Stack.go

package main

import "fmt"

func main () {
	fmt.Println("-= Stack Demo  =-")
	s := Stack()
	s.Push(Int, 0)
	s.Push(Int, 1)
	s.Push(Int, 2)
	s.Push(Float, 3)
	s.Push(String, "f")
	s.Push(Int, 5)
	fmt.Println(s.String())
	fmt.Println("-= End of Demo =-")
}

type RTType int
const (
	None	RTType = iota

	Byte
	Char
	Int
	UInt
	Float
	String
	Array
)

type RTArray struct {
	size	uint64
	data	[]RTObject
}

type RTObject struct {
	t	RTType
	val	interface{}
}

type RTStackElement struct {
	val	RTObject
	next	*RTStackElement
}

type RTStack struct {
	top	*RTStackElement
	size	uint64
}

func Stack() (s RTStack) {
	s = RTStack{
		top:	nil,
		size:	0,
	}
	return
}

func (s *RTStack) Len () uint64 {
	return s.size
}

func (s *RTStack) Peek () *RTObject {
	return s.top.val
}

func (s *RTStack) String () (str string) {
	str = fmt.Sprintf("Stack [%#v", s.top.val.val)
	p := s.top.next
	for p != nil {
		str = fmt.Sprintf("%s, %#v", str, p.v)
		p = p.next
	}
	str += "]"
	return
}

func (s *RTStack) Pop () (v *RTObject) {
	if s.size > 0 {
		v, s.top = s.top, s.top.next
		s.size--
		return
	}
	return nil
}

func (s *RTStack) Push (t RTType, o interface{}) {
	s.top = &RTObject{
		v:	o,
		t:	t,
		next:	s.top,
	}
	s.size++
}