (List(a), list(typ)(b)) },
{ case Free(a, b) => (List(a), typ(b)) },
- { case Var(Indexname(a, b), c) => (List(a, int_atom(b)), typ(c)) },
+ { case Var(a, b) => (indexname(a), typ(b)) },
{ case Bound(a) => (List(int_atom(a)), Nil) },
{ case Abs(a, b, c) => (List(a), pair(typ, term)(b, c)) },
{ case App(a, b) => (Nil, pair(term, term)(a, b)) }))
@@ -37,19 +44,25 @@
{
import XML.Decode._
+ val indexname: P[Indexname] =
+ { case List(a) => Indexname(a, 0)
+ case List(a, b) => Indexname(a, int_atom(b)) }
+
val sort: T[Sort] = list(string)
- def typ: T[Typ] =
+ def typ_raw: T[Typ] =
variant[Typ](List(
- { case (List(a), b) => Type(a, list(typ)(b)) },
+ { case (List(a), b) => Type(a, list(typ_raw)(b)) },
{ case (List(a), b) => TFree(a, sort(b)) },
- { case (List(a, b), c) => TVar(Indexname(a, int_atom(b)), sort(c)) }))
+ { case (a, b) => TVar(indexname(a), sort(b)) }))
+
+ def typ(body: XML.Body): Typ = option(typ_raw)(body).getOrElse(dummyT)
def term: T[Term] =
variant[Term](List(
{ case (List(a), b) => Const(a, list(typ)(b)) },
{ case (List(a), b) => Free(a, typ(b)) },
- { case (List(a, b), c) => Var(Indexname(a, int_atom(b)), typ(c)) },
+ { case (a, b) => Var(indexname(a), typ(b)) },
{ case (List(a), Nil) => Bound(int_atom(a)) },
{ case (List(a), b) => val (c, d) = pair(typ, term)(b); Abs(a, c, d) },
{ case (Nil, a) => val (b, c) = pair(term, term)(a); App(b, c) }))