Lindera

A morphological analysis library in Rust. This project fork from kuromoji-rs.

Lindera aims to build a library which is easy to install and provides concise APIs for various Rust applications.

The following products are required to build:

• Rust >= 1.46.0

Tokenization examples

Basic tokenization

Put the following in Cargo.toml:

[dependencies]
lindera = { version = "0.37.0", features = ["ipadic"] }

This example covers the basic usage of Lindera.

It will:

• Create a tokenizer in normal mode
• Tokenize the input text
• Output the tokens

use lindera::dictionary::{load_dictionary_from_kind, DictionaryKind};
use lindera::mode::Mode;
use lindera::segmenter::Segmenter;
use lindera::tokenizer::Tokenizer;
use lindera::LinderaResult;

fn main() -> LinderaResult<()> {
    let mut config_builder = TokenizerConfigBuilder::new();
    config_builder.set_segmenter_dictionary_kind(&DictionaryKind::IPADIC);
    config_builder.set_segmenter_mode(&Mode::Normal);

    let dictionary = load_dictionary_from_kind(DictionaryKind::IPADIC)?;
    let segmenter = Segmenter::new(
        Mode::Normal,
        dictionary,
        None, // Assuming no user dictionary is provided
    );

    // Create a tokenizer.
    let tokenizer = Tokenizer::new(segmenter);

    // Tokenize a text.
    let text = "関西国際空港限定トートバッグ";
    let mut tokens = tokenizer.tokenize(text)?;

    // Print the text and tokens.
    println!("text:\t{}", text);
    for token in tokens.iter_mut() {
        let details = token.details().join(",");
        println!("token:\t{}\t{}", token.text.as_ref(), details);
    }

    Ok(())
}

The above example can be run as follows:

% cargo run --features=ipadic --example=tokenize

You can see the result as follows:

text:   関西国際空港限定トートバッグ
token:  関西国際空港    名詞,固有名詞,組織,*,*,*,関西国際空港,カンサイコクサイクウコウ,カンサイコクサイクーコー
token:  限定    名詞,サ変接続,*,*,*,*,限定,ゲンテイ,ゲンテイ
token:  トートバッグ    UNK

Tokenization with user dictionary

You can give user dictionary entries along with the default system dictionary. User dictionary should be a CSV with following format.

<surface>,<part_of_speech>,<reading>

Put the following in Cargo.toml:

[dependencies]
lindera = { version = "0.34.0", features = ["ipadic"] }

For example:

% cat ./resources/simple_userdic.csv
東京スカイツリー,カスタム名詞,トウキョウスカイツリー
東武スカイツリーライン,カスタム名詞,トウブスカイツリーライン
とうきょうスカイツリー駅,カスタム名詞,トウキョウスカイツリーエキ

With an user dictionary, Tokenizer will be created as follows:

use std::path::PathBuf;

use lindera::dictionary::{
    load_dictionary_from_kind, load_user_dictionary_from_csv, DictionaryKind,
};
use lindera::mode::Mode;
use lindera::segmenter::Segmenter;
use lindera::tokenizer::Tokenizer;
use lindera::LinderaResult;

fn main() -> LinderaResult<()> {
    let user_dict_path = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("../resources")
        .join("ipadic_simple_userdic.csv");

    let dictionary = load_dictionary_from_kind(DictionaryKind::IPADIC)?;
    let user_dictionary =
        load_user_dictionary_from_csv(DictionaryKind::IPADIC, PathBuf::from("./resources/ipadic_simple_userdic.csv").as_path())?;
    let segmenter = Segmenter::new(
        Mode::Normal,
        dictionary,
        Some(user_dictionary), // Assuming no user dictionary is provided
    );

    // Create a tokenizer.
    let tokenizer = Tokenizer::new(segmenter);

    // Tokenize a text.
    let text = "東京スカイツリーの最寄り駅はとうきょうスカイツリー駅です";
    let mut tokens = tokenizer.tokenize(text)?;

    // Print the text and tokens.
    println!("text:\t{}", text);
    for token in tokens.iter_mut() {
        let details = token.details().join(",");
        println!("token:\t{}\t{}", token.text.as_ref(), details);
    }

    Ok(())
}

The above example can be by cargo run --example:

% cargo run --features=ipadic --example=tokenize_with_user_dict
text:   東京スカイツリーの最寄り駅はとうきょうスカイツリー駅です
token:  東京スカイツリー        カスタム名詞,*,*,*,*,*,東京スカイツリー,トウキョウスカイツリー,*
token:  の      助詞,連体化,*,*,*,*,の,ノ,ノ
token:  最寄り駅        名詞,一般,*,*,*,*,最寄り駅,モヨリエキ,モヨリエキ
token:  は      助詞,係助詞,*,*,*,*,は,ハ,ワ
token:  とうきょうスカイツリー駅        カスタム名詞,*,*,*,*,*,とうきょうスカイツリー駅,トウキョウスカイツリーエキ,*
token:  です    助動詞,*,*,*,特殊・デス,基本形,です,デス,デス

Tokenize with filters

Put the following in Cargo.toml:

[dependencies]
lindera = { version = "0.34.0", features = ["ipadic"] }

This example covers the basic usage of Lindera Analysis Framework.

It will:

• Apply character filter for Unicode normalization (NFKC)
• Tokenize the input text with IPADIC
• Apply token filters for removing stop tags (Part-of-speech) and Japanese Katakana stem filter

use std::collections::HashSet;

use lindera::character_filter::japanese_iteration_mark::JapaneseIterationMarkCharacterFilter;
use lindera::character_filter::unicode_normalize::{
    UnicodeNormalizeCharacterFilter, UnicodeNormalizeKind,
};
use lindera::character_filter::BoxCharacterFilter;
use lindera::dictionary::{load_dictionary_from_kind, DictionaryKind};
use lindera::mode::Mode;
use lindera::segmenter::Segmenter;
use lindera::token_filter::japanese_compound_word::JapaneseCompoundWordTokenFilter;
use lindera::token_filter::japanese_number::JapaneseNumberTokenFilter;
use lindera::token_filter::japanese_stop_tags::JapaneseStopTagsTokenFilter;
use lindera::token_filter::BoxTokenFilter;
use lindera::tokenizer::Tokenizer;
use lindera::LinderaResult;

fn main() -> LinderaResult<()> {
    let dictionary = load_dictionary_from_kind(DictionaryKind::IPADIC)?;
    let segmenter = Segmenter::new(
        Mode::Normal,
        dictionary,
        None, // Assuming no user dictionary is provided
    );

    let unicode_normalize_char_filter =
        UnicodeNormalizeCharacterFilter::new(UnicodeNormalizeKind::NFKC);

    let japanese_iterration_mark_char_filter =
        JapaneseIterationMarkCharacterFilter::new(true, true);

    let japanese_compound_word_token_filter = JapaneseCompoundWordTokenFilter::new(
        DictionaryKind::IPADIC,
        vec!["名詞,数".to_string(), "名詞,接尾,助数詞".to_string()]
            .into_iter()
            .collect(),
        Some("複合語".to_string()),
    );

    let japanese_number_token_filter =
        JapaneseNumberTokenFilter::new(Some(vec!["名詞,数".to_string()].into_iter().collect()));

    let japanese_stop_tags_token_filter = JapaneseStopTagsTokenFilter::new(
        vec![
            "接続詞".to_string(),
            "助詞".to_string(),
            "助詞,格助詞".to_string(),
            "助詞,格助詞,一般".to_string(),
            "助詞,格助詞,引用".to_string(),
            "助詞,格助詞,連語".to_string(),
            "助詞,係助詞".to_string(),
            "助詞,副助詞".to_string(),
            "助詞,間投助詞".to_string(),
            "助詞,並立助詞".to_string(),
            "助詞,終助詞".to_string(),
            "助詞,副助詞／並立助詞／終助詞".to_string(),
            "助詞,連体化".to_string(),
            "助詞,副詞化".to_string(),
            "助詞,特殊".to_string(),
            "助動詞".to_string(),
            "記号".to_string(),
            "記号,一般".to_string(),
            "記号,読点".to_string(),
            "記号,句点".to_string(),
            "記号,空白".to_string(),
            "記号,括弧閉".to_string(),
            "その他,間投".to_string(),
            "フィラー".to_string(),
            "非言語音".to_string(),
        ]
        .into_iter()
        .collect(),
    );

    // Create a tokenizer.
    let mut tokenizer = Tokenizer::new(segmenter);

    tokenizer
        .append_character_filter(BoxCharacterFilter::from(unicode_normalize_char_filter))
        .append_character_filter(BoxCharacterFilter::from(
            japanese_iterration_mark_char_filter,
        ))
        .append_token_filter(BoxTokenFilter::from(japanese_compound_word_token_filter))
        .append_token_filter(BoxTokenFilter::from(japanese_number_token_filter))
        .append_token_filter(BoxTokenFilter::from(japanese_stop_tags_token_filter));

    // Tokenize a text.
    let text = "Ｌｉｎｄｅｒａは形態素解析ｴﾝｼﾞﾝです。ユーザー辞書も利用可能です。";
    let tokens = tokenizer.tokenize(text)?;

    // Print the text and tokens.
    println!("text: {}", text);
    for token in tokens {
        println!(
            "token: {:?}, start: {:?}, end: {:?}, details: {:?}",
            token.text, token.byte_start, token.byte_end, token.details
        );
    }

    Ok(())
}

The above example can be run as follows:

% cargo run --features=ipadic --example=tokenize_with_filters

You can see the result as follows:

text: Ｌｉｎｄｅｒａは形態素解析ｴﾝｼﾞﾝです。ユーザー辞書も利用可能です。
token: "Lindera", start: 0, end: 21, details: Some(["UNK"])
token: "形態素", start: 24, end: 33, details: Some(["名詞", "一般", "*", "*", "*", "*", "形態素", "ケイタイソ", "ケイタイソ"])
token: "解析", start: 33, end: 39, details: Some(["名詞", "サ変接続", "*", "*", "*", "*", "解析", "カイセキ", "カイセキ"])
token: "エンジン", start: 39, end: 54, details: Some(["名詞", "一般", "*", "*", "*", "*", "エンジン", "エンジン", "エンジン"])
token: "ユーザー", start: 63, end: 75, details: Some(["名詞", "一般", "*", "*", "*", "*", "ユーザー", "ユーザー", "ユーザー"])
token: "辞書", start: 75, end: 81, details: Some(["名詞", "一般", "*", "*", "*", "*", "辞書", "ジショ", "ジショ"])
token: "利用", start: 84, end: 90, details: Some(["名詞", "サ変接続", "*", "*", "*", "*", "利用", "リヨウ", "リヨー"])
token: "可能", start: 90, end: 96, details: Some(["名詞", "形容動詞語幹", "*", "*", "*", "*", "可能", "カノウ", "カノー"])

Configuration file

Lindera is able to read YAML format configuration files. Specify the path to the following file in the environment variable LINDERA_CONFIG_PATH. You can use it easily without having to code the behavior of the tokenizer in Rust code.

segmenter:
  mode: "normal"
  dictionary:
    kind: "ipadic"
  user_dictionary:
    path: "./resources/ipadic_simple.csv"
    kind: "ipadic"

character_filters:
  - kind: "unicode_normalize"
    args:
      kind: "nfkc"
  - kind: "japanese_iteration_mark"
    args:
      normalize_kanji: true
      normalize_kana: true
  - kind: mapping
    args:
       mapping:
         リンデラ: Lindera

token_filters:
  - kind: "japanese_compound_word"
    args:
      kind: "ipadic"
      tags:
        - "名詞,数"
        - "名詞,接尾,助数詞"
      new_tag: "名詞,数"
  - kind: "japanese_number"
    args:
      tags:
        - "名詞,数"
  - kind: "japanese_stop_tags"
    args:
      tags:
        - "接続詞"
        - "助詞"
        - "助詞,格助詞"
        - "助詞,格助詞,一般"
        - "助詞,格助詞,引用"
        - "助詞,格助詞,連語"
        - "助詞,係助詞"
        - "助詞,副助詞"
        - "助詞,間投助詞"
        - "助詞,並立助詞"
        - "助詞,終助詞"
        - "助詞,副助詞／並立助詞／終助詞"
        - "助詞,連体化"
        - "助詞,副詞化"
        - "助詞,特殊"
        - "助動詞"
        - "記号"
        - "記号,一般"
        - "記号,読点"
        - "記号,句点"
        - "記号,空白"
        - "記号,括弧閉"
        - "その他,間投"
        - "フィラー"
        - "非言語音"
  - kind: "japanese_katakana_stem"
    args:
      min: 3
  - kind: "remove_diacritical_mark"
    args:
      japanese: false

% export LINDERA_CONFIG_PATH=./resources/lindera.yml

use lindera::tokenizer::TokenizerBuilder;
use lindera::LinderaResult;

fn main() -> LinderaResult<()> {
    // Creates a new `TokenizerConfigBuilder` instance.
    // If the `LINDERA_CONFIG_PATH` environment variable is set, it will attempt to load the initial settings from the specified path.
    let builder = TokenizerBuilder::from_file(PathBuf::from("./resources/lindera.yml").as_path())?;

    let tokenizer = builder.build()?;

    // Tokenize a text.
    let text = "関西国際空港限定トートバッグ";
    let mut tokens = tokenizer.tokenize(text)?;

    // Print the text and tokens.
    println!("text:\t{}", text);
    for token in tokens.iter_mut() {
        let details = token.details().join(",");
        println!("token:\t{}\t{}", token.text.as_ref(), details);
    }

    Ok(())
}

API reference

The API reference is available. Please see following URL:

• lindera