src/Pure/Thy/thy_load.scala

 
 
 object Thy_Load
 {
   def thy_path(path: Path): Path = path.ext("thy")
+
+  def is_ok(str: String): Boolean =
+    try { thy_path(Path.explode(str)); true }
+    catch { case ERROR(_) => false }
 }
 
 
 class Thy_Load(preloaded: Set[String] = Set.empty)
 {