refactor how repl works

internal/vm/vm.go

@@ -2,7 +2,6 @@ package vm
 
 import (
 	"fmt"
-	"io/ioutil"
 	"log"
 	"monkey/internal/builtins"
 	"monkey/internal/code"
@@ -11,6 +10,8 @@ import (
 	"monkey/internal/object"
 	"monkey/internal/parser"
 	"monkey/internal/utils"
+	"os"
+	"path/filepath"
 	"strings"
 	"unicode"
 )
@@ -30,20 +31,20 @@ func ExecModule(name string, state *VMState) (object.Object, error) {
 		return nil, fmt.Errorf("ImportError: no module named '%s'", name)
 	}
 
-	b, err := ioutil.ReadFile(filename)
+	b, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, fmt.Errorf("IOError: error reading module '%s': %s", name, err)
 	}
 
 	l := lexer.New(string(b))
-	p := parser.New(l)
+	p := parser.New(fmt.Sprintf("<module %s>", name), l)
 
 	module := p.ParseProgram()
 	if len(p.Errors()) != 0 {
 		return nil, fmt.Errorf("ParseError: %s", p.Errors())
 	}
 
-	c := compiler.NewWithState(state.Symbols, state.Constants)
+	c := compiler.NewWithState(state.Symbols, &state.Constants)
 	err = c.Compile(module)
 	if err != nil {
 		return nil, fmt.Errorf("CompileError: %s", err)
@@ -52,7 +53,7 @@ func ExecModule(name string, state *VMState) (object.Object, error) {
 	code := c.Bytecode()
 	state.Constants = code.Constants
 
-	machine := NewWithState(code, state)
+	machine := NewWithState(fmt.Sprintf("<module %s>", name), code, state)
 	err = machine.Run()
 	if err != nil {
 		return nil, fmt.Errorf("RuntimeError: error loading module '%s'", err)
@@ -102,6 +103,9 @@ type VM struct {
 
 	state *VMState
 
+	dir  string
+	file string
+
 	stack []object.Object
 	sp    int // Always points to the next value. Top of stack is stack[sp-1]
 
@@ -111,7 +115,7 @@ type VM struct {
 }
 
 // New constructs a new monkey-lang bytecode virtual machine
-func New(bytecode *compiler.Bytecode) *VM {
+func New(fn string, bytecode *compiler.Bytecode) *VM {
 	mainFn := &object.CompiledFunction{Instructions: bytecode.Instructions}
 	mainClosure := &object.Closure{Fn: mainFn}
 	mainFrame := NewFrame(mainClosure, 0)
@@ -122,7 +126,7 @@ func New(bytecode *compiler.Bytecode) *VM {
 	state := NewVMState()
 	state.Constants = bytecode.Constants
 
-	return &VM{
+	vm := &VM{
 		state: state,
 
 		stack: make([]object.Object, StackSize),
@@ -132,9 +136,13 @@ func New(bytecode *compiler.Bytecode) *VM {
 		frame:  mainFrame,
 		fp:     1,
 	}
+
+	vm.dir, vm.file = filepath.Split(fn)
+
+	return vm
 }
 
-func NewWithState(bytecode *compiler.Bytecode, state *VMState) *VM {
+func NewWithState(fn string, bytecode *compiler.Bytecode, state *VMState) *VM {
 	mainFn := &object.CompiledFunction{Instructions: bytecode.Instructions}
 	mainClosure := &object.Closure{Fn: mainFn}
 	mainFrame := NewFrame(mainClosure, 0)
@@ -142,7 +150,7 @@ func NewWithState(bytecode *compiler.Bytecode, state *VMState) *VM {
 	frames := make([]*Frame, MaxFrames)
 	frames[0] = mainFrame
 
-	return &VM{
+	vm := &VM{
 		state: state,
 
 		frames: frames,
@@ -152,6 +160,10 @@ func NewWithState(bytecode *compiler.Bytecode, state *VMState) *VM {
 		stack: make([]object.Object, StackSize),
 		sp:    0,
 	}
+
+	vm.dir, vm.file = filepath.Split(fn)
+
+	return vm
 }
 
 func (vm *VM) pushFrame(f *Frame) {
@@ -429,7 +441,7 @@ func (vm *VM) Run() error {
 
 		case code.OpGetBuiltin:
 			builtinIndex := code.ReadUint8(ins[ip+1:])
-			vm.frame.ip += 1
+			vm.frame.ip++
 
 			builtin := builtins.BuiltinsIndex[builtinIndex]