lindera_dictionary/dictionary/
unknown_dictionary.rs

1use std::str::FromStr;
2
3use log::warn;
4use rkyv::{Archive, Deserialize as RkyvDeserialize, Serialize as RkyvSerialize};
5use serde::{Deserialize, Serialize};
6
7use crate::LinderaResult;
8use crate::dictionary::character_definition::CategoryId;
9use crate::error::LinderaErrorKind;
10use crate::viterbi::WordEntry;
11
12#[derive(Serialize, Deserialize, Clone, Archive, RkyvSerialize, RkyvDeserialize)]
13
14pub struct UnknownDictionary {
15    pub category_references: Vec<Vec<u32>>,
16    pub costs: Vec<WordEntry>,
17    /// Byte offset for each entry's details in `words_data`.
18    pub words_idx_data: Vec<u32>,
19    /// Packed details bytes: for each entry, 4-byte LE length followed by
20    /// NUL-separated detail fields (e.g. "名詞\0一般\0*\0...").
21    pub words_data: Vec<u8>,
22}
23
24impl UnknownDictionary {
25    pub fn load(unknown_data: &[u8]) -> LinderaResult<UnknownDictionary> {
26        let mut aligned = rkyv::util::AlignedVec::<16>::new();
27        aligned.extend_from_slice(unknown_data);
28        rkyv::from_bytes::<UnknownDictionary, rkyv::rancor::Error>(&aligned).map_err(|err| {
29            LinderaErrorKind::Deserialize.with_error(anyhow::anyhow!(err.to_string()))
30        })
31    }
32
33    pub fn word_entry(&self, word_id: u32) -> WordEntry {
34        self.costs[word_id as usize]
35    }
36
37    pub fn lookup_word_ids(&self, category_id: CategoryId) -> &[u32] {
38        &self.category_references[category_id.0][..]
39    }
40
41    /// Retrieve the detail fields (POS, etc.) for an unknown word entry.
42    pub fn word_details(&self, word_id: u32) -> Option<Vec<&str>> {
43        let idx = word_id as usize;
44        if idx >= self.words_idx_data.len() {
45            return None;
46        }
47        let offset = self.words_idx_data[idx] as usize;
48        if offset + 4 > self.words_data.len() {
49            return None;
50        }
51        let len = u32::from_le_bytes(self.words_data[offset..offset + 4].try_into().ok()?) as usize;
52        if offset + 4 + len > self.words_data.len() {
53            return None;
54        }
55        let text = std::str::from_utf8(&self.words_data[offset + 4..offset + 4 + len]).ok()?;
56        Some(text.split('\0').collect())
57    }
58
59    /// Unknown word generation with callback system
60    pub fn gen_unk_words<F>(
61        &self,
62        sentence: &str,
63        start_pos: usize,
64        has_matched: bool,
65        max_grouping_len: Option<usize>,
66        mut callback: F,
67    ) where
68        F: FnMut(UnkWord),
69    {
70        let chars: Vec<char> = sentence.chars().collect();
71        let max_len = max_grouping_len.unwrap_or(10);
72
73        // Limit based on dictionary matches for efficiency
74        let actual_max_len = if has_matched { 1 } else { max_len.min(3) };
75
76        for length in 1..=actual_max_len {
77            if start_pos + length > chars.len() {
78                break;
79            }
80
81            let end_pos = start_pos + length;
82
83            // Classify character type for unknown word
84            let first_char = chars[start_pos];
85            let char_type = classify_char_type(first_char);
86
87            // Create unknown word entry
88            let unk_word = UnkWord {
89                word_idx: WordIdx::new(char_type as u32),
90                end_char: end_pos,
91            };
92
93            callback(unk_word);
94        }
95    }
96
97    /// Check compatibility with unknown word based on feature matching
98    pub fn compatible_unk_index(
99        &self,
100        sentence: &str,
101        start: usize,
102        _end: usize,
103        feature: &str,
104    ) -> Option<WordIdx> {
105        let chars: Vec<char> = sentence.chars().collect();
106        if start >= chars.len() {
107            return None;
108        }
109
110        let first_char = chars[start];
111        let char_type = classify_char_type(first_char);
112
113        // Simple compatibility check based on feature string
114        if feature.starts_with(&format!("名詞,{}", get_type_name(char_type))) {
115            Some(WordIdx::new(char_type as u32))
116        } else {
117            None
118        }
119    }
120}
121
122/// Unknown word structure for callback system
123#[derive(Debug, Clone)]
124pub struct UnkWord {
125    pub word_idx: WordIdx,
126    pub end_char: usize,
127}
128
129impl UnkWord {
130    pub fn word_idx(&self) -> WordIdx {
131        self.word_idx
132    }
133
134    pub fn end_char(&self) -> usize {
135        self.end_char
136    }
137}
138
139#[derive(Debug, Clone, Copy)]
140pub struct WordIdx {
141    pub word_id: u32,
142}
143
144impl WordIdx {
145    pub fn new(word_id: u32) -> Self {
146        Self { word_id }
147    }
148}
149
150/// Classify character type (compatible with existing system)
151fn classify_char_type(ch: char) -> usize {
152    if ch.is_ascii_digit() {
153        5 // NUMERIC
154    } else if ch.is_ascii_alphabetic() {
155        4 // ALPHA
156    } else if is_kanji(ch) {
157        3 // KANJI
158    } else if is_katakana(ch) {
159        2 // KATAKANA
160    } else if is_hiragana(ch) {
161        1 // HIRAGANA
162    } else {
163        0 // DEFAULT
164    }
165}
166
167fn get_type_name(char_type: usize) -> &'static str {
168    match char_type {
169        1 => "一般",
170        2 => "一般",
171        3 => "一般",
172        4 => "固有名詞",
173        5 => "数",
174        _ => "一般",
175    }
176}
177
178/// Character classification helpers
179fn is_hiragana(ch: char) -> bool {
180    matches!(ch, '\u{3041}'..='\u{3096}')
181}
182
183fn is_katakana(ch: char) -> bool {
184    matches!(ch, '\u{30A1}'..='\u{30F6}' | '\u{30F7}'..='\u{30FA}' | '\u{31F0}'..='\u{31FF}')
185}
186
187fn is_kanji(ch: char) -> bool {
188    matches!(ch, '\u{4E00}'..='\u{9FAF}' | '\u{3400}'..='\u{4DBF}')
189}
190
191#[derive(Debug)]
192pub struct UnknownDictionaryEntry {
193    pub surface: String,
194    pub left_id: u32,
195    pub right_id: u32,
196    pub word_cost: i32,
197}
198
199fn parse_dictionary_entry(
200    fields: &[&str],
201    expected_fields_len: usize,
202) -> LinderaResult<UnknownDictionaryEntry> {
203    if fields.len() != expected_fields_len {
204        return Err(LinderaErrorKind::Content.with_error(anyhow::anyhow!(
205            "Invalid number of fields. Expect {}, got {}",
206            expected_fields_len,
207            fields.len()
208        )));
209    }
210    let surface = fields[0];
211    let left_id = u32::from_str(fields[1])
212        .map_err(|err| LinderaErrorKind::Parse.with_error(anyhow::anyhow!(err)))?;
213    let right_id = u32::from_str(fields[2])
214        .map_err(|err| LinderaErrorKind::Parse.with_error(anyhow::anyhow!(err)))?;
215    let word_cost = i32::from_str(fields[3])
216        .map_err(|err| LinderaErrorKind::Parse.with_error(anyhow::anyhow!(err)))?;
217
218    Ok(UnknownDictionaryEntry {
219        surface: surface.to_string(),
220        left_id,
221        right_id,
222        word_cost,
223    })
224}
225
226fn get_entry_id_matching_surface(
227    entries: &[UnknownDictionaryEntry],
228    target_surface: &str,
229) -> Vec<u32> {
230    entries
231        .iter()
232        .enumerate()
233        .filter_map(|(entry_id, entry)| {
234            if entry.surface == *target_surface {
235                Some(entry_id as u32)
236            } else {
237                None
238            }
239        })
240        .collect()
241}
242
243fn make_category_references(
244    categories: &[String],
245    entries: &[UnknownDictionaryEntry],
246) -> Vec<Vec<u32>> {
247    categories
248        .iter()
249        .map(|category| get_entry_id_matching_surface(entries, category))
250        .collect()
251}
252
253fn make_costs_array(
254    entries: &[UnknownDictionaryEntry],
255    remap: Option<&crate::dictionary::context_id_map::ContextIdMap>,
256) -> Vec<WordEntry> {
257    entries
258        .iter()
259        .enumerate()
260        .map(|(i, e)| {
261            // Do not perform strict checks on left context id and right context id in unk.def.
262            // Just output a warning.
263            if e.left_id != e.right_id {
264                warn!("left id and right id are not same: {e:?}");
265            }
266            let (left_id, right_id) = (e.left_id as u16, e.right_id as u16);
267            // Relabel to match the remapped connection matrix. `get().unwrap_or`
268            // leaves an out-of-range id untouched (it would fail the matrix build).
269            let (left_id, right_id) = match remap {
270                Some(m) => (
271                    m.left.get(left_id as usize).copied().unwrap_or(left_id),
272                    m.right.get(right_id as usize).copied().unwrap_or(right_id),
273                ),
274                None => (left_id, right_id),
275            };
276            WordEntry::new(
277                crate::viterbi::WordId::new(crate::viterbi::LexType::Unknown, i as u32),
278                e.word_cost as i16,
279                left_id,
280                right_id,
281            )
282        })
283        .collect()
284}
285
286pub fn parse_unk(
287    categories: &[String],
288    file_content: &str,
289    remap: Option<&crate::dictionary::context_id_map::ContextIdMap>,
290) -> LinderaResult<UnknownDictionary> {
291    let mut unknown_dict_entries = Vec::new();
292    let mut words_idx_data = Vec::new();
293    let mut words_data: Vec<u8> = Vec::new();
294
295    for line in file_content.lines() {
296        let fields: Vec<&str> = line.split(',').collect::<Vec<&str>>();
297        let entry = parse_dictionary_entry(&fields[..], fields.len())?;
298        unknown_dict_entries.push(entry);
299
300        // Store detail fields (columns after the first 4: category, left_id, right_id, cost)
301        let offset = words_data.len() as u32;
302        words_idx_data.push(offset);
303
304        let details = if fields.len() > 4 {
305            fields[4..].join("\0")
306        } else {
307            String::new()
308        };
309        let details_bytes = details.as_bytes();
310        let len = details_bytes.len() as u32;
311        words_data.extend_from_slice(&len.to_le_bytes());
312        words_data.extend_from_slice(details_bytes);
313    }
314
315    let category_references = make_category_references(categories, &unknown_dict_entries[..]);
316    let costs = make_costs_array(&unknown_dict_entries[..], remap);
317    Ok(UnknownDictionary {
318        category_references,
319        costs,
320        words_idx_data,
321        words_data,
322    })
323}
lindera_dictionary/dictionary/unknown_dictionary.rs

lindera_dictionary/dictionary/
unknown_dictionary.rs
