added comments for worker pool

workerpool/main.go

@@ -8,15 +8,25 @@ import (
 	"github.com/labstack/gommon/log"
 )
 
+// Task encapsulates a work item that should go in a work
+// pool.
 type Task struct {
+	// Err holds an error that occurred during a task. Its
+	// result is only meaningful after Run has been called
+	// for the pool that holds it.
 	Err error
+
 	f func() error
 }
 
+// NewTask initializes a new task based on a given work
+// function.
 func NewTask(f func() error) *Task {
 	return &Task{f: f}
 }
 
+// Run runs a Task and does appropriate accounting via a
+// given sync.WorkGroup.
 func (t *Task) Run(wg *sync.WaitGroup) {
 	t.Err = t.f()
 	wg.Done()