golang: Split things into packages

This makes this logically more separate! :) As an aside...

I really hate the way golang does dependencies and packages. Yes, some
people insist on nesting their code deep into a $GOPATH, which is fine
if you're a google dev and are forced to work this way, but annoying for
the rest of the world. Your code shouldn't need a git commit to switch
to a a different vcs host! Gah I hate this so much.

event/event.go

@@ -0,0 +1,117 @@
+// Mgmt
+// Copyright (C) 2013-2016+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// Package event provides some primitives that are used for message passing.
+package event
+
+import (
+	"fmt"
+)
+
+//go:generate stringer -type=EventName -output=eventname_stringer.go
+type EventName int
+
+const (
+	EventNil EventName = iota
+	EventExit
+	EventStart
+	EventPause
+	EventPoke
+	EventBackPoke
+)
+
+// Resp is a channel to be used for boolean responses. A nil represents an ACK,
+// and a non-nil represents a NACK (false). This also lets us use custom errors.
+type Resp chan error
+
+// Event is the main struct that stores event information and responses.
+type Event struct {
+	Name EventName
+	Resp Resp // channel to send an ack response on, nil to skip
+	//Wg   *sync.WaitGroup // receiver barrier to Wait() for everyone else on
+	Msg      string // some words for fun
+	Activity bool   // did something interesting happen?
+}
+
+// ACK sends a single acknowledgement on the channel if one was requested.
+func (event *Event) ACK() {
+	if event.Resp != nil { // if they've requested an ACK
+		event.Resp.ACK()
+	}
+}
+
+// NACK sends a negative acknowledgement message on the channel if one was requested.
+func (event *Event) NACK() {
+	if event.Resp != nil { // if they've requested a NACK
+		event.Resp.NACK()
+	}
+}
+
+// ACKNACK sends a custom ACK or NACK message on the channel if one was requested.
+func (event *Event) ACKNACK(err error) {
+	if event.Resp != nil { // if they've requested a NACK
+		event.Resp.ACKNACK(err)
+	}
+}
+
+// NewResp is just a helper to return the right type of response channel.
+func NewResp() Resp {
+	resp := make(chan error)
+	return resp
+}
+
+// ACK sends a true value to resp.
+func (resp Resp) ACK() {
+	if resp != nil {
+		resp <- nil
+	}
+}
+
+// NACK sends a false value to resp.
+func (resp Resp) NACK() {
+	if resp != nil {
+		resp <- fmt.Errorf("NACK")
+	}
+}
+
+// ACKNACK sends a custom ACK or NACK. The ACK value is always nil, the NACK can
+// be any non-nil error value.
+func (resp Resp) ACKNACK(err error) {
+	if resp != nil {
+		resp <- err
+	}
+}
+
+// Wait waits for any response from a Resp channel and returns it.
+func (resp Resp) Wait() error {
+	return <-resp
+}
+
+// ACKWait waits for a +ive Ack from a Resp channel.
+func (resp Resp) ACKWait() {
+	for {
+		// wait until true value
+		if resp.Wait() == nil {
+			return
+		}
+	}
+}
+
+// GetActivity returns the activity value.
+func (event *Event) GetActivity() bool {
+	return event.Activity
+}