1 files changed, 61 insertions, 0 deletions
diff --git a/core.lua b/core.lua
new file mode 100644
index 0000000..f8cd76b
--- /dev/null
+++ b/core.lua
@@ -0,0 +1,61 @@
+local core = {}
+
+--- Create a boolean toggle with on/off callbacks.
+function core.toggle(on, off)
+	local state = false
+	return {
+		set = function(v)
+			if v == state then
+				return state
+			end
+			state = not not v
+			if state then
+				on()
+			else
+				off()
+			end
+			return state
+		end,
+		get = function()
+			return state
+		end,
+		toggle = function(self)
+			return self.set(not state)
+		end,
+	}
+end
+
+--- Create a resettable timeout using blocking sleep (matches waywall execution model).
+--- Calls `f()` only if this invocation is the last one.
+function core.resettable_timeout(sleep, f)
+	local gen = 0
+	return function(delay_ms)
+		gen = gen + 1
+		local my = gen
+		sleep(delay_ms)
+		if my == gen then
+			f()
+		end
+	end
+end
+
+--- Shallow table copy
+function core.copy(t)
+	local r = {}
+	for k, v in pairs(t) do
+		r[k] = v
+	end
+	return r
+end
+
+--- Merge (dst gets missing fields from src)
+function core.merge(dst, src)
+	for k, v in pairs(src or {}) do
+		if dst[k] == nil then
+			dst[k] = v
+		end
+	end
+	return dst
+end
+
+return core