refactor!: remove SyllableSlice trait

Author: kanru

NEWS

@@ -15,6 +15,7 @@ What's New in libchewing (unreleased)
     used to initialize a chewing context with specific dictionaries enabled.
   - New boolean config option `chewing.sort_candidates_by_frequency` can be
     set to enable sorting candidates by frequency.
+  - Rust type SyllableSlice is removed from public interfaces.
 
 * Bug Fixes
   - Auto shift cursor after candidate selection now moves the cursor to the

src/conversion/chewing.rs

@@ -6,7 +6,10 @@ use std::{
 
 use log::trace;
 
-use crate::dictionary::{Dictionary, LookupStrategy, Phrase};
+use crate::{
+    dictionary::{Dictionary, LookupStrategy, Phrase},
+    zhuyin::Syllable,
+};
 
 use super::{Composition, ConversionEngine, Gap, Interval, Symbol};
 
@@ -149,9 +152,14 @@ impl ChewingEngine {
             return None;
         }
 
+        let syllables: Vec<Syllable> = symbols
+            .iter()
+            .map(|s| s.to_syllable().unwrap_or_default())
+            .collect();
+
         let mut max_freq = 0;
         let mut best_phrase = None;
-        'next_phrase: for phrase in dict.lookup_all_phrases(&symbols, self.lookup_strategy) {
+        'next_phrase: for phrase in dict.lookup_all_phrases(&syllables, self.lookup_strategy) {
             // If there exists a user selected interval which is a
             // sub-interval of this phrase but the substring is
             // different then we can skip this phrase.

src/conversion/mod.rs

@@ -6,15 +6,11 @@ mod simple;
 mod symbol;
 
 use std::{
-    borrow::Cow,
     cmp::{max, min},
     fmt::Debug,
 };
 
-use crate::{
-    dictionary::Dictionary,
-    zhuyin::{Syllable, SyllableSlice},
-};
+use crate::{dictionary::Dictionary, zhuyin::Syllable};
 
 pub use self::chewing::ChewingEngine;
 pub use self::fuzzy::FuzzyChewingEngine;
@@ -150,30 +146,6 @@ impl From<char> for Symbol {
     }
 }
 
-impl SyllableSlice for &[Symbol] {
-    fn to_slice(&self) -> Cow<'static, [Syllable]> {
-        self.iter()
-            .map_while(|&sym| match sym {
-                Symbol::Syllable(syl) => Some(syl),
-                Symbol::Char(_) => None,
-            })
-            .collect::<Vec<_>>()
-            .into()
-    }
-}
-
-impl SyllableSlice for Vec<Symbol> {
-    fn to_slice(&self) -> Cow<'static, [Syllable]> {
-        self.iter()
-            .map_while(|&sym| match sym {
-                Symbol::Syllable(syl) => Some(syl),
-                Symbol::Char(_) => None,
-            })
-            .collect::<Vec<_>>()
-            .into()
-    }
-}
-
 /// Input data collected by the Editor.
 #[derive(Debug, Default, Clone)]
 pub struct Composition {

src/dictionary/layered.rs

@@ -5,7 +5,7 @@ use std::{
 
 use log::error;
 
-use crate::zhuyin::SyllableSlice;
+use crate::zhuyin::Syllable;
 
 use super::{
     Dictionary, DictionaryInfo, DictionaryMut, Entries, LookupStrategy, Phrase,
@@ -83,7 +83,7 @@ impl Dictionary for Layered {
     /// ```
     fn lookup_first_n_phrases(
         &self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         first: usize,
         strategy: LookupStrategy,
     ) -> Vec<Phrase> {
@@ -159,7 +159,7 @@ impl DictionaryMut for Layered {
 
     fn add_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
     ) -> Result<(), UpdateDictionaryError> {
         if phrase.as_str().is_empty() {
@@ -175,7 +175,7 @@ impl DictionaryMut for Layered {
 
     fn update_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
         user_freq: u32,
         time: u64,
@@ -193,7 +193,7 @@ impl DictionaryMut for Layered {
 
     fn remove_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase_str: &str,
     ) -> Result<(), UpdateDictionaryError> {
         if let Some(writer) = self.user_dict.as_dict_mut() {

src/dictionary/mod.rs

@@ -10,7 +10,7 @@ use std::{
     path::Path,
 };
 
-use crate::zhuyin::{Syllable, SyllableSlice};
+use crate::zhuyin::Syllable;
 
 pub use layered::Layered;
 pub use loader::{
@@ -343,7 +343,7 @@ pub trait Dictionary: Debug {
     /// The result should use a stable order each time for the same input.
     fn lookup_first_n_phrases(
         &self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         first: usize,
         strategy: LookupStrategy,
     ) -> Vec<Phrase>;
@@ -352,7 +352,7 @@ pub trait Dictionary: Debug {
     /// The result should use a stable order each time for the same input.
     fn lookup_first_phrase(
         &self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         strategy: LookupStrategy,
     ) -> Option<Phrase> {
         self.lookup_first_n_phrases(syllables, 1, strategy)
@@ -362,11 +362,7 @@ pub trait Dictionary: Debug {
     /// Returns all phrases matched by the syllables.
     ///
     /// The result should use a stable order each time for the same input.
-    fn lookup_all_phrases(
-        &self,
-        syllables: &dyn SyllableSlice,
-        strategy: LookupStrategy,
-    ) -> Vec<Phrase> {
+    fn lookup_all_phrases(&self, syllables: &[Syllable], strategy: LookupStrategy) -> Vec<Phrase> {
         self.lookup_first_n_phrases(syllables, usize::MAX, strategy)
     }
     /// Returns an iterator to all phrases in the dictionary.
@@ -410,14 +406,14 @@ pub trait DictionaryMut: Debug {
     /// TODO: doc
     fn add_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
     ) -> Result<(), UpdateDictionaryError>;
 
     /// TODO: doc
     fn update_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
         user_freq: u32,
         time: u64,
@@ -426,7 +422,7 @@ pub trait DictionaryMut: Debug {
     /// TODO: doc
     fn remove_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase_str: &str,
     ) -> Result<(), UpdateDictionaryError>;
 }

src/dictionary/sqlite.rs

@@ -8,7 +8,7 @@ use std::{
 
 use rusqlite::{Connection, Error as RusqliteError, OpenFlags, OptionalExtension, params};
 
-use crate::zhuyin::{Syllable, SyllableSlice};
+use crate::zhuyin::Syllable;
 
 use super::{
     BuildDictionaryError, Dictionary, DictionaryBuilder, DictionaryInfo, DictionaryMut, Entries,
@@ -18,6 +18,21 @@ use super::{
 const APPLICATION_ID: u32 = 0x43484557; // 'CHEW' in big-endian
 const USER_VERSION: u32 = 0;
 
+/// A slice that can be converted to a slice of syllables.
+trait SyllableSlice {
+    fn to_bytes(&self) -> Vec<u8>;
+}
+
+impl SyllableSlice for &[Syllable] {
+    fn to_bytes(&self) -> Vec<u8> {
+        let mut syllables_bytes = vec![];
+        self.iter().for_each(|syl| {
+            syllables_bytes.extend_from_slice(&syl.as_ref().to_u16().to_le_bytes())
+        });
+        syllables_bytes
+    }
+}
+
 /// TODO: doc
 #[derive(Debug)]
 #[non_exhaustive]
@@ -300,7 +315,7 @@ impl From<RusqliteError> for UpdateDictionaryError {
 impl Dictionary for SqliteDictionary {
     fn lookup_first_n_phrases(
         &self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         first: usize,
         strategy: LookupStrategy,
     ) -> Vec<Phrase> {
@@ -392,7 +407,7 @@ impl DictionaryMut for SqliteDictionary {
 
     fn add_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
     ) -> Result<(), UpdateDictionaryError> {
         if self.readonly {
@@ -414,7 +429,7 @@ impl DictionaryMut for SqliteDictionary {
 
     fn update_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase: Phrase,
         user_freq: u32,
         time: u64,
@@ -468,7 +483,7 @@ impl DictionaryMut for SqliteDictionary {
 
     fn remove_phrase(
         &mut self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         phrase_str: &str,
     ) -> Result<(), UpdateDictionaryError> {
         let syllables_bytes = syllables.to_bytes();

src/dictionary/trie.rs

@@ -19,7 +19,7 @@ use der::{
 };
 use log::{error, warn};
 
-use crate::zhuyin::{Syllable, SyllableSlice};
+use crate::zhuyin::Syllable;
 
 use super::{
     BuildDictionaryError, Dictionary, DictionaryBuilder, DictionaryInfo, Entries, LookupStrategy,
@@ -260,7 +260,7 @@ macro_rules! iter_bail_if_oob {
 impl Dictionary for Trie {
     fn lookup_first_n_phrases(
         &self,
-        syllables: &dyn SyllableSlice,
+        syllables: &[Syllable],
         first: usize,
         strategy: LookupStrategy,
     ) -> Vec<Phrase> {
@@ -293,7 +293,7 @@ impl Dictionary for Trie {
         // Perform a BFS search to find all leaf nodes
         let mut threads: VecDeque<TrieNodeView<'_>> = VecDeque::new();
         threads.push_back(root);
-        for syl in syllables.to_slice().iter() {
+        for syl in syllables {
             debug_assert!(syl.to_u16() != 0);
             for _ in 0..threads.len() {
                 let node = threads.pop_front().unwrap();