Module tasks 

Tasks: to-dos (VTODO, RFC 5545 §3.6.2) in CalDAV task lists, one per file, with what ties them to the rest (RFC 9253, “iCalendar Relationships”):

• a step of a bigger task: RELATED-TO;RELTYPE=PARENT:<uid>, in the step;
• waits for another: RELATED-TO;RELTYPE=DEPENDS-ON:<uid>, in the one that waits, as Sioul writes it. RFC 9253 §4 puts its temporal links in the one that comes first instead (RELATED-TO;RELTYPE=FINISHTOSTART;GAP=P14D:<uid> for “two weeks after”): read too, and written when there is a gap;
• its notes, mail, drafts, events: LINK (RFC 9253 §8.2): mid: for a message (RFC 2392), sioul: for the rest (links);
• the people and offices it involves: CONTACT, its ALTREP pointing at their card;
• its project: REFID (docs/notes-folder.md);
• how long it takes: ESTIMATED-DURATION (draft-ietf-calext-ical-tasks).

DTSTART says from when a task can start, DUE the date asked from outside. Neither turns into “overdue”: the plan always starts from today (plan, docs/tasks.md).

Tasks are changed line by line (lines): what Sioul does not edit (alarms, another application’s fields) is kept exactly, and a form saved unchanged writes nothing.

Structs

Changed 🔒

What the form changed, field by field.

ContactRef

Someone a task involves (CONTACT, RFC 5545 §3.8.4.2): a name, and where their card is.

Link

Something a task points at (LINK, RFC 9253 §8.2).

Relation

How a task is tied to another component (RELATED-TO, RFC 9253 §9.1).

Task

One task, as read from its file.

TaskEdit

What the task form gives back, and what a task is as the form shows it.

Enums

Status

A task’s state (RFC 5545 §3.8.1.11).

Constants

AT

A time given to a task for one day by a drag in the day view (Task::at), in UTC, as Sioul wrote it before time blocks: read still, never written (a task is pinned to a time by a block, an event every calendar shows, blocks). Not DTSTART: RFC 5545 wants DUE of DTSTART’s value type and after it, and CalDAV servers that check (Sabre: Nextcloud) refuse a task whose start has a time while its date asked is a date, or has passed.

ESTIMATE_FIRST

The first estimate a task was given, written once (Task::estimate_first).

FELT_KEPT

The felt ratings kept in a task’s file: the newest five days.

KINDS

The kinds of task, by what doing them takes: a call, writing, a form or anything done on a website, going out, reading, thinking, making. Tasks of one kind are easier done together.

KIND_CONCEPT

A task’s kind is written as a concept (RFC 9253, CONCEPT), under this tag (RFC 4151): servers and other applications keep it as it is.

OFFICE_CONCEPT

A task that can only be done while offices are open (a call to an office, a counter).

STAMPS 🔒

Lines rewritten at every change (RFC 5545 §3.8.7).

Functions

add_lines

The main VTODO with added lines, those not there yet; the text as it was when all are.

all

Every task of every list.

apply

The task’s text with the form’s changes: only the lines of what changed are written again; nothing changed, nothing is written.

completed_at

A task done at another time than now (an import of what was done before): its COMPLETED line set to at; the text as it was when it already says so.

contact 🔒

contact_line

CONTACT;ALTREP="<uri>":<name>.

date_line 🔒

A DTSTART or DUE line: a date as a DATE, a time in UTC.

day_of 🔒

default_list

Where a new task goes: a writable list made for tasks, then one that also takes them, then one that does not say.

duration_of

Minutes as an iCalendar duration: 15 → “PT15M”, 90 → “PT1H30M”, 20160 → “P14D”.

energy_of

“LIGHT”, “heavy”, “Rest” → “light”, “heavy”, “rest”; anything else, the usual: “”.

field_lines 🔒

The lines of the fields that changed, as the form has them.

is_kind_id

Whether a word can name a kind: lowercase letters, digits and hyphens, as Sioul’s own kinds and those you add (“errand”, “rendez-vous”).

kind_of_concept 🔒

The kind a concept names, when it is one of Sioul’s.

link_line

LINK;LINKREL=…;LABEL=…;VALUE=URI:<uri>, or VALUE=UID for uid:<uid>.

link_of

A LINK line, read.

lists

The calendars that hold tasks.

master_range 🔒

The main VTODO, BEGIN to END: not a changed occurrence (RECURRENCE-ID).

minutes_of

An iCalendar duration in minutes (RFC 5545 §3.3.6): “PT15M” → 15, “P1DT2H” → 1560, “-P1W” → −10080. None when it is not one.

moment 🔒

A DTSTART or DUE line in your time zone: “2026-10-30” for a date, “2026-10-30T17:00” for a time.

new_path

The file a new task gets in a list.

new_task

A new task, with its own UID.

next_turn 🔒

A repeating task’s dates at their next turn after today, the distance between them kept; one without dates waits one turn from today.

one_line 🔒

A value written as it is (a UID, an address): without line breaks or other control characters, which would end its line and start another (an address decoded from %0D%0A, a key from an imported file).

own_lines 🔒

The positions of the main VTODO’s own lines: not its alarms’.

read

One task from its file; None when the file holds an event.

relation_line

RELATED-TO;RELTYPE=<kind>[;GAP=…]:<uid>.

relation_of

A RELATED-TO line, read.

remove_lines

The main VTODO without the lines drop picks; the text as it was when none is.

repeat_of 🔒

“FREQ=WEEKLY;INTERVAL=2” → “weekly”; a rule without one of the four frequencies → “”.

replace_lines

The main VTODO’s lines that drop takes replaced by added, in one change: the stamps written once.

rewrite 🔒

The task’s text with the main VTODO’s lines that keep refuses dropped and added put in, before its alarms; the stamps written again. Nothing dropped and nothing added: the text as it was.

set_felt

How it went, said after the task on on: that day’s rating replaced (a rating with nothing said takes it away), the newest FELT_KEPT days kept, everything else left as it is.

set_gap

A wait with its gap, written in the task that comes first (text), as RFC 9253 §4 places temporal links: RELATED-TO;RELTYPE=FINISHTOSTART;GAP=P14D:<successor> (“the answer comes within two weeks”; no GAP for 0), any other FINISHTOSTART or NEXT to the same task replaced. sioul tasks import and the window’s form of a wait write it so; the text as it was when it says so already.

set_status

The task marked done, started, open again or dropped. A repeating task done comes back instead, its dates moved to their next turn after today.

split_list 🔒

A comma-separated text list (CATEGORIES), its escaped commas kept inside.

status_lines 🔒

The status lines: STATUS, and COMPLETED with PERCENT-COMPLETE when done.

task_of_text

A task from the text of its file, its dates in zone; None when it holds no task.

utc 🔒

zoned 🔒

A DATE-TIME line in zone: UTC, with its TZID, or floating (taken in zone).