Paginator in Golang

paginator.go

package main

import (
	"math"
	"fmt"
)

type (
	
	Data struct {
		X int
	}
	
	Paginator struct {
		Content []interface{}
		PerPage int
	}
	
	Page struct {
		PageNum int
		StartIdx int
		EndIdx int
		Content []interface{}
		HasNext bool
		HasPrevious bool
		
		TotalPages int
		PerPage int
	}
)

func (p Paginator) GetPage(page_num int) Page {
	per_page := p.PerPage
	total := len(p.Content)
	total_pages := int(math.Ceil(float64(total) / float64(p.PerPage)))

	fmt.Println(per_page)
	fmt.Println(page_num)
	fmt.Println(total_pages)
	fmt.Println(total)
	
	page := Page{}

	paged_list := make([]interface{}, per_page)
	if page_num < total_pages {
		if per_page*(page_num+1) <= total {
			paged_list = p.Content[per_page*page_num : per_page*(page_num+1)]
			page = Page{page_num, per_page*page_num, per_page*(page_num+1) - 1, paged_list, true, page_num != 0, total_pages, per_page}
		} else {
			paged_list = p.Content[per_page*page_num:]
			page = Page{page_num, per_page*page_num, total - 1, paged_list, false, page_num != 0, total_pages, per_page}
		}
	}
	
	return page
}

func main() {
	dlist := make([]Data, 0)
	for i := 0; i < 40; i++ {
		d := Data{i}
		dlist = append(dlist, d)
	}
	
	b := make([]interface{}, len(dlist))
	for i := range dlist {
    		b[i] = dlist[i]
	}
	p := Paginator{b, 5}
	c := p.GetPage(1)
	fmt.Println(c)
	
	e := make([]Data, len(c.Content))
	for i := range c.Content {
    		e[i] = c.Content[i].(Data)
	}
	fmt.Println(e)
}