functions with bindings

compiler/compiler.go

@@ -193,8 +193,13 @@ func (c *Compiler) Compile(node ast.Node) error {
 		if err != nil {
 			return err
 		}
+
 		symbol := c.symbolTable.Define(node.Name.Value)
-		c.emit(code.OpSetGlobal, symbol.Index)
+		if symbol.Scope == GlobalScope {
+			c.emit(code.OpSetGlobal, symbol.Index)
+		} else {
+			c.emit(code.OpSetLocal, symbol.Index)
+		}
 
 	case *ast.Identifier:
 		symbol, ok := c.symbolTable.Resolve(node.Value)
@@ -202,7 +207,11 @@ func (c *Compiler) Compile(node ast.Node) error {
 			return fmt.Errorf("undefined varible %s", node.Value)
 		}
 
-		c.emit(code.OpGetGlobal, symbol.Index)
+		if symbol.Scope == GlobalScope {
+			c.emit(code.OpGetGlobal, symbol.Index)
+		} else {
+			c.emit(code.OpGetLocal, symbol.Index)
+		}
 
 	case *ast.StringLiteral:
 		str := &object.String{Value: node.Value}
@@ -268,9 +277,10 @@ func (c *Compiler) Compile(node ast.Node) error {
 			c.emit(code.OpReturn)
 		}
 
+		numLocals := c.symbolTable.numDefinitions
 		instructions := c.leaveScope()
 
-		compiledFn := &object.CompiledFunction{Instructions: instructions}
+		compiledFn := &object.CompiledFunction{Instructions: instructions, NumLocals: numLocals}
 		c.emit(code.OpConstant, c.addConstant(compiledFn))
 
 	case *ast.ReturnStatement:
@@ -374,6 +384,8 @@ func (c *Compiler) enterScope() {
 	}
 	c.scopes = append(c.scopes, scope)
 	c.scopeIndex++
+
+	c.symbolTable = NewEnclosedSymbolTable(c.symbolTable)
 }
 
 func (c *Compiler) leaveScope() code.Instructions {
@@ -382,6 +394,8 @@ func (c *Compiler) leaveScope() code.Instructions {
 	c.scopes = c.scopes[:len(c.scopes)-1]
 	c.scopeIndex--
 
+	c.symbolTable = c.symbolTable.Outer
+
 	return instructions
 }