sketch of journal engine API

api.go

package tjournal

import (
	"fmt"
)

// XXX get this from pitbase
type Addr string

// type Input fmt.Stringer
// type Output fmt.Stringer
// these are better; O(1) performance
type Input Addr
type Output Addr

type Statement fmt.Stringer

type Generator interface {
	Generate(Input, Journal, Checkpoint) (Statement, error)
}

type Tester interface {
	Test(Journal, Journal) (Checkpoint, error)
}

type Publisher interface {
	Publish(Journal, Checkpoint) error
}

// XXX shouldn't these be Journaler and Checkpointer, so that we can
// plug in pitbase or any other db?
type Journal interface {
	// XXX
}

type Checkpoint interface {
	// XXX
}

// XXX do we need a State interface type, or is that just the
// Checkpoint?

// XXX think through recursion/mutex -- see https://bit.ly/3ioWZYl