.

lua-temp/TODO.md

@@ -3,10 +3,11 @@ Progress of the Lua port:
 - [x] Assembler
 - [x] Basic VM execution
 - [x] Logic/arithmetic expressions
-- [ ] Functions
+- [ ] Variables
   - [ ] Local variables
+- [ ] Functions
   - [ ] Calling functions
-  - [ ] Globals
+  - [ ] Calling functions with parameters
 - [ ] Control flow
   - [ ] Lablels in Assembly
   - [ ] Recursion
@@ -19,6 +20,7 @@ Progress of the Lua port:
   - [ ] Garbage collection
   - [ ] Metatables
 - [ ] Real
+- [ ] Globals
 - [ ] Error handling
   - [ ] Stack traces in case of errors
 - [ ] Closures/upvalues

lua-temp/tests.lua

@@ -181,4 +181,20 @@ do TEST("VM: logic/arithmetic")
     assert_eq(arith(20, 3, 'mod'):to_integer(-1), 2)
 end
 
+do TEST("VM: local variables")
+    local vm = VM:new():load(assemble([[
+        .func 0
+            pushv 2         ; local a, b
+            pushi 3         ; a = 3
+            set   0
+            pushi 4         ; b = 4
+            set   1
+            dupv  0         ; return a
+            ret
+    ]])):call(0)
+
+    assert_eq(vm:stack_sz(), 1)
+    assert_eq(vm:to_integer(-1), 3)
+end
+
 print('End.')

lua-temp/tyche-vm.lua

@@ -21,6 +21,8 @@ function format_value(v)
         return '"' .. v.value .. '"'
     elseif v.type == 'function' then
         return '@' .. tostring(v.value)
+    elseif v.type == 'nil' then
+        return 'nil'
     else
         return pprint.format(v)
     end
@@ -49,7 +51,8 @@ function Stack:top_fps()
 end
 
 function Stack:push(value)
-    assert(type(value) == 'table' and TYPE_MAP[value.type])
+    assert(type(value) == 'table', "invalid value format (expected { type='...', value=... })")
+    assert(TYPE_MAP[value.type], "missing field 'type' in value")
     table.insert(self.stack, value)
 end
 
@@ -208,6 +211,11 @@ function VM.new()
     }, VM)
 end
 
+function VM:set_debug(b)
+    self.debug = b
+    return self
+end
+
 --
 -- code management
 --
@@ -226,6 +234,10 @@ function VM:push_integer(n)
     self.stack:push({ type = 'integer', value = n })
 end
 
+function VM:push_nil()
+    self.stack:push({ type = 'nil' })
+end
+
 --
 -- information
 --
@@ -281,6 +293,23 @@ function VM:_step()
     if op.operator == 'pushi' then
         self:push_integer(op.operand)
 
+    --
+    -- local variables
+    --
+
+    elseif op.operator == 'pushv' then
+        for i=1,op.operand do
+            self:push_nil()
+        end
+
+    elseif op.operator == 'set' then
+        local a = self.stack:pop()
+        self.stack[op.operand + 1] = a
+
+    elseif op.operator == 'dupv' then
+        local a = self.stack[op.operand + 1]
+        self.stack:push(a)
+
     --
     -- logic/arithmetic operations
     --