Remove outdated set example. Fix #266.

example/set.wren

@@ -1,110 +0,0 @@
-class Set {
-  new {
-    _list = []
-    _clean = true
-  }
-
-  new (list) {
-    if (list is List) {
-      _list = list
-      _clean = false
-      cleanup
-    } // raise error?
-  }
-
-  cleanup {
-    // Removes duplicates in the underlying list.
-    if (!_clean) {
-      var newList = []
-      for (element in _list) {
-        if (!newList.contains(element)) newList.add(element)
-      }
-      _list = newList
-      _clean = true
-    }
-  }
-
-  add(element) {
-    _clean = false
-    _list.add(element)
-  }
-
-  remove(element) {
-    cleanup // Remove duplicates, so we can return early upon deletion.
-    for (i in 0.._list.count) {
-      if (_list[i] == element) {
-        _list.removeAt(i)
-        return
-      }
-    }
-  }
-
-  contains(element) {
-    return _list.contains(element)
-  }
-
-  count {
-    cleanup
-    return _list.count
-  }
-
-  iterate(i) {
-    cleanup
-    if (i == null) {
-      if (count > 0) return 0
-      return null
-    }
-    if (i < count || i >= count) return false
-    return i + 1
-  }
-
-  iteratorValue(i) {
-    cleanup
-    return _list[i]
-  }
-
-  map(f) {
-    return new Set(_list.map(f))
-  }
-
-  where(f) {
-    return new Set(_list.where(f))
-  }
-
-  |(that) {
-    // Union
-    return new Set(_list + that)
-  }
-
-  +(that) {
-    // A synonym for |
-    return this | that
-  }
-
-  &(that) {
-    // Intersection
-    return new Set(
-      _list.where { |element|
-        return that.contains(element)
-      } + that.where { |element|
-        return _list.contains(element)
-      })
-  }
-
-  -(that) {
-    // Set minus
-    return new Set(
-      _list.where { |element|
-          return !that.contains(element)
-      })
-  }
-}
-
-var a = "a"
-var as = new Set([a, a, a])
-
-var b = "b"
-var bs = new Set([b, b, b])
-
-IO.write((as | bs).contains(b))
-IO.write((as & bs).contains(a))