refactor how repl works

internal/compiler/compiler.go

@@ -25,8 +25,11 @@ type CompilationScope struct {
 type Compiler struct {
 	Debug bool
 
+	fn    string
+	input string
+
 	l         int
-	constants []object.Object
+	constants *[]object.Object
 
 	symbolTable *SymbolTable
 
@@ -48,7 +51,7 @@ func New() *Compiler {
 	}
 
 	return &Compiler{
-		constants:   []object.Object{},
+		constants:   &[]object.Object{},
 		symbolTable: symbolTable,
 		scopes:      []CompilationScope{mainScope},
 		scopeIndex:  0,
@@ -59,7 +62,7 @@ func (c *Compiler) currentInstructions() code.Instructions {
 	return c.scopes[c.scopeIndex].instructions
 }
 
-func NewWithState(s *SymbolTable, constants []object.Object) *Compiler {
+func NewWithState(s *SymbolTable, constants *[]object.Object) *Compiler {
 	compiler := New()
 	compiler.symbolTable = s
 	compiler.constants = constants
@@ -442,7 +445,7 @@ func (c *Compiler) Compile(node ast.Node) error {
 		}
 
 		freeSymbols := c.symbolTable.FreeSymbols
-		numLocals := c.symbolTable.numDefinitions
+		numLocals := c.symbolTable.NumDefinitions
 		instructions := c.leaveScope()
 
 		for _, s := range freeSymbols {
@@ -529,8 +532,8 @@ func (c *Compiler) Compile(node ast.Node) error {
 }
 
 func (c *Compiler) addConstant(obj object.Object) int {
-	c.constants = append(c.constants, obj)
-	return len(c.constants) - 1
+	*c.constants = append(*c.constants, obj)
+	return len(*c.constants) - 1
 }
 
 func (c *Compiler) emit(op code.Opcode, operands ...int) int {
@@ -542,6 +545,11 @@ func (c *Compiler) emit(op code.Opcode, operands ...int) int {
 	return pos
 }
 
+func (c *Compiler) SetFileInfo(fn, input string) {
+	c.fn = fn
+	c.input = input
+}
+
 func (c *Compiler) setLastInstruction(op code.Opcode, pos int) {
 	previous := c.scopes[c.scopeIndex].lastInstruction
 	last := EmittedInstruction{Opcode: op, Position: pos}
@@ -553,7 +561,7 @@ func (c *Compiler) setLastInstruction(op code.Opcode, pos int) {
 func (c *Compiler) Bytecode() *Bytecode {
 	return &Bytecode{
 		Instructions: c.currentInstructions(),
-		Constants:    c.constants,
+		Constants:    *c.constants,
 	}
 }
 
@@ -630,11 +638,6 @@ func (c *Compiler) replaceLastPopWithReturn() {
 	c.scopes[c.scopeIndex].lastInstruction.Opcode = code.OpReturn
 }
 
-type Bytecode struct {
-	Instructions code.Instructions
-	Constants    []object.Object
-}
-
 func (c *Compiler) loadSymbol(s Symbol) {
 	switch s.Scope {
 	case GlobalScope: