rearrange builtins

object/array.go

@@ -0,0 +1,51 @@
+package object
+
+import (
+	"bytes"
+	"strings"
+)
+
+// Array is the array literal type that holds a slice of Object(s)
+type Array struct {
+	Elements []Object
+}
+
+func (ao *Array) Type() ObjectType {
+	return ARRAY_OBJ
+}
+func (ao *Array) Inspect() string {
+	var out bytes.Buffer
+
+	var elements []string
+	for _, e := range ao.Elements {
+		elements = append(elements, e.Inspect())
+	}
+
+	out.WriteString("[")
+	out.WriteString(strings.Join(elements, ", "))
+	out.WriteString("]")
+
+	return out.String()
+}
+func (ao *Array) String() string {
+	return ao.Inspect()
+}
+func (ao *Array) Equal(other Object) bool {
+	if obj, ok := other.(*Array); ok {
+		if len(ao.Elements) != len(obj.Elements) {
+			return false
+		}
+		for i, el := range ao.Elements {
+			cmp, ok := el.(Comparable)
+			if !ok {
+				return false
+			}
+			if !cmp.Equal(obj.Elements[i]) {
+				return false
+			}
+		}
+
+		return true
+	}
+	return false
+}

object/bool.go

@@ -0,0 +1,28 @@
+package object
+
+import (
+	"fmt"
+)
+
+type Boolean struct {
+	Value bool
+}
+
+func (b *Boolean) Type() ObjectType {
+	return BOOLEAN_OBJ
+}
+func (b *Boolean) Inspect() string {
+	return fmt.Sprintf("%t", b.Value)
+}
+func (b *Boolean) Clone() Object {
+	return &Boolean{Value: b.Value}
+}
+func (b *Boolean) String() string {
+	return b.Inspect()
+}
+func (b *Boolean) Equal(other Object) bool {
+	if obj, ok := other.(*Boolean); ok {
+		return b.Value == obj.Value
+	}
+	return false
+}

object/builtin.go

@@ -0,0 +1,18 @@
+package object
+
+import "fmt"
+
+type Builtin struct {
+	Name string
+	Fn   BuiltinFunction
+}
+
+func (b *Builtin) Type() ObjectType {
+	return BUILTIN_OBJ
+}
+func (b *Builtin) Inspect() string {
+	return fmt.Sprintf("<built-in function %s>", b.Name)
+}
+func (b *Builtin) String() string {
+	return b.Inspect()
+}

object/builtin_args.go

@@ -1,10 +0,0 @@
-package object
-
-// Args  ...
-func Args(args ...Object) Object {
-	elements := make([]Object, len(Arguments))
-	for i, arg := range Arguments {
-		elements[i] = &String{Value: arg}
-	}
-	return &Array{Elements: elements}
-}

object/builtin_assert.go

@@ -1,29 +0,0 @@
-package object
-
-import (
-	"fmt"
-	"os"
-)
-
-// Assert ...
-func Assert(args ...Object) Object {
-	if len(args) != 2 {
-		return newError("wrong number of arguments. got=%d, want=2",
-			len(args))
-	}
-	if args[0].Type() != BOOLEAN_OBJ {
-		return newError("argument #1 to `assert` must be BOOLEAN, got %s",
-			args[0].Type())
-	}
-	if args[1].Type() != STRING_OBJ {
-		return newError("argument #2 to `assert` must be STRING, got %s",
-			args[0].Type())
-	}
-
-	if !args[0].(*Boolean).Value {
-		fmt.Printf("Assertion Error: %s", args[1].(*String).Value)
-		os.Exit(1)
-	}
-
-	return nil
-}

object/builtin_bool.go

@@ -1,38 +0,0 @@
-package object
-
-// Bool ...
-func Bool(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1", len(args))
-	}
-
-	switch arg := args[0].(type) {
-	case *Null:
-		return &Boolean{Value: false}
-	case *Boolean:
-		return arg
-	case *Integer:
-		if arg.Value == 0 {
-			return &Boolean{Value: false}
-		}
-		return &Boolean{Value: true}
-	case *String:
-		if len(arg.Value) > 0 {
-			return &Boolean{Value: true}
-		}
-		return &Boolean{Value: false}
-	case *Array:
-		if len(arg.Elements) > 0 {
-			return &Boolean{Value: true}
-		}
-		return &Boolean{Value: false}
-	case *Hash:
-		if len(arg.Pairs) > 0 {
-			return &Boolean{Value: true}
-		}
-		return &Boolean{Value: false}
-
-	default:
-		return newError("argument to `bool` not supported, got=%s", args[0].Type())
-	}
-}

object/builtin_exit.go

@@ -1,17 +0,0 @@
-package object
-
-// Exit ...
-func Exit(args ...Object) Object {
-	var status int
-	if len(args) == 1 {
-		if args[0].Type() != INTEGER_OBJ {
-			return newError("argument to `exit` must be INTEGER, got %s",
-				args[0].Type())
-		}
-		status = int(args[0].(*Integer).Value)
-	}
-
-	ExitFunction(status)
-
-	return nil
-}

object/builtin_find.go

@@ -1,34 +0,0 @@
-package object
-
-import (
-	"strings"
-)
-
-// Find ...
-func Find(args ...Object) Object {
-	if len(args) != 2 {
-		return newError("wrong number of arguments. got=%d, want=2",
-			len(args))
-	}
-
-	if haystack, ok := args[0].(*String); ok {
-		if needle, ok := args[1].(*String); ok {
-			index := strings.Index(haystack.Value, needle.Value)
-			return &Integer{Value: int64(index)}
-		} else {
-			return newError("expected arg #2 to be `str` got got=%T", args[1])
-		}
-	} else if haystack, ok := args[0].(*Array); ok {
-		needle := args[1]
-		index := -1
-		for i, el := range haystack.Elements {
-			if cmp, ok := el.(Comparable); ok && cmp.Equal(needle) {
-				index = i
-				break
-			}
-		}
-		return &Integer{Value: int64(index)}
-	} else {
-		return newError("expected arg #1 to be `str` or `array` got got=%T", args[0])
-	}
-}

object/builtin_first.go

@@ -1,20 +0,0 @@
-package object
-
-// First ...
-func First(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-	if args[0].Type() != ARRAY_OBJ {
-		return newError("argument to `first` must be array, got %s",
-			args[0].Type())
-	}
-
-	arr := args[0].(*Array)
-	if len(arr.Elements) > 0 {
-		return arr.Elements[0]
-	}
-
-	return nil
-}

object/builtin_input.go

@@ -1,30 +0,0 @@
-package object
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"os"
-)
-
-// Input ...
-func Input(args ...Object) Object {
-	if len(args) > 0 {
-		obj, ok := args[0].(*String)
-		if !ok {
-			return newError(
-				"argument to `input` not supported, got %s",
-				args[0].Type(),
-			)
-		}
-		fmt.Fprintf(os.Stdout, obj.Value)
-	}
-
-	buffer := bufio.NewReader(os.Stdin)
-
-	line, _, err := buffer.ReadLine()
-	if err != nil && err != io.EOF {
-		return newError(fmt.Sprintf("error reading input from stdin: %s", err))
-	}
-	return &String{Value: string(line)}
-}

object/builtin_int.go

@@ -1,29 +0,0 @@
-package object
-
-import "strconv"
-
-// Int ...
-func Int(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1", len(args))
-	}
-
-	switch arg := args[0].(type) {
-	case *Boolean:
-		if arg.Value {
-			return &Integer{Value: 1}
-		}
-		return &Integer{Value: 0}
-	case *Integer:
-		return arg
-	case *String:
-		n, err := strconv.ParseInt(arg.Value, 10, 64)
-		if err != nil {
-			return newError("could not parse string to int: %s", err)
-		}
-
-		return &Integer{Value: n}
-	default:
-		return newError("argument to `int` not supported, got=%s", args[0].Type())
-	}
-}

object/builtin_join.go

@@ -1,27 +0,0 @@
-package object
-
-import (
-	"strings"
-)
-
-// Join ...
-func Join(args ...Object) Object {
-	if len(args) != 2 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	if arr, ok := args[0].(*Array); ok {
-		if sep, ok := args[1].(*String); ok {
-			a := make([]string, len(arr.Elements))
-			for i, el := range arr.Elements {
-				a[i] = el.String()
-			}
-			return &String{Value: strings.Join(a, sep.Value)}
-		} else {
-			return newError("expected arg #2 to be `str` got got=%T", args[1])
-		}
-	} else {
-		return newError("expected arg #1 to be `array` got got=%T", args[0])
-	}
-}

object/builtin_last.go

@@ -1,21 +0,0 @@
-package object
-
-// Last ...
-func Last(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-	if args[0].Type() != ARRAY_OBJ {
-		return newError("argument to `last` must be array, got %s",
-			args[0].Type())
-	}
-
-	arr := args[0].(*Array)
-	length := len(arr.Elements)
-	if length > 0 {
-		return arr.Elements[length-1]
-	}
-
-	return nil
-}

object/builtin_len.go

@@ -1,21 +0,0 @@
-package object
-
-import "unicode/utf8"
-
-// Len ...
-func Len(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	switch arg := args[0].(type) {
-	case *Array:
-		return &Integer{Value: int64(len(arg.Elements))}
-	case *String:
-		return &Integer{Value: int64(utf8.RuneCountInString(arg.Value))}
-	default:
-		return newError("argument to `len` not supported, got %s",
-			args[0].Type())
-	}
-}

object/builtin_lower.go

@@ -1,16 +0,0 @@
-package object
-
-import "strings"
-
-// Lower ...
-func Lower(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	if str, ok := args[0].(*String); ok {
-		return &String{Value: strings.ToLower(str.Value)}
-	}
-	return newError("expected `str` argument to `lower` got=%T", args[0])
-}

object/builtin_pop.go

@@ -1,25 +0,0 @@
-package object
-
-// Pop ...
-func Pop(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-	if args[0].Type() != ARRAY_OBJ {
-		return newError("argument to `pop` must be array, got %s",
-			args[0].Type())
-	}
-
-	arr := args[0].(*Array)
-	length := len(arr.Elements)
-
-	if length == 0 {
-		return newError("cannot pop from an empty array")
-	}
-
-	element := arr.Elements[length-1]
-	arr.Elements = arr.Elements[:length-1]
-
-	return element
-}

object/builtin_print.go

@@ -1,12 +0,0 @@
-package object
-
-import "fmt"
-
-// Print ...
-func Print(args ...Object) Object {
-	for _, arg := range args {
-		fmt.Println(arg.String())
-	}
-
-	return nil
-}

object/builtin_push.go

@@ -1,26 +0,0 @@
-package object
-
-// Push ...
-func Push(args ...Object) Object {
-	if len(args) != 2 {
-		return newError("wrong number of arguments. got=%d, want=2",
-			len(args))
-	}
-	if args[0].Type() != ARRAY_OBJ {
-		return newError("argument to `push` must be array, got %s",
-			args[0].Type())
-	}
-
-	arr := args[0].(*Array)
-	length := len(arr.Elements)
-
-	newElements := make([]Object, length+1)
-	copy(newElements, arr.Elements)
-	if immutable, ok := args[1].(Immutable); ok {
-		newElements[length] = immutable.Clone()
-	} else {
-		newElements[length] = args[1]
-	}
-
-	return &Array{Elements: newElements}
-}

object/builtin_read.go

@@ -1,26 +0,0 @@
-package object
-
-import (
-	"os"
-)
-
-// Read ...
-func Read(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	arg, ok := args[0].(*String)
-	if !ok {
-		return newError("argument to `read` expected to be `str` got=%T", args[0].Type())
-	}
-
-	filename := arg.Value
-	data, err := os.ReadFile(filename)
-	if err != nil {
-		return newError("error reading file: %s", err)
-	}
-
-	return &String{Value: string(data)}
-}

object/builtin_rest.go

@@ -1,23 +0,0 @@
-package object
-
-// Rest ...
-func Rest(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-	if args[0].Type() != ARRAY_OBJ {
-		return newError("argument to `rest` must be array, got %s",
-			args[0].Type())
-	}
-
-	arr := args[0].(*Array)
-	length := len(arr.Elements)
-	if length > 0 {
-		newElements := make([]Object, length-1, length-1)
-		copy(newElements, arr.Elements[1:length])
-		return &Array{Elements: newElements}
-	}
-
-	return nil
-}

object/builtin_split.go

@@ -1,36 +0,0 @@
-package object
-
-import (
-	"strings"
-)
-
-// Split ...
-func Split(args ...Object) Object {
-	if len(args) < 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	if obj, ok := args[0].(*String); ok {
-		var sep string
-
-		s := obj.Value
-
-		if len(args) == 2 {
-			if obj, ok := args[1].(*String); ok {
-				sep = obj.Value
-			} else {
-				return newError("expected arg #2 to be `str` got=%T", args[1])
-			}
-		}
-
-		tokens := strings.Split(s, sep)
-		elements := make([]Object, len(tokens))
-		for i, token := range tokens {
-			elements[i] = &String{Value: token}
-		}
-		return &Array{Elements: elements}
-	} else {
-		return newError("expected arg #1 to be `str` got got=%T", args[0])
-	}
-}

object/builtin_str.go

@@ -1,19 +0,0 @@
-package object
-
-import (
-	"fmt"
-)
-
-// Str ...
-func Str(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1", len(args))
-	}
-
-	arg, ok := args[0].(fmt.Stringer)
-	if !ok {
-		return newError("argument to `str` not supported, got %s", args[0].Type())
-	}
-
-	return &String{Value: arg.String()}
-}

object/builtin_typeof.go

@@ -1,10 +0,0 @@
-package object
-
-// TypeOf  ...
-func TypeOf(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1", len(args))
-	}
-
-	return &String{Value: string(args[0].Type())}
-}

object/builtin_upper.go

@@ -1,16 +0,0 @@
-package object
-
-import "strings"
-
-// Upper ...
-func Upper(args ...Object) Object {
-	if len(args) != 1 {
-		return newError("wrong number of arguments. got=%d, want=1",
-			len(args))
-	}
-
-	if str, ok := args[0].(*String); ok {
-		return &String{Value: strings.ToUpper(str.Value)}
-	}
-	return newError("expected `str` argument to `upper` got=%T", args[0])
-}

object/builtin_write.go

@@ -1,32 +0,0 @@
-package object
-
-import (
-	"os"
-)
-
-// Write ...
-func Write(args ...Object) Object {
-	if len(args) != 2 {
-		return newError("wrong number of arguments. got=%d, want=2",
-			len(args))
-	}
-
-	arg, ok := args[0].(*String)
-	if !ok {
-		return newError("argument #1 to `write` expected to be `str` got=%T", args[0].Type())
-	}
-	filename := arg.Value
-
-	arg, ok = args[1].(*String)
-	if !ok {
-		return newError("argument #2 to `write` expected to be `str` got=%T", args[1].Type())
-	}
-	data := []byte(arg.Value)
-
-	err := os.WriteFile(filename, data, 0755)
-	if err != nil {
-		return newError("error writing file: %s", err)
-	}
-
-	return &Null{}
-}

object/builtins.go

@@ -1,51 +0,0 @@
-package object
-
-import (
-	"fmt"
-	"sort"
-)
-
-// Builtins ...
-var Builtins = map[string]*Builtin{
-	"len":    {Name: "len", Fn: Len},
-	"input":  {Name: "input", Fn: Input},
-	"print":  {Name: "print", Fn: Print},
-	"first":  {Name: "first", Fn: First},
-	"last":   {Name: "last", Fn: Last},
-	"rest":   {Name: "rest", Fn: Rest},
-	"push":   {Name: "push", Fn: Push},
-	"pop":    {Name: "pop", Fn: Pop},
-	"exit":   {Name: "exit", Fn: Exit},
-	"assert": {Name: "assert", Fn: Assert},
-	"bool":   {Name: "bool", Fn: Bool},
-	"int":    {Name: "int", Fn: Int},
-	"str":    {Name: "str", Fn: Str},
-	"typeof": {Name: "typeof", Fn: TypeOf},
-	"args":   {Name: "args", Fn: Args},
-	"lower":  {Name: "lower", Fn: Lower},
-	"upper":  {Name: "upper", Fn: Upper},
-	"join":   {Name: "join", Fn: Join},
-	"split":  {Name: "split", Fn: Split},
-	"find":   {Name: "find", Fn: Find},
-	"read":   {Name: "read", Fn: Read},
-	"write":  {Name: "write", Fn: Write},
-}
-
-// BuiltinsIndex ...
-var BuiltinsIndex []*Builtin
-
-func init() {
-	var keys []string
-	for k := range Builtins {
-		keys = append(keys, k)
-	}
-	sort.Strings(keys)
-
-	for _, k := range keys {
-		BuiltinsIndex = append(BuiltinsIndex, Builtins[k])
-	}
-}
-
-func newError(format string, a ...interface{}) *Error {
-	return &Error{Message: fmt.Sprintf(format, a...)}
-}

object/closure.go

@@ -0,0 +1,37 @@
+package object
+
+import (
+	"fmt"
+	"monkey/code"
+)
+
+type CompiledFunction struct {
+	Instructions  code.Instructions
+	NumLocals     int
+	NumParameters int
+}
+
+func (cf *CompiledFunction) Type() ObjectType {
+	return COMPILED_FUNCTION_OBJ
+}
+func (cf *CompiledFunction) Inspect() string {
+	return fmt.Sprintf("CompiledFunction[%p]", cf)
+}
+func (cf *CompiledFunction) String() string {
+	return cf.Inspect()
+}
+
+type Closure struct {
+	Fn   *CompiledFunction
+	Free []Object
+}
+
+func (c *Closure) Type() ObjectType {
+	return CLOSURE_OBJ
+}
+func (c *Closure) Inspect() string {
+	return fmt.Sprintf("Closure[%p]", c)
+}
+func (c *Closure) String() string {
+	return c.Inspect()
+}

object/error.go

@@ -0,0 +1,18 @@
+package object
+
+type Error struct {
+	Message string
+}
+
+func (e *Error) Type() ObjectType {
+	return ERROR_OBJ
+}
+func (e *Error) Inspect() string {
+	return "Error: " + e.Message
+}
+func (e *Error) Clone() Object {
+	return &Error{Message: e.Message}
+}
+func (e *Error) String() string {
+	return e.Message
+}

object/function.go

@@ -0,0 +1,51 @@
+package object
+
+import (
+	"bytes"
+	"monkey/ast"
+	"strings"
+)
+
+type Function struct {
+	Parameters []*ast.Identifier
+	Body       *ast.BlockStatement
+	Env        *Environment
+}
+
+func (f *Function) Type() ObjectType {
+	return FUNCTION_OBJ
+}
+func (f *Function) Inspect() string {
+	var out bytes.Buffer
+
+	params := []string{}
+	for _, p := range f.Parameters {
+		params = append(params, p.String())
+	}
+
+	out.WriteString("fn")
+	out.WriteString("(")
+	out.WriteString(strings.Join(params, ", "))
+	out.WriteString(") {\n")
+	out.WriteString(f.Body.String())
+	out.WriteString("\n}")
+
+	return out.String()
+}
+func (f *Function) String() string {
+	return f.Inspect()
+}
+
+type ReturnValue struct {
+	Value Object
+}
+
+func (rv *ReturnValue) Type() ObjectType {
+	return RETURN_VALUE_OBJ
+}
+func (rv *ReturnValue) Inspect() string {
+	return rv.Value.Inspect()
+}
+func (rv *ReturnValue) String() string {
+	return rv.Inspect()
+}

object/hash.go

@@ -0,0 +1,91 @@
+package object
+
+import (
+	"bytes"
+	"fmt"
+	"hash/fnv"
+	"strings"
+)
+
+type HashKey struct {
+	Type  ObjectType
+	Value uint64
+}
+
+func (b *Boolean) HashKey() HashKey {
+	var value uint64
+
+	if b.Value {
+		value = 1
+	} else {
+		value = 0
+	}
+
+	return HashKey{Type: b.Type(), Value: value}
+}
+
+func (i *Integer) HashKey() HashKey {
+	return HashKey{Type: i.Type(), Value: uint64(i.Value)}
+}
+
+func (s *String) HashKey() HashKey {
+	h := fnv.New64a()
+	h.Write([]byte(s.Value))
+
+	return HashKey{Type: s.Type(), Value: h.Sum64()}
+}
+
+type HashPair struct {
+	Key   Object
+	Value Object
+}
+
+type Hash struct {
+	Pairs map[HashKey]HashPair
+}
+
+func (h *Hash) Type() ObjectType {
+	return HASH_OBJ
+}
+func (h *Hash) Inspect() string {
+	var out bytes.Buffer
+
+	pairs := []string{}
+	for _, pair := range h.Pairs {
+		pairs = append(pairs, fmt.Sprintf("%s: %s", pair.Key.Inspect(), pair.Value.Inspect()))
+	}
+
+	out.WriteString("{")
+	out.WriteString(strings.Join(pairs, ", "))
+	out.WriteString("}")
+
+	return out.String()
+}
+func (h *Hash) String() string {
+	return h.Inspect()
+}
+func (h *Hash) Equal(other Object) bool {
+	if obj, ok := other.(*Hash); ok {
+		if len(h.Pairs) != len(obj.Pairs) {
+			return false
+		}
+		for _, pair := range h.Pairs {
+			left := pair.Value
+			hashed := left.(Hashable)
+			right, ok := obj.Pairs[hashed.HashKey()]
+			if !ok {
+				return false
+			}
+			cmp, ok := left.(Comparable)
+			if !ok {
+				return false
+			}
+			if !cmp.Equal(right.Value) {
+				return false
+			}
+		}
+
+		return true
+	}
+	return false
+}

object/int.go

@@ -0,0 +1,26 @@
+package object
+
+import "fmt"
+
+type Integer struct {
+	Value int64
+}
+
+func (i *Integer) Type() ObjectType {
+	return INTEGER_OBJ
+}
+func (i *Integer) Inspect() string {
+	return fmt.Sprintf("%d", i.Value)
+}
+func (i *Integer) Clone() Object {
+	return &Integer{Value: i.Value}
+}
+func (i *Integer) String() string {
+	return i.Inspect()
+}
+func (i *Integer) Equal(other Object) bool {
+	if obj, ok := other.(*Integer); ok {
+		return i.Value == obj.Value
+	}
+	return false
+}

object/null.go

@@ -0,0 +1,17 @@
+package object
+
+type Null struct{}
+
+func (n *Null) Type() ObjectType {
+	return NULL_OBJ
+}
+func (n *Null) Inspect() string {
+	return "null"
+}
+func (n *Null) String() string {
+	return n.Inspect()
+}
+func (n *Null) Equal(other Object) bool {
+	_, ok := other.(*Null)
+	return ok
+}

object/object.go

@@ -1,14 +1,6 @@
 package object
 
-import (
-	"bytes"
-	"fmt"
-	"hash/fnv"
-	"monkey/ast"
-	"monkey/code"
-	"strings"
-)
-
+// Type represents the type of an object
 type ObjectType string
 
 const (
@@ -39,333 +31,19 @@ type Immutable interface {
 	Clone() Object
 }
 
+// Object represents a value and implementations are expected to implement
+// `Type()` and `Inspect()` functions
 type Object interface {
 	Type() ObjectType
 	String() string
 	Inspect() string
 }
 
-type Integer struct {
-	Value int64
-}
-
-type CompiledFunction struct {
-	Instructions  code.Instructions
-	NumLocals     int
-	NumParameters int
-}
-
-func (i *Integer) Type() ObjectType {
-	return INTEGER_OBJ
-}
-func (i *Integer) Inspect() string {
-	return fmt.Sprintf("%d", i.Value)
-}
-func (i *Integer) Clone() Object {
-	return &Integer{Value: i.Value}
-}
-func (i *Integer) String() string {
-	return i.Inspect()
-}
-func (i *Integer) Equal(other Object) bool {
-	if obj, ok := other.(*Integer); ok {
-		return i.Value == obj.Value
-	}
-	return false
-}
-
-type Boolean struct {
-	Value bool
-}
-
-func (b *Boolean) Type() ObjectType {
-	return BOOLEAN_OBJ
-}
-func (b *Boolean) Inspect() string {
-	return fmt.Sprintf("%t", b.Value)
-}
-func (b *Boolean) Clone() Object {
-	return &Boolean{Value: b.Value}
-}
-func (b *Boolean) String() string {
-	return b.Inspect()
-}
-func (b *Boolean) Equal(other Object) bool {
-	if obj, ok := other.(*Boolean); ok {
-		return b.Value == obj.Value
-	}
-	return false
-}
-
-type Null struct{}
-
-func (n *Null) Type() ObjectType {
-	return NULL_OBJ
-}
-func (n *Null) Inspect() string {
-	return "null"
-}
-func (n *Null) String() string {
-	return n.Inspect()
-}
-func (n *Null) Equal(other Object) bool {
-	_, ok := other.(*Null)
-	return ok
-}
-
-type ReturnValue struct {
-	Value Object
-}
-
-func (rv *ReturnValue) Type() ObjectType {
-	return RETURN_VALUE_OBJ
-}
-func (rv *ReturnValue) Inspect() string {
-	return rv.Value.Inspect()
-}
-func (rv *ReturnValue) String() string {
-	return rv.Inspect()
-}
-
-type Error struct {
-	Message string
-}
-
-func (e *Error) Type() ObjectType {
-	return ERROR_OBJ
-}
-func (e *Error) Inspect() string {
-	return "Error: " + e.Message
-}
-func (e *Error) Clone() Object {
-	return &Error{Message: e.Message}
-}
-func (e *Error) String() string {
-	return e.Message
-}
-
-type Function struct {
-	Parameters []*ast.Identifier
-	Body       *ast.BlockStatement
-	Env        *Environment
-}
-
-func (f *Function) Type() ObjectType {
-	return FUNCTION_OBJ
-}
-func (f *Function) Inspect() string {
-	var out bytes.Buffer
-
-	params := []string{}
-	for _, p := range f.Parameters {
-		params = append(params, p.String())
-	}
-
-	out.WriteString("fn")
-	out.WriteString("(")
-	out.WriteString(strings.Join(params, ", "))
-	out.WriteString(") {\n")
-	out.WriteString(f.Body.String())
-	out.WriteString("\n}")
-
-	return out.String()
-}
-func (f *Function) String() string {
-	return f.Inspect()
-}
-
-type String struct {
-	Value string
-}
-
-func (s *String) Type() ObjectType {
-	return STRING_OBJ
-}
-func (s *String) Inspect() string {
-	return fmt.Sprintf("%#v", s.Value)
-}
-func (s *String) Clone() Object {
-	return &String{Value: s.Value}
-}
-func (s *String) String() string {
-	return s.Value
-}
-func (s *String) Equal(other Object) bool {
-	if obj, ok := other.(*String); ok {
-		return s.Value == obj.Value
-	}
-	return false
-}
-
-type BuiltinFunction func(args ...Object) Object
-
-type Builtin struct {
-	Name string
-	Fn   BuiltinFunction
-}
-
-func (b *Builtin) Type() ObjectType {
-	return BUILTIN_OBJ
-}
-func (b *Builtin) Inspect() string {
-	return fmt.Sprintf("<built-in function %s>", b.Name)
-}
-func (b *Builtin) String() string {
-	return b.Inspect()
-}
-
-type Array struct {
-	Elements []Object
-}
-
-func (ao *Array) Type() ObjectType {
-	return ARRAY_OBJ
-}
-func (ao *Array) Inspect() string {
-	var out bytes.Buffer
-
-	elements := []string{}
-	for _, e := range ao.Elements {
-		elements = append(elements, e.Inspect())
-	}
-
-	out.WriteString("[")
-	out.WriteString(strings.Join(elements, ", "))
-	out.WriteString("]")
-
-	return out.String()
-}
-func (ao *Array) String() string {
-	return ao.Inspect()
-}
-func (ao *Array) Equal(other Object) bool {
-	if obj, ok := other.(*Array); ok {
-		if len(ao.Elements) != len(obj.Elements) {
-			return false
-		}
-		for i, el := range ao.Elements {
-			cmp, ok := el.(Comparable)
-			if !ok {
-				return false
-			}
-			if !cmp.Equal(obj.Elements[i]) {
-				return false
-			}
-		}
-
-		return true
-	}
-	return false
-}
-
-type HashKey struct {
-	Type  ObjectType
-	Value uint64
-}
-
-func (b *Boolean) HashKey() HashKey {
-	var value uint64
-
-	if b.Value {
-		value = 1
-	} else {
-		value = 0
-	}
-
-	return HashKey{Type: b.Type(), Value: value}
-}
-
+// Hashable is the interface for all hashable objects which must implement
+// the HashKey() method which returns a HashKey result.
 type Hashable interface {
 	HashKey() HashKey
 }
 
-func (i *Integer) HashKey() HashKey {
-	return HashKey{Type: i.Type(), Value: uint64(i.Value)}
-}
-
-func (s *String) HashKey() HashKey {
-	h := fnv.New64a()
-	h.Write([]byte(s.Value))
-
-	return HashKey{Type: s.Type(), Value: h.Sum64()}
-}
-
-type HashPair struct {
-	Key   Object
-	Value Object
-}
-
-type Hash struct {
-	Pairs map[HashKey]HashPair
-}
-
-func (h *Hash) Type() ObjectType {
-	return HASH_OBJ
-}
-func (h *Hash) Inspect() string {
-	var out bytes.Buffer
-
-	pairs := []string{}
-	for _, pair := range h.Pairs {
-		pairs = append(pairs, fmt.Sprintf("%s: %s", pair.Key.Inspect(), pair.Value.Inspect()))
-	}
-
-	out.WriteString("{")
-	out.WriteString(strings.Join(pairs, ", "))
-	out.WriteString("}")
-
-	return out.String()
-}
-func (h *Hash) String() string {
-	return h.Inspect()
-}
-func (h *Hash) Equal(other Object) bool {
-	if obj, ok := other.(*Hash); ok {
-		if len(h.Pairs) != len(obj.Pairs) {
-			return false
-		}
-		for _, pair := range h.Pairs {
-			left := pair.Value
-			hashed := left.(Hashable)
-			right, ok := obj.Pairs[hashed.HashKey()]
-			if !ok {
-				return false
-			}
-			cmp, ok := left.(Comparable)
-			if !ok {
-				return false
-			}
-			if !cmp.Equal(right.Value) {
-				return false
-			}
-		}
-
-		return true
-	}
-	return false
-}
-
-func (cf *CompiledFunction) Type() ObjectType {
-	return COMPILED_FUNCTION_OBJ
-}
-func (cf *CompiledFunction) Inspect() string {
-	return fmt.Sprintf("CompiledFunction[%p]", cf)
-}
-func (cf *CompiledFunction) String() string {
-	return cf.Inspect()
-}
-
-type Closure struct {
-	Fn   *CompiledFunction
-	Free []Object
-}
-
-func (c *Closure) Type() ObjectType {
-	return CLOSURE_OBJ
-}
-func (c *Closure) Inspect() string {
-	return fmt.Sprintf("Closure[%p]", c)
-}
-func (c *Closure) String() string {
-	return c.Inspect()
-}
+// BuiltinFunction represents the builtin function type
+type BuiltinFunction func(args ...Object) Object

object/str.go

@@ -0,0 +1,26 @@
+package object
+
+import "fmt"
+
+type String struct {
+	Value string
+}
+
+func (s *String) Type() ObjectType {
+	return STRING_OBJ
+}
+func (s *String) Inspect() string {
+	return fmt.Sprintf("%#v", s.Value)
+}
+func (s *String) Clone() Object {
+	return &String{Value: s.Value}
+}
+func (s *String) String() string {
+	return s.Value
+}
+func (s *String) Equal(other Object) bool {
+	if obj, ok := other.(*String); ok {
+		return s.Value == obj.Value
+	}
+	return false
+}