Collection of related objects from a single source about irelate HOT 6 CLOSED

package main

import (
	"fmt"
	"io"
	"log"

	"github.com/brentp/irelate"
	"github.com/brentp/irelate/interfaces"
)

func check(e error) {
	if e != nil {
		log.Fatal(e)
	}
}

type ri struct {
	i               int
	interval_starts []int
}

type interval struct {
	start   int
	related []interfaces.Relatable
}

func (r *ri) Next() (interfaces.Relatable, error) {
	if r.i == len(r.interval_starts) {
		return nil, io.EOF
	}
	result := &interval{start: r.interval_starts[r.i]}
	r.i++
	return result, nil
}

func (r *ri) Close() error {
	return nil
}

func (i *interval) Chrom() string {
	return "chr1"
}
func (i *interval) Start() uint32 {
	return uint32(i.start)
}
func (i *interval) End() uint32 {
	return uint32(i.start + 20)
}

func (i *interval) Related() []interfaces.Relatable {
	return i.related
}

func (i *interval) AddRelated(r interfaces.Relatable) {
	i.related = append(i.related, r)
}

func (i *interval) Source() uint32 {
	return 0
}
func (i *interval) SetSource(u uint32) {
}

func main() {
	rels := &ri{i: 0, interval_starts: []int{0, 5, 10, 15, 20, 25, 110, 115}}

	it := irelate.IRelate(irelate.CheckRelatedByOverlap, irelate.SelfRelations, irelate.Less, rels)
	for {
		interval, err := it.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			panic(err)
		}
		fmt.Printf("%s\t%d\t%d\t%d\n", interval.Chrom(), interval.Start(), interval.End(), len(interval.Related()))
	}
}