package main

import (
	"bytes"
	"io"
)

type Splitter struct {
	Delimiter []byte
	IgnoreEOF bool
}

func (that *Splitter) Split(data []byte, atEOF bool) (int, []byte, error) {
	for i := 0; i < len(data); i++ {
		if bytes.Equal(data[i:i+len(that.Delimiter)], that.Delimiter) {
			return i + len(that.Delimiter), data[:i], nil
		}
	}
	if len(data) == 0 || !atEOF {
		return 0, nil, nil
	}
	if atEOF && that.IgnoreEOF {
		return len(data), data, nil
	}
	return 0, data, io.ErrUnexpectedEOF
}