--- a/src/Pure/Thy/thy_info.scala Tue Aug 21 12:15:25 2012 +0200
+++ b/src/Pure/Thy/thy_info.scala Tue Aug 21 13:29:34 2012 +0200
@@ -25,7 +25,13 @@
/* dependencies */
type Dep = (Document.Node.Name, Document.Node.Header)
- private type Required = (List[Dep], Set[Document.Node.Name])
+ private sealed case class Required(
+ deps: List[Dep] = Nil,
+ seen: Set[Document.Node.Name] = Set.empty)
+ {
+ def :: (dep: Dep): Required = copy(deps = dep :: deps)
+ def + (name: Document.Node.Name): Required = copy(seen = seen + name)
+ }
private def require_thys(initiators: List[Document.Node.Name],
required: Required, names: List[Document.Node.Name]): Required =
@@ -34,9 +40,8 @@
private def require_thy(initiators: List[Document.Node.Name],
required: Required, name: Document.Node.Name): Required =
{
- val (deps, seen) = required
- if (seen(name)) required
- else if (thy_load.loaded_theories(name.theory)) (deps, seen + name)
+ if (required.seen(name)) required
+ else if (thy_load.loaded_theories(name.theory)) required + name
else {
try {
if (initiators.contains(name)) error(cycle_msg(initiators))
@@ -47,17 +52,15 @@
cat_error(msg, "The error(s) above occurred while examining theory " +
quote(name.theory) + required_by(initiators))
}
- val (deps1, seen1) =
- require_thys(name :: initiators, (deps, seen + name), header.imports)
- ((name, header) :: deps1, seen1)
+ (name, header) :: require_thys(name :: initiators, required + name, header.imports)
}
catch {
case e: Throwable =>
- ((name, Document.Node.bad_header(Exn.message(e))) :: deps, seen + name)
+ (name, Document.Node.bad_header(Exn.message(e))) :: (required + name)
}
}
}
def dependencies(names: List[Document.Node.Name]): List[Dep] =
- require_thys(Nil, (Nil, Set.empty), names)._1.reverse
+ require_thys(Nil, Required(), names).deps.reverse
}