selsl/selsl/value/value.go

package value

import "fmt"

type Members map[string]Value

type Value interface {
	Name() string
	// Proto/type of the value.
	Type() Type
	String() string
	Members() Members
}

// A type is also a value
type Type Value

var TypeType Type = NewObject("Type", nil, nil)
var ObjectType Type = NewObject("Object", TypeType, nil)
var ErrorType Type = NewObject("Error", ObjectType, nil)
var StringType Type = NewObject("String", ObjectType, nil)
var IntType Type = NewObject("Int", ObjectType, nil)
var ListType Type = NewObject("List", ObjectType, nil)
var MethodType Type = NewObject("Method", ObjectType, nil)

type Object struct {
	name    string
	typ     Type
	members Members
}

func (o Object) String() string {
	return fmt.Sprintf("%s: %d", o.typ, o.name)
}

func (o Object) Name() string {
	return o.name
}

func (o Object) Members() Members {
	return o.members
}

func (o Object) Type() Type {
	return o.typ
}

func NewObject(name string, typ Type, members Members) Object {
	return Object{name: name, typ: typ, members: members}
}

type Error struct {
	Object
	Value error
}

func (s Error) String() string {
	return fmt.Sprintf("%w", s.Value)
}

func NewError(name string, members Members, value error) Error {
	return Error{Object: NewObject(name, ErrorType, members),
		Value: value}
}

type String struct {
	Object
	Value string
}

func (s String) String() string {
	return s.Value
}

func NewString(name string, members Members, value string) String {
	return String{Object: NewObject(name, StringType, members),
		Value: value}
}

type Int struct {
	Object
	Value int64
}

func NewInt(name string, members Members, value int64) Int {
	return Int{Object: NewObject(name, IntType, members),
		Value: value}
}

func (i Int) String() string {
	return fmt.Sprintf("%d", i.Value)
}

type List struct {
	Object
	Value []Value
}

func NewList(name string, members Members, value ...Value) List {
	return List{Object: NewObject(name, ListType, members),
		Value: value}
}

func (l List) String() string {
	return fmt.Sprintf("[%v]", l.Value)
}

type Method struct {
	Object
	Value func(env Value, self Value, args ...Value) List
}

func NewMethod(name string, members Members,
	value func(env Value, self Value, args ...Value) List) Method {
	return Method{Object: NewObject(name, MethodType, members),
		Value: value}
}

func (m Method) String() string {
	return fmt.Sprintf("Method: %s", m.Name)
}

var _ Value = String{}
var _ Value = Int{}
var _ Value = List{}