Monkey/object/object.go

package object

import "fmt"

// ObjType type of object
type ObjType string

const (
	IntegerObj     = "INTEGER"
	BooleanObj     = "BOOLEAN"
	NullObj        = "NULL"
	ReturnValueObj = "RETURN_VALUE"
	ErrorObj       = "ERROR"
)

// Object source code as an Object
type Object interface {
	Type() ObjType
	Inspect() string
}

type Integer struct {
	Value int64
}

func (i *Integer) Type() ObjType   { return IntegerObj }
func (i *Integer) Inspect() string { return fmt.Sprintf("%d", i.Value) }

type Boolean struct {
	Value bool
}

func (b *Boolean) Type() ObjType   { return BooleanObj }
func (b *Boolean) Inspect() string { return fmt.Sprintf("%t", b.Value) }

type Null struct{}

func (n *Null) Type() ObjType   { return NullObj }
func (n *Null) Inspect() string { return "null" }

type ReturnValue struct {
	Value Object
}

func (rv *ReturnValue) Type() ObjType   { return ReturnValueObj }
func (rv *ReturnValue) Inspect() string { return rv.Value.Inspect() }

type Error struct {
	Msg string
}

func (e *Error) Type() ObjType   { return ErrorObj }
func (e *Error) Inspect() string { return "ERROR: " + e.Msg }