5 files changed, 179 insertions, 0 deletions
diff --git a/lua/day2.lua b/lua/day2.lua
new file mode 100644
index 0000000..0526d78
--- /dev/null
+++ b/lua/day2.lua
@@ -0,0 +1,79 @@
+dofile("util.lua")
+
+ice_cream_scoops = {
+   "vanilla",
+   "chocolate";
+
+   sprinkles = true
+}
+
+greek_numbers = {
+   ena = "one",
+   dyo = "two",
+   tria = "three"
+}
+
+mt = {
+   __tostring = table_to_string
+}
+
+setmetatable(greek_numbers, mt)
+
+Villain = {
+   health = 100,
+
+   new = function(self, name)
+      obj = {
+         name = name,
+         health = self.health
+      }
+      setmetatable(obj, self)
+      self.__index = self
+      return obj
+   end,
+
+   take_hit = function(self)
+      self.health = self.health - 10
+   end
+}
+
+dietrich = Villain:new("Dietrich")
+
+SuperVillain = Villain:new()
+function SuperVillain:take_hit()
+   self.health = self.health - 5
+end
+
+joker = SuperVillain:new("Joker")
+
+function fibonacci()
+   local m = 1
+   local n = 1
+
+   while true do
+      coroutine.yield(m)
+      m, n = n, m+n
+   end
+end
+
+generator = coroutine.create(fibonacci)
+
+-- Easy
+function concatenate(a1, a2)
+   local new = {}
+   for i = 1, #a1 do
+      new[#new+1] = a1[i]
+   end
+   for i = 1, #a2 do
+      new[#new+1] = a2[i]
+   end
+   return new
+end
+
+l1 = {1,2,3}
+l2 = {4,5,6,7,8}
+
+-- Medium -- ????????????????????????????
+-- function _G.__add(self, v)
+--    return concatenate(self, v)
+-- end
diff --git a/lua/punch.lua b/lua/punch.lua
new file mode 100644
index 0000000..8f8b24f
--- /dev/null
+++ b/lua/punch.lua
@@ -0,0 +1,20 @@
+dofile("scheduler.lua")
+
+function punch()
+   for i = 1, 5 do
+      print('punch ' .. i)
+      wait(1.0)
+   end
+end
+
+function block()
+   for i = 1, 3 do
+      print('block ' .. i)
+      wait(2.0)
+   end
+end
+
+schedule(0.0, coroutine.create(punch))
+schedule(0.0, coroutine.create(block))
+
+run()
diff --git a/lua/scheduler.lua b/lua/scheduler.lua
new file mode 100644
index 0000000..e526efa
--- /dev/null
+++ b/lua/scheduler.lua
@@ -0,0 +1,39 @@
+pending = {}
+
+function schedule(time, action)
+   pending[#pending+1] = {
+      time = time,
+      action = action
+   }
+
+   sort_by_time(pending)
+end
+
+function sort_by_time(array)
+   table.sort(array, function(e1, e2) return e1.time < e2.time end)
+end
+
+function wait(seconds)
+   coroutine.yield(seconds)
+end
+
+function run()
+   while #pending > 0 do
+      while os.clock() < pending[1].time do end -- busy-wait
+
+      local item = remove_first(pending)
+      local _, seconds = coroutine.resume(item.action)
+
+      if seconds then
+         later = os.clock() + seconds
+         schedule(later, item.action)
+      end
+   end
+end
+
+function remove_first(array)
+   result = array[1]
+   array[1] = array[#array]
+   array[#array] = nil
+   return result
+end
diff --git a/lua/strict.lua b/lua/strict.lua
new file mode 100644
index 0000000..1c70442
--- /dev/null
+++ b/lua/strict.lua
@@ -0,0 +1,25 @@
+local _private = {}
+
+function strict_read(table, key)
+   if _private[key] then
+      return _private[key]
+   else
+      error("Invalid key: " .. key)
+   end
+end
+
+function strict_write(table, key, value)
+   if _private[key] then
+      error("Duplicate key: " .. key)
+   else
+      _private[key] = value
+   end
+end
+
+local mt = {
+   __index = strict_read,
+   __newindex = strict_write
+}
+
+treasure = {}
+setmetatable(treasure, mt)
diff --git a/lua/util.lua b/lua/util.lua
new file mode 100644
index 0000000..e68c615
--- /dev/null
+++ b/lua/util.lua
@@ -0,0 +1,16 @@
+function print_table(t)
+   for k, v in pairs(t) do
+      print(k .. ": " .. v)
+   end
+end
+
+function table_to_string(t)
+   local result = {}
+
+   for k, v in pairs(t) do
+      result[#result+1] = k .. ": " .. v
+   end
+
+   return table.concat(result, "\n")
+end
+