feat: hashtag list and quick filter override

README.md

@@ -110,8 +110,9 @@ Dots can be repeated to move to parent tasks.
 
 Property Filters:
 
-- `+TAG` - filter by tag
+- `#TAG` - set tag filter (empty: list all used tags)
-- `-TAG` - remove filter by tag
+- `+TAG` - add tag filter
+- `-TAG` - remove tag filters
 - `?STATE` - filter by state (type or description) - plain `?` to reset
 
 State descriptions can be used for example for Kanban columns or review flows.

src/kinds.rs

@@ -58,6 +58,6 @@ fn format_tag(tag: &Tag) -> String {
 
 pub(crate) fn is_hashtag(tag: &Tag) -> bool {
     tag.single_letter_tag()
-        .is_some_and(|sltag| sltag.character == Alphabet::T)
+        .is_some_and(|letter| letter.character == Alphabet::T)
 }
 

src/main.rs

@@ -331,7 +331,17 @@ async fn main() {
                         }
                     },
 
-                    Some('#') | Some('+') => {
+                    Some('#') => {
+                        match arg {
+                            Some(arg) => tasks.set_tag(arg.to_string()),
+                            None => {
+                                println!("Hashtags of all known tasks:\n{}", tasks.all_hashtags().join(" "));
+                                continue
+                            }
+                        }
+                    }
+
+                    Some('+') => {
                         match arg {
                             Some(arg) => tasks.add_tag(arg.to_string()),
                             None => tasks.clear_filter()

src/tasks.rs

@@ -102,6 +102,16 @@ impl Tasks {
 
         children
     }
+    
+    pub(crate) fn all_hashtags(&self) -> impl Iterator<Item=&str> {
+        self.tasks.values()
+            .filter(|t| t.pure_state() != State::Closed)
+            .filter_map(|t| t.tags.as_ref()).flatten()
+            .filter(|tag| is_hashtag(tag))
+            .filter_map(|tag| tag.content().map(|s| s.trim()))
+            .sorted_unstable()
+            .dedup()
+    }
 
     /// Total time in seconds tracked on this task by the current user.
     pub(crate) fn time_tracked(&self, id: EventId) -> u64 {
@@ -350,6 +360,11 @@ impl Tasks {
         info!("Removed all filters");
     }
 
+    pub(crate) fn set_tag(&mut self, tag: String) {
+        self.tags.clear();
+        self.add_tag(tag);
+    }
+
     pub(crate) fn add_tag(&mut self, tag: String) {
         self.view.clear();
         info!("Added tag filter for #{tag}");