feat: extend items with Items.tome and Items.amulet

src/leaderboard.lua

@@ -0,0 +1,55 @@
+-- Persistent top-N high score table. A run's own numeric score (see
+-- morgue.lua's Morgue.score) only matters across runs if something
+-- remembers it - this is that memory, carried inside meta.lua's own save
+-- file exactly like renown and achievements already are, so a leaderboard
+-- outlives every single run that fed it.
+
+local Leaderboard = {}
+
+Leaderboard.CAPACITY = 10
+
+function Leaderboard.new()
+  return {}
+end
+
+-- Shifts board's tail down to open a gap for `entry` at the first slot
+-- whose current occupant does not outscore it, then drops it there.
+-- Returns the 1-based rank entry lands at, counting past Leaderboard.CAPACITY
+-- when the board is already full - the caller trims that overflow back off.
+local function insertSorted(board, entry)
+  local i = #board + 1
+  while i > 1 and board[i - 1].score < entry.score do
+    board[i] = board[i - 1]
+    i = i - 1
+  end
+  board[i] = entry
+  return i
+end
+
+-- Inserts `entry` (expects at least a numeric .score field) into `board`,
+-- keeping it sorted best-score-first and capped at Leaderboard.CAPACITY.
+-- A run that does not crack the cap is dropped outright rather than kept
+-- around uncounted - a leaderboard only remembers what actually placed.
+-- Returns the rank it landed at, or nil if it did not make the cut.
+function Leaderboard.record(board, entry)
+  local rank = insertSorted(board, entry)
+  while #board > Leaderboard.CAPACITY do
+    table.remove(board)
+  end
+  if rank > Leaderboard.CAPACITY then return nil end
+  return rank
+end
+
+function Leaderboard.top(board, count)
+  local out = {}
+  for i = 1, math.min(count or Leaderboard.CAPACITY, #board) do
+    out[i] = board[i]
+  end
+  return out
+end
+
+function Leaderboard.bestScore(board)
+  return board[1] and board[1].score or 0
+end
+
+return Leaderboard