initial commit

src/mods/Hooks.lua

@@ -0,0 +1,47 @@
+local Hooks = {}
+Hooks.__index = Hooks
+local unpack = table.unpack or unpack
+
+function Hooks.new()
+  return setmetatable({ chains = {}, sealed = false }, Hooks)
+end
+
+function Hooks:wrap(name, callback, priority)
+  assert(not self.sealed, "mod hooks are sealed")
+  assert(type(name) == "string" and name ~= "", "hook name is required")
+  assert(type(callback) == "function", "hook callback must be a function")
+  local chain = self.chains[name] or {}
+  self.chains[name] = chain
+  local entry = { callback = callback, priority = priority or 0 }
+  chain[#chain + 1] = entry
+  table.sort(chain, function(a, b) return a.priority > b.priority end)
+  return function()
+    for i, candidate in ipairs(chain) do
+      if candidate == entry then table.remove(chain, i) break end
+    end
+  end
+end
+
+function Hooks:call(name, vanilla, ...)
+  local chain = self.chains[name] or {}
+  local args = { ... }
+  local function run(index, current)
+    if index > #chain then return current(unpack(args)) end
+    return chain[index].callback(function(...)
+      local nextArgs = { ... }
+      if #nextArgs == 0 then return run(index + 1, current) end
+      local old = args
+      args = nextArgs
+      local result = run(index + 1, current)
+      args = old
+      return result
+    end, unpack(args))
+  end
+  return run(1, vanilla)
+end
+
+function Hooks:seal()
+  self.sealed = true
+end
+
+return Hooks