todoman is command-line utility to operate with VTODO (tasks) in vdir format. So its task lists can be synchronized with caldav server and then used with android tasks.org app.

But tasks.org suppots subtasks, and todoman does not.

Subtasks are very useful for planning complex activities.

In rfc 5545 subtasks are VEVENT objecs with field RELATED-TO with REL-TYPE=PARENT, which references other VEVENT.

Following changes are needed to support subtasks in todoman

new subcommand

Add --subtask-of command line option which would receive task ID.

Show subcommand

Show pearent task before current task if task has parent.

list subcomand

Change sort order so subtask would always appear direcrly after parent task. Display subtask with indent.

edit subcommand

Add option to change/add/remove parent task

delete

Should be able to remove all subtasks at once when parent task is removed. But also should be possible to remove just parent task and convert all subtasks of it to toplevel tasks

copy, move

When subtask operation requested, should ask twice. When parent task operation is requested, should ask whether to take all subtasks with parent.