Side A implements a substantive algorithmic improvement (spanning-tree bridge preference and rank-adjacent zipping) with well-reasoned sub-priorities and new targeted tests validating the behavior. Side B is a smaller cleanup/consistency fix removing dead-code duplication (toolbar + action), which is useful but far more limited in scope and lasting design impact.
constitution · epochs · watch · epoch 3
comparison
c_2722a3195825 (tommy-mor) vs c_f515f8a12d7a (tommy-mor)
download prompt · raw event · cmp_c8500313b93bc4
council reasoning
A redesigns core pair-selection (established-component merge before isolate attach, then rank-adjacent zip refinement) with supporting layout/sort keys and targeted tests—lasting ranking behavior. B only removes a redundant ExpandNewThreadForm path and SSRs the home compose slot for consistency, a useful but smaller cleanup.
Side A materially improves the pair-selection algorithm by introducing structured bridge and within-component priorities, preferring attachment to established voted components and then rank-adjacent refinement once the pool is connected. It also adds multiple targeted tests covering the new selection behavior. Side B mainly simplifies the HTML flow by server-rendering the new-thread slot on the home page and removing the now-redundant UI action and tests, which is a useful cleanup but has a narrower long-term impact.
sides
A — c_2722a3195825 (tommy-mor)
message
[5db58b98] Improve vote pair selection for spanning trees and rank refinement. Prefer attaching unranked items to established components before comparing isolates, then zip down adjacent rank-centrality pairs once the pool is fully connected, skipping pairs that already have votes. Co-authored-by: Cursor <cursoragent@cursor.com>
diff preview
diff --git a/server/src/pair.rs b/server/src/pair.rs
index 54b5d2417e9dba04ed8df422156e274c2b2f76b2..c14de4b0502c8b5a17cddf3746077739d56e03e0 100644
--- a/server/src/pair.rs
+++ b/server/src/pair.rs
@@ -3,13 +3,21 @@
//! Pair selection prefers **bridge** votes — comparisons between items in
//! different connected components of the voted-pairs graph — so the pool
//! merges into one ranking group before refining within it.
+//!
+//! Among unvoted bridges, prefer merging established voted components, then
+//! attaching a never-voted child to an established component, and only then
+//! comparing two never-voted children (so the voted graph grows as one tree).
+//!
+//! Once every pool child sits in one voted component, refinement **zips** down
+//! the rank-centrality order: prefer 1 vs 2, then 2 vs 3, and so on, skipping
+//! pairs that already have a vote.
use rand::seq::SliceRandom;
use std::collections::{HashMap, HashSet};
use crate::{
path_types::ItemId,
- ranking::connected_components_from_voted_pairs,
+ ranking::{connected_components_from_voted_pairs, ranked_items},
reducer::{GlobalTree, GroupState},
};
@@ -28,36 +36,77 @@ fn pair_is_voted(group: &GroupState, a: &ItemId, b: &ItemId) -> bool {
group.voted_pairs.contains(&(i, j))
}
-/// Component id per pool item: voted-pairs graph components plus one id per
-/// never-voted child.
-fn component_ids(group: &GroupState, pool: &[ItemId]) -> HashMap<ItemId, usize> {
+/// Voted-pairs layout for pool items: component id per item plus which ids are
+/// multi-node voted components (ranked groups in the UI).
+struct ComponentLayout {
+ ids: HashMap<ItemId, usize>,
+ established: HashSet<usize>,
+}
+
+fn component_layout(group: &GroupState, pool: &[ItemId]) -> ComponentLayout {
let n = group.idx_to_item.len();
let (comps, isolates) =
connected_components_from_voted_pairs(n, group.voted_pairs.iter().copied());
- let mut out: HashMap<ItemId, usize> = HashMap::new();
+ let mut established = HashSet::new();
+ let mut ids: HashMap<ItemId, usize> = HashMap::new();
for (comp_idx, comp) in comps.iter().enumerate() {
+ if comp.len() >= 2 {
+ established.insert(comp_idx);
+ }
for &idx in comp {
if idx < n {
- out.insert(group.idx_to_item[idx].clone(), comp_idx);
+ ids.insert(group.idx_to_item[idx].clone(), comp_idx);
}
}
}
let mut next = comps.len();
for &idx in &isolates {
if idx < n {
- out.insert(group.idx_to_item[idx].clone(), next);
+ ids.insert(group.idx_to_item[idx].clone(), next);
next += 1;
}
}
for item in pool {
- out.entry(item.clone()).or_insert_with(|| {
+ ids.entry(item.clone()).or_insert_with(|| {
let id = next;
next += 1;
id
});
}
- out
+ ComponentLayout { ids, established }
+}
+
+/// Every pool child shares one multi-node voted component (spanning tree phase done).
+fn pool_fully_connected(layout: &ComponentLayout, pool: &[ItemId]) -> bool {
+ if pool.len() < 2 {
+ return false;
+ }
+ let mut comp_id = None;
+ for item in pool {
+ let Some(id) = layout.ids.get(item) else {
+ return false;
+ };
+ if !layout.established.contains(id) {
+ return false;
+ }
+ match comp_id {
+ None => comp_id = Some(*id),
+ Some(expected) if expected == *id => {}
+ _ => return false,
+ }
+ }
+ comp_id.is_some()
+}
+
+/// Pool children that appear in `group`, sorted best rank first.
+fn ranked_pool_order(group: &GroupState, pool: &[ItemId]) -> Vec<ItemId> {
+ let pool_set: HashSet<_> = pool.iter().collect();
+ ranked_items(group)
+ .into_iter()
+ .map(|r| r.item)
+ .filter(|id| pool_set.contains(id))
+ .collect()
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
@@ -72,19 +121,108 @@ enum PairPriority {
WithinVoted = 3,
}
-fn pair_priority(
+/// Tie-break among unvoted bridge pairs.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+enum BridgeSubPriority {
+ /// Both endpoints lie in established (multi-node) voted components.
+ MergeEstablished = 0,
+ /// One established component member and one never-voted child.
+ AttachIsolate = 1,
+ /// Two never-voted children (separate singleton components).
+ IsolatePair = 2,
+}
+
+/// Tie-break among within-component pairs once the pool is one connected group.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+struct WithinSubPriority {
+ /// 1 = adjacent ranks (i vs i+1); larger = farther apart in the order.
+ rank_gap: usize,
+ /// min rank index of the two — zip from the top (1 vs 2 before 2 vs 3).
+ zip_index: usize,
+}
+
+const WITHIN_SUB_WORST: WithinSubPriority = WithinSubPriority {
+ rank_gap: usize::MAX,
+ zip_index: usize::MAX,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+struct PairSortKey {
+ priority: PairPriority,
+ bridge_sub: BridgeSubPriority,
+ within_sub: WithinSubPriority,
+}
+
+fn item_in_established(layout: &ComponentLayout, item: &ItemId) -> bool {
+ layout
+ .ids
+ .get(item)
+ .is_some_and(|id| layout.established.contains(id))
+}
+
+fn bridge_sub_priority(layout: &ComponentLayout, a: &ItemId, b: &ItemId) -> BridgeSubPriority {
+ let a_est = item_in_established(layout, a);
+ let b_est = item_in_established(layout, b);
+ match (a_est, b_est) {
+ (true, true) => BridgeSubPriority::MergeEstablished,
+ (true, false) | (false, true) => BridgeSubPriority::AttachIsolate,
+ (false, false) => BridgeSubPriority::IsolatePair,
+ }
+}
+
+fn within_sub_priority(
+ group: &GroupState,
+ pool: &[ItemId],
+ layout: &ComponentLayout,
+ a: &ItemId,
+ b: &ItemId,
+) -> WithinSubPriority {
+ if !pool_fully_connected(layout, pool) {
+ return WITHIN_SUB_WORST;
+ }
+ let order = ranked_pool_order(group, pool);
+ let (Some(i), Some(j)) = (order.iter().position(|x| x == a), order.iter().position(|x| x == b))
+ else {
+ return WITHIN_SUB_WORST;
+ };
+ WithinSubPriority {
+ rank_gap: i.abs_diff(j),
+ zip_index: i.min(j),
+ }
+}
+
+fn pair_sort_key(
group: &GroupState,
- components: &HashMap<ItemId, usize>,
+ pool: &[ItemId],
+ layout: &ComponentLayout,
a: &ItemId,
b: &ItemId,
-) -> PairPriority {
+) -> PairSortKey {
let voted = pair_is_voted(group, a, b);
- let bridge = components.get(a) != components.get(b);
- match (bridge, voted) {
+ let bridge = layout.ids.get(a) != layout.ids.get(b);
+ let priority = match (bridge, voted) {
(true, false) => PairPriority::BridgeUnvoted,
(false, false) => PairPriority::WithinUnvoted,
(true, true) => PairPriority::BridgeVoted,
(false, true) => PairPriority::WithinVoted,
+ };
+ let bridge_sub = if priority == PairPriority::BridgeUnvoted {
+ bridge_sub_priority(layout, a, b)
+ } else {
+ BridgeSubPriority::MergeEstablished
+ };
+ let within_sub = if matches!(
+ priority,
+ PairPriority::WithinUnvoted | PairPriority::WithinVoted
+ ) {
+ within_sub_priority(group, pool, layout, a, b)
+ } else {
+ WITHIN_SUB_WORST
+ };
+ PairSortKey {
+ priority,
+ bridge_sub,
+ within_sub,
}
}
@@ -109,9 +247,12 @@ fn candidate_pairs(pool: &[ItemId], exclude: Option<(&ItemId, &ItemId)>) -> Vec<
/// Pick the next pair to vote on within `pool`.
///
-/// 1. Prefer unvoted **bridge** pairs (connect separate ranking components).
-/// 2. Then unvoted within-component pairs (refinement).
-/// 3. Then already-voted pairs (re-compare).
+/// 1. Prefer unvoted **bridge** pairs (connect separate ranking components),
+/// with sub-priority: merge established components, attach an isolate to
+/// established, then compare two isolates.
+/// 2. Then unvoted within-component pairs; when the pool is one connected group,
+/// prefer adjacent ranks (1 vs 2, 2 vs 3, …) in order, skipping voted pairs.
+/// 3. Then already-voted pairs (re-compare), with the same zip ordering.
pub fn suggest_next_pair_in_pool(
group: &GroupState,
pool: &[ItemId],
@@ -121,15 +262,15 @@ pub fn suggest_next_pair_in_pool(
if candidates.is_empty() {
return None;
}
- let components = component_ids(group, pool);
+ let layout = component_layout(group, pool);
let best = candidates
.iter()
- .map(|(a, b)| (pair_priority(group, &components, a, b), (a, b)))
- .min_by_key(|(p, _)| *p)?
+ .map(|(a, b)| (pair_sort_key(group, pool, &layout, a, b), (a, b)))
+ .min_by_key(|(k, _)| *k)?
.0;
let best_pairs: Vec<(ItemId, ItemId)> = candidates
.into_iter()
- .filter(|(a, b)| pair_priority(group, &components, a, b) == best)
+ .filter(|(a, b)| pair_sort_key(group, pool, &layout, a, b) == best)
.collect();
best_pairs.choose(&mut rand::thread_rng()).cloned()
}
@@ -303,6 +444,38 @@ mod tests {
assert!(from_ab && from_cd, "expected bridge pair, got {:?}", chosen);
}
+ #[test]
+ fn suggest_prefers_attach_over_isolate_pair_among_many_unranked() {
+ let parent = ItemId::parse("reddit.com/r/rust").unwrap();
+ let mut tree = seed_children(
+ &parent,
+ &[
+ "reddit.com/r/rust/a",
+ "reddit.com/r/rust/b",
+ "reddit.com/r/rust/c",
+ "reddit.com/r/rust/d",
+ "reddit.com/r/rust/e",
+ ],
+ );
+ let ab =
+ VoteData::from_recorded(1, "reddit.com/r/rust/a", "reddit.com/r/rust/b", 2, 1).unwrap();
+ tree.apply_vote(&parent, ab);
+ let group = tree.get(&parent).unwrap().local_ranking.clone();
+ let pool = children_of(&tree, &parent);
+ let pair = suggest_next_pair_in_pool(&group, &pool, None).unwrap();
+ let chosen = pair_set(&pair);
+ let from_ab =
+ chosen.contains("reddit.com/r/rust/a") || chosen.contains("reddit.com/r/rust/b");
+ let from_cde = chosen.contains("reddit.com/r/rust/c")
+ || chosen.contains("reddit.com/r/rust/d")
+ || chosen.contains("reddit.com/r/rust/e");
+ assert!(
+ from_ab && from_cde,
+ "expected ranked+unranked attach, got {:?}",
+ chosen
+ );
+ }
+
#[test]
fn suggest_connects_isolate_to_existing_component() {
let parent = ItemId::parse("reddit.com/r/rust").unwrap();
@@ -325,6 +498,65 @@ mod tests {
assert!(chosen.contains("reddit.com/r/rust/a") || chosen.contains("reddit.com/r/rust/b"));
}
+ #[test]
+ fn suggest_zips_adjacent_ranks_when_tree_complete() {
+ let parent = ItemId::parse("reddit.com/r/rust").unwrap();
+ let mut tree = seed_children(
+ &parent,
+ &[
+ "reddit.com/r/rust/a",
+ "reddit.com/r/rust/b",
+ "reddit.com/r/rust/c",
+ ],
+ );
+ // Star at a connects all three; b-c is the only unvoted adjacent pair left.
+ for (a, b, l, r) in [
+ ("reddit.com/r/rust/a", "reddit.com/r/rust/b", 3, 1),
+ ("reddit.com/r/rust/a", "reddit.com/r/rust/c", 2, 1),
+ ] {
+ let v = VoteData::from_recorded(1, a, b, l, r).unwrap();
+ tree.apply_vote(&parent, v);
+ }
+ let group = tree.get(&parent).unwrap().local_ranking.clone();
+ let pool = children_of(&tree, &parent);
+ let pair = suggest_next_pair_in_pool(&group, &pool, None).unwrap();
+ let chosen = pair_set(&pair);
+ // a-b and a-c voted;
… preview truncated; 1,687 characters omittedB — c_f515f8a12d7a (tommy-mor)
message
[601d3a05] fix(html): drop home toolbar + and ExpandNewThreadForm (single + flow) Public home now SSRs #new-thread-ui-slot like room pages: collapsed compose for signed-in users, login hint when logged out. Removes the extra toolbar that morphed the same collapsed state and the expand_new_thread_form action. Made-with: Cursor
diff preview
diff --git a/server/src/api/ui_html.rs b/server/src/api/ui_html.rs
index e979053ff1ba8c0e2bf55add0a32b7de11cf1e56..f3ce5cb2ab2f923440a8479d0f1fb4acbba166ca 100644
--- a/server/src/api/ui_html.rs
+++ b/server/src/api/ui_html.rs
@@ -139,51 +139,6 @@ async fn dispatch_ui_action(
}
}
}
- HtmlUiAction::ExpandNewThreadForm { room_wire } => {
- let room_wire = room_wire.trim().to_string();
- if room_wire.is_empty() {
- return ui_js_warn("missing room").into_response();
- }
- if room_wire == "public" {
- let reduced = state.reduced.read().await;
- let user = session.map(|s| s.username.as_str());
- drop(reduced);
- let markup = if user.is_some() {
- fragment_new_thread_slot(&ThreadNav::public(), true, false)
- } else {
- login_to_post_hint_markup()
- };
- return JsBuilder::new()
- .morph_inner_selector("#new-thread-ui-slot", markup)
- .into_response();
- }
- let reduced = state.reduced.read().await;
- let user = session.map(|s| s.username.as_str());
- if !reduced.rooms.contains(&room_wire) {
- drop(reduced);
- return ui_js_warn("room not found").into_response();
- }
- if !user_can_view_room(&reduced, &room_wire, user) {
- drop(reduced);
- return ui_js_warn("forbidden").into_response();
- }
- let can_post = session
- .as_ref()
- .map(|s| user_can_post_room(&reduced, &room_wire, &s.username))
- .unwrap_or(false);
- drop(reduced);
- let Some(nav) = ThreadNav::from_room_id(&room_wire) else {
- return ui_js_warn("bad room").into_response();
- };
- let markup = if can_post {
- fragment_new_thread_slot(&nav, true, false)
- } else {
- login_to_post_hint_markup()
- };
- JsBuilder::new()
- .morph_inner_selector("#new-thread-ui-slot", markup)
- .into_response()
- }
HtmlUiAction::SetRoomMembersExpanded { room_wire, expanded } => {
let room_wire = room_wire.trim().to_string();
if room_wire.is_empty() {
diff --git a/server/src/html/forum/feed.rs b/server/src/html/forum/feed.rs
index 1b4ae7baa3ad4757b74172d7b67f3f2b33d1075d..945bdd6c48bc164e2cf91fd0996c4321b75f5abf 100644
--- a/server/src/html/forum/feed.rs
+++ b/server/src/html/forum/feed.rs
@@ -14,6 +14,7 @@ use crate::timeago;
use super::ingest::ingest_entry_markup;
use super::nav::ThreadNav;
+use super::new_thread::{fragment_new_thread_slot, login_to_post_hint_markup};
use super::page::auth_strip;
use super::paginator::{render_thread_paginator, PAGE_SIZE};
use crate::html::{
@@ -217,9 +218,6 @@ pub async fn home(
let strip = auth_strip(&headers, &jar, &reduced_read);
drop(reduced_read);
- use crate::html::ui_action::{HtmlUiAction, UI_RPC_FIELD};
- use crate::form_template::template_json_compact;
-
let page = layout(
"slug.social",
"view-thread",
@@ -243,15 +241,13 @@ pub async fn home(
}
}
p class="muted" { "dark = time-ordered · light = vote-ranked" }
- div class="thread-feed-toolbar" {
- form method="POST" action="/ui" {
- input type="hidden" name=(UI_RPC_FIELD) value=(template_json_compact(&HtmlUiAction::ExpandNewThreadForm {
- room_wire: "public".into(),
- }).expect("static json"));
- button type="submit" class="section-add-btn" { "+" }
+ div id="new-thread-ui-slot" {
+ @if user.is_some() {
+ (fragment_new_thread_slot(&nav, true, false))
+ } @else {
+ (login_to_post_hint_markup())
}
}
- div id="new-thread-ui-slot" {}
(render_thread_feed(Some(&nav), "thread-feed", &public_rows, now))
(cli_panel(&["npx slugsocial public forum list"]))
},
diff --git a/server/src/html/ui_action.rs b/server/src/html/ui_action.rs
index 5031ebfeb928f28e471f23210b8c644654adb7c7..da0c9b3541e8e4988a78768cddef22324755c3f2 100644
--- a/server/src/html/ui_action.rs
+++ b/server/src/html/ui_action.rs
@@ -38,11 +38,6 @@ pub enum HtmlUiAction {
RedactPost {
post_id: String,
},
- /// Morph `#new-thread-ui-slot` inner to the collapsed compose toggle (or login hint).
- /// Use `room_wire: "public"` for the public forum home; otherwise a private room id (`short/slug`).
- ExpandNewThreadForm {
- room_wire: String,
- },
/// Morph `#room-members-section` — members list open or collapsed (server-rendered).
SetRoomMembersExpanded {
room_wire: String,
@@ -131,26 +126,6 @@ mod tests {
);
}
- #[test]
- fn expand_new_thread_form_public() {
- let template = serde_json::json!({
- "action": "expand_new_thread_form",
- "room_wire": "public",
- });
- let mut form = HashMap::new();
- form.insert(
- UI_RPC_FIELD.to_string(),
- serde_json::to_string(&template).unwrap(),
- );
- let a = parse_html_ui_from_form(&form).unwrap();
- assert_eq!(
- a,
- HtmlUiAction::ExpandNewThreadForm {
- room_wire: "public".into(),
- }
- );
- }
-
#[test]
fn expand_post_full_round_trip() {
let template = serde_json::json!({
Hardlinks — judgments / attempts / prompt
judgments
attempts
Prompt text is loaded only by the download route.