Use smart insertion and deletion in alterF

[sjakobi]

No description provided.

[sjakobi]

@treeowl does this look like a good idea?

If so, I can extend it to alter and strict alterF.

[treeowl]

Sounds plausible. Please be sure to do some benchmarking.

[treeowl]

You have a chance to benchmark any?

[sjakobi]

You have a chance to benchmark any?

Not yet. I had a look at the existing benchmarks for alterF and noticed that all of these are being rewritten to use insert and delete under the hood. What would be good functors to benchmark the basic alterF and alterFEager with?

[sjakobi]

What would be good functors to benchmark the basic alterF and alterFEager with?

Maybe I can simply use something like

data Pair a = Pair a a

instance Functor Pair where
  fmap f (Pair a b) = Pair (f a) (f b)

[treeowl]

Lots of things to play with. Can't be exhaustive.

…

On Sun, Feb 28, 2021, 10:05 AM Simon Jakobi ***@***.***> wrote: What would be good functors to benchmark the basic alterF and alterFEager with? Maybe I can simply use something like data Pair a = Pair a a instance Functor Pair where fmap f (Pair a b) = Pair (f a) (f b) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#289 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAOOF7KJ2HU6N6OE2GR5WVDTBJLSRANCNFSM4PE5QE6Q> .

[sjakobi]

FWIW, here's the Core diff for the current patch:

--- RHS size: {terms: 65, types: 88, coercions: 0, joins: 0/3}
+-- RHS size: {terms: 79, types: 99, coercions: 0, joins: 0/2}
 $walterF
   = \ @ f @ k @ v w w1 w2 w3 w4 ->
       case w3 of k1 { __DEFAULT ->
       case w4 of m { __DEFAULT ->
       case hash w1 k1 of { I# x# ->
-      let { $dEq = $p1Hashable w1 } in
       let { ipv = int2Word# x# } in
       let {
-        mv
-          = case $wlookupRecordCollision# $dEq ipv k1 m of {
-              (#_|#) ds1 -> Nothing;
-              (#|_#) ds1 -> case ds1 of { (# a, _i #) -> Just a }
+        lookupRes
+          = case $wlookupRecordCollision# ($p1Hashable w1) ipv k1 m of {
+              (#_|#) ds1 -> Absent;
+              (#|_#) ds1 -> case ds1 of { (# a, i #) -> Present a i }
             } } in
       fmap
         w
         (\ fres ->
            case fres of {
              Nothing ->
-               case mv of {
-                 Nothing -> m;
-                 Just x -> $wdelete' $dEq ipv k1 m
+               case lookupRes of {
+                 Absent -> m;
+                 Present ds dt -> $wdeleteKeyExists dt ipv k1 m
                };
-             Just v' -> $winsert' $dEq ipv k1 v' m
+             Just v' ->
+               case lookupRes of {
+                 Absent -> $winsertNewKey ipv k1 v' m;
+                 Present ds dt -> $winsertKeyExists dt ipv k1 v' m
+               }
            })
-        (w2 mv)
+        (w2
+           (case lookupRes of {
+              Absent -> Nothing;
+              Present x dt -> Just x
+            }))
       }
       }
       }