feat(dict): introduce the usage property

.helix/languages.toml

@@ -0,0 +1,2 @@
+[language-server.rust-analyzer.config]
+cargo.features = ["sqlite"]

NEWS

@@ -1,7 +1,17 @@
 What's New in libchewing (unreleased)
 ---------------------------------------------------------
 
+* Features
+  - dict: loading user dictionary are now also controlled by enabled_dicts
+    in `chewing_new3()`.
+
+* Bug Fixes
+  - dict: fixed parsing trie dictionary file with extension fields.
+
 * Changes
+  - rust: breaking! renamed SystemDictionaryLoader to AssetLoader.
+  - rust: breaking! renamed UserDictionaryLoader to UserDictionaryManager.
+  - rust: Dictionary trait gained a new `set_usage()` method.
   - conversion: adjust max output paths down to 10.
 
 What's New in libchewing 0.11.0 (January 10, 2026)

capi/src/io.rs

@@ -134,7 +134,7 @@ pub unsafe extern "C" fn chewing_new2(
         chewing_new3(
             syspath,
             userpath,
-            c"word.dat,tsi.dat".as_ptr(),
+            c"word.dat,tsi.dat,chewing.dat".as_ptr(),
             logger,
             loggerdata,
         )
@@ -237,7 +237,7 @@ pub unsafe extern "C" fn chewing_new3(
 /// don't need to be freed.
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn chewing_get_defaultDictionaryNames() -> *const c_char {
-    c"word.dat,tsi.dat".as_ptr()
+    c"word.dat,tsi.dat,chewing.dat".as_ptr()
 }
 
 /// Releases the resources used by the given Chewing IM instance.

src/dictionary/layered.rs

@@ -1,12 +1,12 @@
-use std::{
-    collections::{BTreeMap, btree_map::Entry},
-    iter,
-};
+use std::collections::{BTreeMap, btree_map::Entry};
 
 use log::error;
 
 use super::{Dictionary, DictionaryInfo, Entries, LookupStrategy, Phrase, UpdateDictionaryError};
-use crate::zhuyin::Syllable;
+use crate::{
+    dictionary::{DictionaryUsage, TrieBuf},
+    zhuyin::Syllable,
+};
 
 /// A collection of dictionaries that returns the union of the lookup results.
 /// # Examples
@@ -29,7 +29,7 @@ use crate::zhuyin::Syllable;
 ///     vec![("策", 100), ("冊", 100)]
 /// )]);
 ///
-/// let dict = Layered::new(vec![Box::new(sys_dict)], Box::new(user_dict));
+/// let dict = Layered::new(vec![Box::new(sys_dict), Box::new(user_dict)]);
 /// assert_eq!(
 ///     [
 ///         ("側", 1, 0).into(),
@@ -48,20 +48,31 @@ use crate::zhuyin::Syllable;
 /// ```
 #[derive(Debug)]
 pub struct Layered {
-    sys_dict: Vec<Box<dyn Dictionary>>,
-    user_dict: Box<dyn Dictionary>,
+    dicts: Vec<Box<dyn Dictionary>>,
+    user_dict_index: usize,
 }
 
 impl Layered {
     /// Creates a new `Layered` with the list of dictionaries.
-    pub fn new(sys_dict: Vec<Box<dyn Dictionary>>, user_dict: Box<dyn Dictionary>) -> Layered {
+    pub fn new(mut dicts: Vec<Box<dyn Dictionary>>) -> Layered {
+        let user_dict_index = dicts.iter().enumerate().find_map(|d| {
+            if d.1.about().usage == DictionaryUsage::User {
+                Some(d.0)
+            } else {
+                None
+            }
+        });
+        if user_dict_index.is_none() {
+            dicts.push(Box::new(TrieBuf::new_in_memory()));
+        }
+        let user_dict_index = user_dict_index.unwrap_or(dicts.len() - 1);
         Layered {
-            sys_dict,
-            user_dict,
+            dicts,
+            user_dict_index,
         }
     }
     pub fn user_dict(&mut self) -> &mut dyn Dictionary {
-        self.user_dict.as_mut()
+        self.dicts[self.user_dict_index].as_mut()
     }
 }
 
@@ -89,44 +100,36 @@ impl Dictionary for Layered {
         let mut sort_map: BTreeMap<String, usize> = BTreeMap::new();
         let mut phrases: Vec<Phrase> = Vec::new();
 
-        self.sys_dict
-            .iter()
-            .chain(iter::once(&self.user_dict))
-            .for_each(|d| {
-                for phrase in d.lookup(syllables, strategy) {
-                    debug_assert!(!phrase.as_str().is_empty());
-                    match sort_map.entry(phrase.to_string()) {
-                        Entry::Occupied(entry) => {
-                            let index = *entry.get();
-                            phrases[index].freq += phrase.freq;
-                            phrases[index].last_used =
-                                match (phrases[index].last_used, phrase.last_used) {
-                                    (Some(orig), Some(new)) => Some(u64::max(orig, new)),
-                                    (Some(orig), None) => Some(orig),
-                                    (None, Some(new)) => Some(new),
-                                    (None, None) => None,
-                                };
-                        }
-                        Entry::Vacant(entry) => {
-                            entry.insert(phrases.len());
-                            phrases.push(phrase);
-                        }
+        self.dicts.iter().for_each(|d| {
+            for phrase in d.lookup(syllables, strategy) {
+                debug_assert!(!phrase.as_str().is_empty());
+                match sort_map.entry(phrase.to_string()) {
+                    Entry::Occupied(entry) => {
+                        let index = *entry.get();
+                        phrases[index].freq += phrase.freq;
+                        phrases[index].last_used =
+                            match (phrases[index].last_used, phrase.last_used) {
+                                (Some(orig), Some(new)) => Some(u64::max(orig, new)),
+                                (Some(orig), None) => Some(orig),
+                                (None, Some(new)) => Some(new),
+                                (None, None) => None,
+                            };
+                    }
+                    Entry::Vacant(entry) => {
+                        entry.insert(phrases.len());
+                        phrases.push(phrase);
                     }
                 }
-            });
+            }
+        });
         phrases
     }
 
     /// Returns all entries from all dictionaries.
     ///
     /// **NOTE**: Duplicate entries are not removed.
     fn entries(&self) -> Entries<'_> {
-        Box::new(
-            self.sys_dict
-                .iter()
-                .chain(iter::once(&self.user_dict))
-                .flat_map(|dict| dict.entries()),
-        )
+        Box::new(self.dicts.iter().flat_map(|dict| dict.entries()))
     }
 
     fn about(&self) -> DictionaryInfo {
@@ -140,12 +143,14 @@ impl Dictionary for Layered {
         None
     }
 
+    fn set_usage(&mut self, _usage: DictionaryUsage) {}
+
     fn reopen(&mut self) -> Result<(), UpdateDictionaryError> {
-        self.user_dict.reopen()
+        self.user_dict().reopen()
     }
 
     fn flush(&mut self) -> Result<(), UpdateDictionaryError> {
-        self.user_dict.flush()
+        self.user_dict().flush()
     }
 
     fn add_phrase(
@@ -157,7 +162,7 @@ impl Dictionary for Layered {
             error!("BUG! added phrase is empty");
             return Ok(());
         }
-        self.user_dict.add_phrase(syllables, phrase)
+        self.user_dict().add_phrase(syllables, phrase)
     }
 
     fn update_phrase(
@@ -171,7 +176,7 @@ impl Dictionary for Layered {
             error!("BUG! added phrase is empty");
             return Ok(());
         }
-        self.user_dict
+        self.user_dict()
             .update_phrase(syllables, phrase, user_freq, time)
     }
 
@@ -180,7 +185,8 @@ impl Dictionary for Layered {
         syllables: &[Syllable],
         phrase_str: &str,
     ) -> Result<(), UpdateDictionaryError> {
-        self.user_dict.remove_phrase(syllables, phrase_str)
+        // TODO use exclude list
+        self.user_dict().remove_phrase(syllables, phrase_str)
     }
 }
 
@@ -194,7 +200,8 @@ mod tests {
     use super::Layered;
     use crate::{
         dictionary::{
-            Dictionary, DictionaryBuilder, LookupStrategy, Phrase, Trie, TrieBuf, TrieBuilder,
+            Dictionary, DictionaryBuilder, DictionaryUsage, LookupStrategy, Phrase, Trie, TrieBuf,
+            TrieBuilder,
         },
         syl,
         zhuyin::Bopomofo,
@@ -211,7 +218,7 @@ mod tests {
             vec![("策", 100), ("冊", 100)],
         )]);
 
-        let dict = Layered::new(vec![Box::new(sys_dict)], Box::new(user_dict));
+        let dict = Layered::new(vec![Box::new(sys_dict), Box::new(user_dict)]);
         assert_eq!(
             [
                 (
@@ -253,7 +260,7 @@ mod tests {
             vec![("策", 100), ("冊", 100)],
         )]);
 
-        let dict = Layered::new(vec![Box::new(sys_dict)], Box::new(user_dict));
+        let dict = Layered::new(vec![Box::new(sys_dict), Box::new(user_dict)]);
         assert_eq!(
             Some(("側", 1, 0).into()),
             dict.lookup(
@@ -287,6 +294,7 @@ mod tests {
             vec![("測", 1), ("冊", 1), ("側", 1)],
         )]);
         let mut builder = TrieBuilder::new();
+        builder.set_usage(DictionaryUsage::User);
         builder.insert(
             &[syl![Bopomofo::C, Bopomofo::E, Bopomofo::TONE4]],
             ("策", 100, 0).into(),
@@ -298,9 +306,10 @@ mod tests {
         let mut cursor = Cursor::new(vec![]);
         builder.write(&mut cursor)?;
         cursor.rewind()?;
-        let user_dict = Trie::new(&mut cursor)?;
+        let mut user_dict = Trie::new(&mut cursor)?;
+        user_dict.set_usage(DictionaryUsage::User);
 
-        let mut dict = Layered::new(vec![Box::new(sys_dict)], Box::new(user_dict));
+        let mut dict = Layered::new(vec![Box::new(sys_dict), Box::new(user_dict)]);
         assert_eq!(
             Some(("側", 1, 0).into()),
             dict.lookup(