Give an event locals

LOCAL_LOAD and LOCAL_STORE name one of an event's 64 slots, what it holds
(a number, or an index of a list) and that list: slots start at 0 when an
event begins, are shared by its handlers, the walks in them and the folds
in those, and are never saved nor in the states' namespace. A handler uses
a slot for one thing, so its type is verified as a state's is; views have
no locals (IN_LOCALS: a handler's block, a walk in it, a fold in either;
stores only in a handler and its walks). A fold reading a local still runs
a leaf at a time (one value for every item) and a shaped fold takes one
only on its key's side. The signature table's where widens to 16 bits.

locals checks a handler that sums items into a local in a walk, counts in
a fold the items below it, keeps an index in a local and reads it back,
over 80 events against a model, and five refusals. server_rows' shop now
takes stock through an index local and counts in one.

1 files changed, 6 insertions, 3 deletions

diff --git a/tests/check.py b/tests/check.py
index 2020363..4387120 100644
--- a/tests/check.py
+++ b/tests/check.py
@@ -1059,12 +1059,15 @@ on restock {
   }
 }
 on order {
+  let taken = 0
   for l in order.lines {
-    stock[l.item].left = stock[l.item].left - l.qty
-    require stock[l.item].left >= 0
+    let s = stock[l.item]
+    s.left = s.left - l.qty
+    require s.left >= 0
     log.append(Entry { item: l.item, qty: l.qty, note: l.note })
+    taken = taken + 1
   }
-  orders = orders + order.lines.count
+  orders = orders + taken
 }
 on clean {
   for s in stock where s.left < clean.below {