parsing of todo, retaining state over multiple sessions.

lib/types/tasks.dart

@@ -0,0 +1,32 @@
+class Task {
+  final bool done;
+  final DateTime? begin;
+  final DateTime? end;
+  final String title;
+  final List<String> contexts;
+  final List<String> projects;
+  final Map<String,String> meta;
+  final String? priority;
+
+  Task({
+    required this.title,
+    this.done = false,
+    this.contexts = const [],
+    this.projects = const [],
+    this.meta = const {},
+    this.priority,
+    this.begin,
+    this.end,
+  });
+
+  @override
+  String toString() {
+    return (done ? "x " : "")
+         + (priority == null ? "" : "(${priority!}) ")
+         + (begin == null ? "" : "${begin!.year}-${begin!.month}-${begin!.day} ")
+         + (end == null ? "" : "${end!.year}-${end!.month}-${end!.day} ")
+         + ("$title ")
+         + meta.entries.map((entry) => "${entry.key}:${entry.value}").join(" ")
+    ;
+  }
+}