diff --git a/task.go b/task.go
index 07c5159..c76fa56 100644
--- a/task.go
+++ b/task.go
@@ -48,7 +48,8 @@ type Task struct {
 // Contexts, Projects, Tags
 //
 // For example:
-//  "(A) 2013-07-23 Call Dad @Home @Phone +Family due:2013-07-31 customTag1:Important!"
+//
+//	"(A) 2013-07-23 Call Dad @Home @Phone +Family due:2013-07-31 customTag1:Important!"
 func (task Task) String() string {
 	var text string
 
@@ -270,3 +271,21 @@ func (task *Task) Due() time.Duration {
 	}
 	return task.DueDate.Sub(time.Now())
 }
+
+func (task *Task) HasContext(ctx string) bool {
+	for _, c := range task.Contexts {
+		if c == ctx {
+			return true
+		}
+	}
+	return false
+}
+
+func (task *Task) HasProject(proj string) bool {
+	for _, p := range task.Projects {
+		if p == proj {
+			return true
+		}
+	}
+	return false
+}
diff --git a/todotxt.go b/todotxt.go
index 293e14b..122aff4 100644
--- a/todotxt.go
+++ b/todotxt.go
@@ -183,6 +183,19 @@ func (tasklist *TaskList) WriteToFilename(filename string) error {
 	return ioutil.WriteFile(filename, []byte(tasklist.String()), 0640)
 }
 
+func (tasklist *TaskList) ArchiveTaskToFile(task Task, filename string) error {
+	if err := tasklist.RemoveTask(task); err != nil {
+		return err
+	}
+	f, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, 0600)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.WriteString(task.String() + "\n")
+	return err
+}
+
 // LoadFromFile loads and returns a TaskList from *os.File.
 //
 // Using *os.File instead of a filename allows to also use os.Stdin.