fed-sx-m2: Step 11b — Announce + Endorse projection folds + 19 tests

Two new projection modules for the rich verbs landed in Step 11a:

  next/kernel/announce_state.erl
    Per-target-Cid announcer set.
    State: [{TargetCid, [AnnouncerActorId, ...]}, ...]
    Set semantics — duplicate Announce by the same actor on the
    same target is a no-op.

    Public API:
      new/0, fold/2, fold_fn/0
      announcers_for/2, announce_count/2, announced_cids/1
      has_announced/3

  next/kernel/endorsement_state.erl
    Per-target-Cid + per-kind + per-actor endorsement counter.
    State: [{TargetCid, [{Kind, [{ActorId, Count}, ...]}, ...]}, ...]
    Additive semantics — re-endorse by the same actor under the
    same kind bumps the counter. Undo{Endorse} retraction defers
    to a follow-up.

    Public API:
      new/0, fold/2, fold_fn/0
      counters_for/2, total_for/2, kinds_for/2
      endorsers_for/3, has_endorsed/4

Both fold_fn/0 returns a 2-arity Erlang fun for
projection:start_link/3 (same plug shape as actor_state /
follower_graph / delivery_state). Non-matching activity types
pass through unchanged.

Read-side accessors cover both enumeration (announcers_for,
endorsers_for) and predicates (has_announced, has_endorsed) so
the feed/timeline projection layer doesn't have to re-implement
that logic on every consumer.

19/19 in next/tests/rich_verbs.sh:

  announce_state:
    - new/0 -> []
    - Announce -> announcer added
    - Two announces same target -> both in set
    - Duplicate announce by same actor -> no-op
    - announce_count + announced_cids
    - has_announced predicate
    - fold_fn/0 is fun/2
    - Non-Announce activity passes through

  endorsement_state:
    - new/0 -> []
    - Endorse -> counter 1
    - Two likes by different actors -> total 2
    - like + share -> two kinds tracked
    - endorsers_for(Cid, Kind)
    - has_endorsed predicate
    - fold_fn/0 is fun/2
    - Non-Endorse activity passes through
    - Same actor endorsing twice -> total = 2 (additive)

Conformance preserved at 761/761.

next/kernel/announce_state.erl

@@ -0,0 +1,79 @@
+-module(announce_state).
+-export([new/0, fold/2, fold_fn/0,
+         announcers_for/2, announce_count/2, announced_cids/1,
+         has_announced/3]).
+
+%% Announce-fanout projection. Folds Announce activities into a
+%% per-target-Cid set of announcer ActorIds so projections can
+%% answer "who re-broadcast this activity" / "how many announces
+%% does this Note have" / "what activities has X announced".
+%%
+%% Announce envelope shape (per next/genesis/activity-types/announce.sx):
+%%   [{type, announce},
+%%    {actor, AnnouncerActorId},
+%%    {object, TargetCidBinary},
+%%    ...]
+%%
+%% State shape:
+%%   [{TargetCid, [Announcer1, Announcer2, ...]}, ...]
+%%
+%% Set semantics — the same actor announcing the same target twice
+%% is a no-op (already in the list). Undo{Announce} retraction
+%% defers to a follow-up.
+
+new() -> [].
+
+fold_fn() ->
+    fun (Activity, State) -> fold(Activity, State) end.
+
+fold(Activity, State) ->
+    case envelope:get_field(type, Activity) of
+        {ok, announce} -> fold_announce(Activity, State);
+        _              -> State
+    end.
+
+fold_announce(Activity, State) ->
+    case {envelope:get_field(actor, Activity),
+          envelope:get_field(object, Activity)} of
+        {{ok, Actor}, {ok, Cid}} -> add_announcer(Cid, Actor, State);
+        _                        -> State
+    end.
+
+add_announcer(Cid, Actor, State) ->
+    Current = case find_keyed(Cid, State) of
+        {ok, Set} -> Set;
+        _         -> []
+    end,
+    case contains(Actor, Current) of
+        true  -> State;
+        false -> set_keyed(Cid, Current ++ [Actor], State)
+    end.
+
+%% ── Read-side accessors ───────────────────────────────────────
+
+announcers_for(Cid, State) ->
+    case find_keyed(Cid, State) of
+        {ok, Set} -> Set;
+        _         -> []
+    end.
+
+announce_count(Cid, State) -> length(announcers_for(Cid, State)).
+
+announced_cids(State) -> [C || {C, _} <- State].
+
+has_announced(Actor, Cid, State) ->
+    contains(Actor, announcers_for(Cid, State)).
+
+%% ── Internal ──────────────────────────────────────────────────
+
+contains(_, []) -> false;
+contains(X, [X | _]) -> true;
+contains(X, [_ | Rest]) -> contains(X, Rest).
+
+find_keyed(_, []) -> {error, not_found};
+find_keyed(K, [{K, V} | _]) -> {ok, V};
+find_keyed(K, [_ | Rest]) -> find_keyed(K, Rest).
+
+set_keyed(K, V, []) -> [{K, V}];
+set_keyed(K, V, [{K, _} | Rest]) -> [{K, V} | Rest];
+set_keyed(K, V, [P | Rest]) -> [P | set_keyed(K, V, Rest)].

next/kernel/endorsement_state.erl

@@ -0,0 +1,118 @@
+-module(endorsement_state).
+-export([new/0, fold/2, fold_fn/0,
+         counters_for/2, total_for/2, kinds_for/2,
+         endorsers_for/3, has_endorsed/4]).
+
+%% Endorsement counter projection. Folds Endorse activities into a
+%% per-target-Cid + per-kind counter so projections can serve
+%% "how many likes does this Note have" / "list everyone who shared
+%% this Announce" queries.
+%%
+%% Endorse envelope shape (per next/genesis/activity-types/endorse.sx):
+%%   [{type, endorse},
+%%    {actor, ActorId},
+%%    {object, TargetCidBinary},
+%%    {kind, KindAtomOrBinary},
+%%    ...]
+%%
+%% State shape:
+%%   [{TargetCid, [{Kind, [{ActorId, Count}, ...]}, ...]}, ...]
+%%
+%% Each ActorId can endorse the same target multiple times under
+%% the same kind (e.g. like → unlike → like → ...); the counter
+%% tracks how many *net* endorsement events fired. Step 11b ships
+%% the additive counter only; the unlike / un-endorse semantics
+%% (Undo{Endorse}) and reaction-toggling defer to a follow-up.
+
+new() -> [].
+
+fold_fn() ->
+    fun (Activity, State) -> fold(Activity, State) end.
+
+fold(Activity, State) ->
+    case envelope:get_field(type, Activity) of
+        {ok, endorse} -> fold_endorse(Activity, State);
+        _             -> State
+    end.
+
+fold_endorse(Activity, State) ->
+    case {envelope:get_field(actor, Activity),
+          envelope:get_field(object, Activity),
+          envelope:get_field(kind, Activity)} of
+        {{ok, Actor}, {ok, Cid}, {ok, Kind}} ->
+            bump(Cid, Kind, Actor, State);
+        _ ->
+            State
+    end.
+
+bump(Cid, Kind, Actor, State) ->
+    KindMap = case find_keyed(Cid, State) of
+        {ok, KM} -> KM;
+        _        -> []
+    end,
+    ActorMap = case find_keyed(Kind, KindMap) of
+        {ok, AM} -> AM;
+        _        -> []
+    end,
+    Current = case find_keyed(Actor, ActorMap) of
+        {ok, N} -> N;
+        _       -> 0
+    end,
+    ActorMap1 = set_keyed(Actor, Current + 1, ActorMap),
+    KindMap1  = set_keyed(Kind, ActorMap1, KindMap),
+    set_keyed(Cid, KindMap1, State).
+
+%% ── Read-side accessors ───────────────────────────────────────
+
+%% counters_for(Cid, State) -> [{Kind, TotalCount}, ...]
+%% Sum per-kind across all endorsers.
+
+counters_for(Cid, State) ->
+    case find_keyed(Cid, State) of
+        {ok, KindMap} ->
+            [{K, sum_counts(AM)} || {K, AM} <- KindMap];
+        _ -> []
+    end.
+
+total_for(Cid, State) ->
+    lists:foldl(fun ({_, N}, Acc) -> N + Acc end, 0, counters_for(Cid, State)).
+
+kinds_for(Cid, State) ->
+    [K || {K, _} <- counters_for(Cid, State)].
+
+endorsers_for(Cid, Kind, State) ->
+    case find_keyed(Cid, State) of
+        {ok, KindMap} ->
+            case find_keyed(Kind, KindMap) of
+                {ok, AM} -> [A || {A, _} <- AM];
+                _        -> []
+            end;
+        _ -> []
+    end.
+
+has_endorsed(Actor, Cid, Kind, State) ->
+    case find_keyed(Cid, State) of
+        {ok, KindMap} ->
+            case find_keyed(Kind, KindMap) of
+                {ok, AM} ->
+                    case find_keyed(Actor, AM) of
+                        {ok, N} -> N > 0;
+                        _       -> false
+                    end;
+                _ -> false
+            end;
+        _ -> false
+    end.
+
+%% ── Internal ──────────────────────────────────────────────────
+
+sum_counts([]) -> 0;
+sum_counts([{_, N} | Rest]) -> N + sum_counts(Rest).
+
+find_keyed(_, []) -> {error, not_found};
+find_keyed(K, [{K, V} | _]) -> {ok, V};
+find_keyed(K, [_ | Rest]) -> find_keyed(K, Rest).
+
+set_keyed(K, V, []) -> [{K, V}];
+set_keyed(K, V, [{K, _} | Rest]) -> [{K, V} | Rest];
+set_keyed(K, V, [P | Rest]) -> [P | set_keyed(K, V, Rest)].

next/tests/rich_verbs.sh

@@ -0,0 +1,163 @@
+#!/usr/bin/env bash
+# next/tests/rich_verbs.sh — m2 Step 11b test.
+#
+# Projection folds for Announce + Endorse activity-types.
+# announce_state tracks per-cid announcer sets;
+# endorsement_state tracks per-cid + per-kind + per-actor counters.
+
+set -uo pipefail
+cd "$(git rev-parse --show-toplevel)"
+
+SX_SERVER="${SX_SERVER:-hosts/ocaml/_build/default/bin/sx_server.exe}"
+if [ ! -x "$SX_SERVER" ]; then
+  SX_SERVER="/root/rose-ash/hosts/ocaml/_build/default/bin/sx_server.exe"
+fi
+if [ ! -x "$SX_SERVER" ]; then
+  echo "ERROR: sx_server.exe not found." >&2
+  exit 1
+fi
+
+VERBOSE="${1:-}"
+PASS=0; FAIL=0; ERRORS=""
+TMPFILE=$(mktemp); trap "rm -f $TMPFILE" EXIT
+
+# Cid1/Cid2 are the targets being announced/endorsed.
+SETUP='Cid1 = <<99,49>>, Cid2 = <<99,50>>, Ann_BC1 = [{type, announce}, {actor, bob}, {object, Cid1}], Ann_CC1 = [{type, announce}, {actor, carol}, {object, Cid1}], Ann_BC2 = [{type, announce}, {actor, bob}, {object, Cid2}], End_BLikeC1 = [{type, endorse}, {actor, bob}, {object, Cid1}, {kind, like}], End_CLikeC1 = [{type, endorse}, {actor, carol}, {object, Cid1}, {kind, like}], End_BShareC1 = [{type, endorse}, {actor, bob}, {object, Cid1}, {kind, share}],'
+
+cat > "$TMPFILE" <<EPOCHS
+(epoch 1)
+(load "lib/erlang/tokenizer.sx")
+(load "lib/erlang/parser.sx")
+(load "lib/erlang/parser-core.sx")
+(load "lib/erlang/parser-expr.sx")
+(load "lib/erlang/parser-module.sx")
+(load "lib/erlang/transpile.sx")
+(load "lib/erlang/runtime.sx")
+(load "lib/erlang/vm/dispatcher.sx")
+(epoch 2)
+(eval "(get (erlang-load-module (file-read \"next/kernel/envelope.erl\")) :name)")
+(epoch 3)
+(eval "(get (erlang-load-module (file-read \"next/kernel/announce_state.erl\")) :name)")
+(epoch 4)
+(eval "(get (erlang-load-module (file-read \"next/kernel/endorsement_state.erl\")) :name)")
+
+;; announce_state new/0
+(epoch 10)
+(eval "(get (erlang-eval-ast \"announce_state:new() =:= []\") :name)")
+
+;; Announce -> announcer added
+(epoch 11)
+(eval "(get (erlang-eval-ast \"${SETUP} S = announce_state:fold(Ann_BC1, announce_state:new()), announce_state:announcers_for(Cid1, S) =:= [bob]\") :name)")
+
+;; Two announces same target -> both announcers
+(epoch 12)
+(eval "(get (erlang-eval-ast \"${SETUP} S = announce_state:fold(Ann_CC1, announce_state:fold(Ann_BC1, announce_state:new())), announce_state:announcers_for(Cid1, S) =:= [bob, carol]\") :name)")
+
+;; Duplicate announce by same actor -> no double-add
+(epoch 13)
+(eval "(get (erlang-eval-ast \"${SETUP} S = announce_state:fold(Ann_BC1, announce_state:fold(Ann_BC1, announce_state:new())), announce_state:announcers_for(Cid1, S) =:= [bob]\") :name)")
+
+;; announce_count + announced_cids
+(epoch 14)
+(eval "(get (erlang-eval-ast \"${SETUP} S = announce_state:fold(Ann_BC2, announce_state:fold(Ann_CC1, announce_state:fold(Ann_BC1, announce_state:new()))), {announce_state:announce_count(Cid1, S), announce_state:announce_count(Cid2, S), announce_state:announced_cids(S)} =:= {2, 1, [Cid1, Cid2]}\") :name)")
+
+;; has_announced predicate
+(epoch 15)
+(eval "(get (erlang-eval-ast \"${SETUP} S = announce_state:fold(Ann_BC1, announce_state:new()), {announce_state:has_announced(bob, Cid1, S), announce_state:has_announced(carol, Cid1, S)} =:= {true, false}\") :name)")
+
+;; announce_state fold_fn/0 is fun/2
+(epoch 16)
+(eval "(get (erlang-eval-ast \"is_function(announce_state:fold_fn(), 2)\") :name)")
+
+;; Non-Announce activity passes through
+(epoch 17)
+(eval "(get (erlang-eval-ast \"Note = [{type, note}, {actor, alice}, {object, [{content, hi}]}], announce_state:fold(Note, announce_state:new()) =:= []\") :name)")
+
+;; ── endorsement_state ─────────────────────────────────────
+
+;; new/0
+(epoch 20)
+(eval "(get (erlang-eval-ast \"endorsement_state:new() =:= []\") :name)")
+
+;; Endorse -> counter goes to 1
+(epoch 21)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_BLikeC1, endorsement_state:new()), endorsement_state:counters_for(Cid1, S) =:= [{like, 1}]\") :name)")
+
+;; Two like-endorses by different actors -> total = 2
+(epoch 22)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_CLikeC1, endorsement_state:fold(End_BLikeC1, endorsement_state:new())), endorsement_state:total_for(Cid1, S) =:= 2\") :name)")
+
+;; like + share -> two kinds
+(epoch 23)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_BShareC1, endorsement_state:fold(End_BLikeC1, endorsement_state:new())), endorsement_state:kinds_for(Cid1, S) =:= [like, share]\") :name)")
+
+;; endorsers_for(Cid, like)
+(epoch 24)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_CLikeC1, endorsement_state:fold(End_BLikeC1, endorsement_state:new())), endorsement_state:endorsers_for(Cid1, like, S) =:= [bob, carol]\") :name)")
+
+;; has_endorsed predicate
+(epoch 25)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_BLikeC1, endorsement_state:new()), {endorsement_state:has_endorsed(bob, Cid1, like, S), endorsement_state:has_endorsed(carol, Cid1, like, S), endorsement_state:has_endorsed(bob, Cid1, share, S)} =:= {true, false, false}\") :name)")
+
+;; endorsement_state fold_fn/0 is fun/2
+(epoch 26)
+(eval "(get (erlang-eval-ast \"is_function(endorsement_state:fold_fn(), 2)\") :name)")
+
+;; Non-Endorse activity passes through
+(epoch 27)
+(eval "(get (erlang-eval-ast \"Note = [{type, note}, {actor, alice}, {object, [{content, hi}]}], endorsement_state:fold(Note, endorsement_state:new()) =:= []\") :name)")
+
+;; Same actor endorsing twice bumps the counter (additive semantics)
+(epoch 28)
+(eval "(get (erlang-eval-ast \"${SETUP} S = endorsement_state:fold(End_BLikeC1, endorsement_state:fold(End_BLikeC1, endorsement_state:new())), endorsement_state:total_for(Cid1, S) =:= 2\") :name)")
+EPOCHS
+
+OUTPUT=$(timeout 280 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
+
+check() {
+  local epoch="$1" desc="$2" expected="$3"
+  local actual
+  actual=$(echo "$OUTPUT" | awk -v e="$epoch" '
+    $0 ~ "^\\(ok-len " e " " { getline; print; exit }
+    $0 ~ "^\\(ok " e " "     { print; exit }
+    $0 ~ "^\\(error " e " "  { print; exit }
+  ')
+  [ -z "$actual" ] && actual="<no output for epoch $epoch>"
+  if echo "$actual" | grep -qF -- "$expected"; then
+    PASS=$((PASS+1))
+    [ "$VERBOSE" = "-v" ] && echo "  ok $desc"
+  else
+    FAIL=$((FAIL+1))
+    ERRORS+="  FAIL [$desc] (epoch $epoch) expected: $expected | actual: $actual
+"
+  fi
+}
+
+check  3  "announce_state module loaded"     "announce_state"
+check  4  "endorsement_state module loaded"  "endorsement_state"
+check 10  "announce_state:new -> []"         "true"
+check 11  "Announce -> announcer"            "true"
+check 12  "Two announces same target"        "true"
+check 13  "Duplicate announce no-op"         "true"
+check 14  "count / announced_cids"           "true"
+check 15  "has_announced predicate"          "true"
+check 16  "announce fold_fn/0 fun/2"         "true"
+check 17  "Non-Announce passes through"      "true"
+check 20  "endorsement_state:new -> []"      "true"
+check 21  "Endorse -> counter 1"             "true"
+check 22  "Two likes -> total 2"             "true"
+check 23  "like + share -> two kinds"        "true"
+check 24  "endorsers_for(Cid, like)"         "true"
+check 25  "has_endorsed predicate"           "true"
+check 26  "endorse fold_fn/0 fun/2"          "true"
+check 27  "Non-Endorse passes through"       "true"
+check 28  "Same actor endorse twice -> 2"    "true"
+
+TOTAL=$((PASS+FAIL))
+if [ $FAIL -eq 0 ]; then
+  echo "ok $PASS/$TOTAL next/tests/rich_verbs.sh passed"
+else
+  echo "FAIL $PASS/$TOTAL passed, $FAIL failed:"
+  echo "$ERRORS"
+fi
+[ $FAIL -eq 0 ]

plans/fed-sx-milestone-2.md

@@ -726,6 +726,22 @@ re-broadcast another actor's content to their own followers.
 
 **Deliverables:**
 
+- [x] **11b** — Projection folds for the new verbs.
+  - `next/kernel/announce_state.erl`: tracks per-Cid announcer
+    set. Public API `new/0`, `fold/2`, `fold_fn/0`,
+    `announcers_for/2`, `announce_count/2`,
+    `announced_cids/1`, `has_announced/3`. Set semantics
+    (duplicate Announce by same actor is a no-op).
+  - `next/kernel/endorsement_state.erl`: tracks per-Cid +
+    per-kind + per-actor endorsement counters. Public API
+    `new/0`, `fold/2`, `fold_fn/0`, `counters_for/2`,
+    `total_for/2`, `kinds_for/2`, `endorsers_for/3`,
+    `has_endorsed/4`. Additive semantics (re-endorse by same
+    actor under same kind bumps the counter; Undo{Endorse}
+    semantics defer to a follow-up).
+  Both `fold_fn/0`s plug into `projection:start_link/3`. 19/19
+  in `rich_verbs.sh` covering happy paths + predicates + non-
+  matching-activity pass-through.
 - [x] **11a** — Announce + Endorse genesis activity-types
   (Note already exists as an object-type from M1 — Create{Note}
   is the publish path). Two new `DefineActivity` SX files in
@@ -994,6 +1010,20 @@ proceed.
 
 Newest first.
 
+- **2026-06-07** — Step 11b: projection folds for the new verbs.
+  Two new modules in `next/kernel/`:
+  `announce_state.erl` (per-Cid announcer-set fold, set
+  semantics) and `endorsement_state.erl` (per-Cid + per-kind
+  + per-actor counter, additive semantics). Both follow the
+  same plug shape as `actor_state` / `follower_graph` /
+  `delivery_state`: `fold_fn/0` returns a 2-arity Erlang fun
+  for `projection:start_link/3`. Non-matching activities pass
+  through unchanged. Read-side accessors cover both
+  enumeration (announcers_for / endorsers_for) and predicates
+  (has_announced / has_endorsed) so the feed/timeline layer
+  doesn't have to re-implement that logic. 19/19 in
+  `rich_verbs.sh`. Conformance preserved at 761/761.
+
 - **2026-06-07** — Step 11a: Announce + Endorse genesis
   activity-types. Two new DefineActivity SX files in
   `next/genesis/activity-types/`: announce.sx (`:object` is a