// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//

package pipe

// YieldFunc yields a record from an Iterator to up-stream (Consumer).
type YieldFunc = func(Record) error

// Iterator yields a record.
type Iterator interface {
	Each(YieldFunc) error
}

// Consumer consumes records from an iterator.
type Consumer interface {
	Consume(Iterator) error
}

// Transform represents both a record consumer and producer.
// It has an input and output.
// It takes a single record and provides an iterator for all the records.
type Transform interface {
	Iterator // producer: should never return on yield().err == nil
	Consumer
}