.

lua-temp/tyche-vm.lua

@@ -0,0 +1,87 @@
+local pprint = require('pprint')
+
+----------------------
+--                  --
+--      STACK       --
+--                  --
+----------------------
+
+local Stack = {}
+Stack.__index = Stack
+
+function Stack.new()
+    return setmetatable({
+        stack = {},
+        fps = { 0 },
+    }, Stack)
+end
+
+function Stack:top_fps()
+    return self.fps[#self.fps]
+end
+
+function Stack:push(value)
+    table.insert(self.stack, value)
+end
+
+function Stack:pop(value)
+    if #self.stack <= self:top_fps() then error("Stack underflow") end
+    local v = self.stack[#self.stack]
+    self.stack[#self.stack] = nil
+    return v
+end
+
+function Stack:peek(value)
+    if #self.stack <= self:top_fps() then error("Stack underflow") end
+    return self.stack[#self.stack]
+end
+
+Stack.__len = function(self)
+    return #self.stack - self:top_fps()
+end
+
+Stack.__index = function(self, key)
+    local idx = tonumber(key)
+    if idx then
+        if idx >= 0 then
+            return self.stack[self:top_fps() + idx + 1]
+        else
+            if self:top_fps() + #self.stack + idx < 0 then error("Stack access out of range") end
+            return self.stack[#self.stack + idx + 1]
+        end
+    else
+        return Stack[key]   -- other methods
+    end
+end
+
+Stack.__newindex = function(self, key, value)
+end
+
+function Stack:push_fp()
+end
+
+function Stack:pop_fp()
+end
+
+function Stack:fp_level()
+end
+
+function Stack:debug()
+end
+
+----------------------
+--                  --
+--       VM         --
+--                  --
+----------------------
+
+local VM = {}
+VM.__index = VM
+
+function VM.new()
+    return setmetatable({
+        stack = Stack.new()
+    }, VM)
+end
+
+return VM