table tab : {Id : int, Val : int, Foo : int} PRIMARY KEY Id
fun cache id =
res <- oneOrNoRows (SELECT A.Val FROM (tab AS A JOIN tab AS B ON A.Id = B.Id)
WHERE B.Id = {[id]});
return
cache
{case res of
None => ?
| Some row => {[row.A.Val]}}
(* fun cacheAlt id = *)
(* res <- oneOrNoRows (SELECT Q.Id *)
(* FROM (SELECT Tab.Id AS Id FROM tab WHERE Tab.Id = {[id]}) *)
(* AS Q); *)
(* return *)
(* cacheAlt *)
(* {case res of *)
(* None => ? *)
(* | Some row => {[row.Q.Id]}} *)
(* *)
(* fun sillyRecursive {Id = id : int, FooBar = fooBar} = *)
(* if fooBar <= 0 *)
(* then 0 *)
(* else 1 + sillyRecursive {Id = id, FooBar = fooBar - 1} *)
(* fun cacheR (r : {Id : int, FooBar : int}) = *)
(* res <- oneOrNoRows (SELECT tab.Val *)
(* FROM tab *)
(* WHERE tab.Id = {[r.Id]}); *)
(* return *)
(* cacheR {[r.FooBar]} *)
(* {case res of *)
(* None => ? *)
(* | Some row => {[row.Tab.Val]}} *)
(* *)
(* fun cache2 id v = *)
(* res <- oneOrNoRows (SELECT tab.Val *)
(* FROM tab *)
(* WHERE tab.Id = {[id]} AND tab.Val = {[v]}); *)
(* return *)
(* Reading {[id]}. *)
(* {case res of *)
(* None => Nope, that's not it. *)
(* | Some _ => Hooray! You guessed it!} *)
(* *)
(* fun cache2 id1 id2 = *)
(* res1 <- oneOrNoRows (SELECT tab.Val *)
(* FROM tab *)
(* WHERE tab.Id = {[id1]}); *)
(* res2 <- oneOrNoRows (SELECT tab.Val *)
(* FROM tab *)
(* WHERE tab.Id = {[id2]}); *)
(* return *)
(* Reading {[id1]} and {[id2]}. *)
(* {case (res1, res2) of *)
(* (Some _, Some _) => Both are there. *)
(* | _ => One of them is missing.} *)
(* *)
fun flush id =
dml (UPDATE tab
SET Val = Val * (Id + 2) / Val - 3
WHERE Id = {[id]} OR Id = {[id - 1]} OR Id = {[id + 1]});
return
Changed {[id]}!
(* fun flash id = *)
(* dml (UPDATE tab *)
(* SET Foo = Val *)
(* WHERE Id = {[id]} OR Id = {[id - 1]} OR Id = {[id + 1]}); *)
(* return *)
(* Maybe changed {[id]}? *)
(* *)
(* fun floosh id = *)
(* dml (UPDATE tab *)
(* SET Id = {[id + 1]} *)
(* WHERE Id = {[id]} OR Id = {[id - 1]} OR Id = {[id + 1]}); *)
(* return *)
(* Shifted {[id]}! *)
(* *)
(* val flush17 = *)
(* dml (UPDATE tab *)
(* SET Val = Val * (Id + 2) / Val - 3 *)
(* WHERE Id = 17); *)
(* return *)
(* Changed specifically 17! *)
(* *)
(* fun flush id = *)
(* res <- oneOrNoRows (SELECT tab.Val *)
(* FROM tab *)
(* WHERE tab.Id = {[id]}); *)
(* (case res of *)
(* None => dml (INSERT INTO tab (Id, Val) *)
(* VALUES ({[id]}, 0)) *)
(* | Some row => dml (UPDATE tab *)
(* SET Val = {[row.Tab.Val + 1]} *)
(* WHERE Id = {[id]} OR Id = {[id + 1]})); *)
(* return *)
(* {case res of *)
(* None => Initialized {[id]}! *)
(* | Some row => Incremented {[id]}!} *)
(* *)