# mecab-rs [](https://travis-ci.org/tsurai/mecab-rs)
Safe Rust wrapper for [mecab](https://taku910.github.io/mecab/) a japanese language part-of-speech and morphological analyzer library.
## Usage
The wrapper is almost identical to the C++ interface of mecab with the addition of various iterator for comfortable data access. A detailed documentation of the wrapper will follow when Rust 1.0 is finally out and stable.
The basic usage can be seen in the following examples.
## Examples
Include this in your Cargo.toml to add mecab to your project:
```toml
[dependencies]
mecab = "*"
```
### Single-threaded environment
```Rust
extern crate mecab;
use mecab::Tagger;
fn main() {
let input = "太郎は次郎が持っている本を花子に渡した。";
println!("INPUT: {}", input);
let mut tagger = Tagger::new("");
// gets tagged result as String
let mut result = tagger.parse_str(input);
println!("RESULT: {}", result);
// gets N best results as String
result = tagger.parse_nbest(3, input);
println!("NBEST:\n{}", result);
// gets N best in sequence
tagger.parse_nbest_init(input);
for i in (0..3) {
if let Some(res) = tagger.next() {
println!("{}:\n{}", i, res);
}
}
// gets Node object
for node in tagger.parse_to_node(input).iter_next() {
match node.stat as i32 {
mecab::MECAB_BOS_NODE => {
print!("{} BOS ", node.id);
},
mecab::MECAB_EOS_NODE => {
print!("{} EOS ", node.id);
},
_ => {
print!("{} {} ", node.id, &(node.surface)[..(node.length as usize)]);
}
}
println!("{} {} {} {} {} {} {} {} {} {} {} {} {}",
node.feature,
input.len() as isize - node.surface.len() as isize,
input.len() as isize - node.surface.len() as isize + node.length as isize,
node.rcattr,
node.lcattr,
node.posid,
node.char_type,
node.stat,
node.isbest,
node.alpha,
node.beta,
node.prob,
node.cost);
}
// dictionary info
for dict in tagger.dictionary_info().iter() {
println!("\nfilename: {}", dict.filename);
println!("charset: {}", dict.charset);
println!("size: {}", dict.size);
println!("type: {}", dict.dict_type);
println!("lsize: {}", dict.lsize);
println!("rsize: {}", dict.rsize);
println!("version: {}", dict.version);
}
}
```
## Multithreaded environment
```Rust
extern crate mecab;
use mecab::Model;
fn main() {
let input = "太郎は次郎が持っている本を花子に渡した。";
// create model object
let model = Model::new("");
// create tagger based on the model
let mut tagger = model.create_tagger();
// create lattice object per thread
let mut lattice = model.create_lattice();
// get tagged result as string
lattice.set_sentence(input);
// parse lattice
tagger.parse(&lattice);
println!("{}", lattice.to_string());
// iterate over node objects
for node in lattice.bos_node().iter_next() {
match node.stat as i32 {
mecab::MECAB_BOS_NODE => {
print!("{} BOS ", node.id);
},
mecab::MECAB_EOS_NODE => {
print!("{} EOS ", node.id);
},
_ => {
print!("{} {} ", node.id, &(node.surface)[..(node.length as usize)]);
}
}
println!("{} {} {} {} {} {} {} {} {} {} {} {} {}",
node.feature,
input.len() as isize - node.surface.len() as isize,
input.len() as isize - node.surface.len() as isize + node.length as isize,
node.rcattr,
node.lcattr,
node.posid,
node.char_type,
node.stat,
node.isbest,
node.alpha,
node.beta,
node.prob,
node.cost);
}
// iterate over begin and end nodes
let len = lattice.size();
for i in (0..len+1) {
let b = lattice.begin_nodes(i);
let e = lattice.end_nodes(i);
if let Some(nodes) = b {
for node in nodes.iter_bnext() {
println!("B[{}] {}\t{}", i, node.surface, node.feature);
}
}
if let Some(nodes) = e {
for node in nodes.iter_enext() {
println!("E[{}] {}\t{}", i, node.surface, node.feature);
}
}
}
// get N best results
lattice.set_request_type(mecab::MECAB_NBEST);
lattice.set_sentence(input);
tagger.parse(&lattice);
for i in (0..10) {
println!("NBEST: {}", i);
println!("{}", lattice.to_string());
if !lattice.next() {
break;
}
}
// marginal probabilities
lattice.remove_request_type(mecab::MECAB_NBEST);
lattice.set_request_type(mecab::MECAB_MARGINAL_PROB);
lattice.set_sentence(input);
tagger.parse(&lattice);
println!("{}", lattice.theta());
for node in lattice.bos_node().iter_next() {
println!("{}\t{}\t{}", &(node.surface)[..(node.length as usize)], node.feature, node.prob);
}
// dictionary info
for dict in model.dictionary_info().iter() {
println!("\nfilename: {}", dict.filename);
println!("charset: {}", dict.charset);
println!("size: {}", dict.size);
println!("type: {}", dict.dict_type);
println!("lsize: {}", dict.lsize);
println!("rsize: {}", dict.rsize);
println!("version: {}", dict.version);
}
}
```
## License
The MIT License (MIT)
Copyright (c) 2015 Cristian Kubis
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.