Crate opencc_fmmseg 

Fast Chinese text conversion with OpenCC dictionaries and forward maximum matching segmentation.

opencc-fmmseg converts between Simplified Chinese, Traditional Chinese, Taiwan, Hong Kong, and Japanese kanji variants using bundled OpenCC-style dictionaries. The default constructor loads a compressed dictionary embedded in the crate, so normal use does not require runtime dictionary files.

Quick Start

use opencc_fmmseg::{OpenCC, OpenccConfig};

let converter = OpenCC::new();

let traditional = converter.convert_with_config(
    "汉字转换测试",
    OpenccConfig::S2t,
    false,
);

assert_eq!(traditional, "漢字轉換測試");

Choosing an API

• OpenCC is the main converter type.
• OpenccConfig is the recommended Rust configuration API.
• OpenCC::convert accepts OpenCC-style strings such as "s2t" and is useful for CLI/config-file compatibility.
• DictionaryMaxlength and CustomDictSpec are for advanced users who need custom dictionaries or externally generated dictionary artifacts.

Supported Configurations

Config	Method	Meaning
s2t	OpenCC::s2t	Simplified to Traditional
t2s	OpenCC::t2s	Traditional to Simplified
s2tw / s2twp	OpenCC::s2tw / OpenCC::s2twp	Simplified to Taiwan Traditional
tw2s / tw2sp	OpenCC::tw2s / OpenCC::tw2sp	Taiwan Traditional to Simplified
s2hk / t2hk	OpenCC::s2hk / OpenCC::t2hk	To Hong Kong Traditional variants
hk2s / hk2t	OpenCC::hk2s / OpenCC::hk2t	Hong Kong variants to Simplified/Traditional
t2tw / t2twp	OpenCC::t2tw / OpenCC::t2twp	Traditional to Taiwan variants
tw2t / tw2tp	OpenCC::tw2t / OpenCC::tw2tp	Taiwan variants to Traditional
t2jp / jp2t	OpenCC::t2jp / OpenCC::jp2t	Traditional and Japanese kanji variants

Custom Dictionaries

use opencc_fmmseg::{
    CustomDictMode, CustomDictSpec, DictSlot, DictionaryMaxlength, OpenCC,
};

let dictionary = DictionaryMaxlength::from_zstd()?
    .with_custom_dicts(&[CustomDictSpec {
        slot: DictSlot::STPhrases,
        pairs: vec![("帕兰蒂尔".to_string(), "柏蘭蒂爾".to_string())],
        mode: CustomDictMode::Append,
    }])?;

let converter = OpenCC::from_dictionary(dictionary);
assert_eq!(
    converter.convert("帕兰蒂尔", "s2t", false),
    "柏蘭蒂爾"
);

Error Reporting

Most high-level conversion methods return a String for compatibility with the C and scripting-language bindings. Non-fatal setup or configuration errors are recorded in OpenCC::get_last_error. Dictionary construction APIs return Result with DictionaryError.

Re-exports

pub use crate::dictionary_lib::CustomDictFileSpec;

pub use crate::dictionary_lib::CustomDictMode;

pub use crate::dictionary_lib::CustomDictSpec;

pub use crate::dictionary_lib::DictSlot;

pub use crate::dictionary_lib::DictionaryError;

pub use crate::dictionary_lib::DictionaryMaxlength;

Modules

dictionary_lib

Dictionary utilities for managing multiple OpenCC lexicons. Internal dictionary-processing utilities for opencc-fmmseg.

Macros

debug_note

Print a developer note to stderr in debug builds; no-op in release.

Structs

DelimiterSet

Compact, hot-path-friendly delimiter set optimized for per-character membership tests.

DictRefs

Holds up to three conversion rounds. Each round carries its own dictionaries, max_len, and prebuilt StarterUnion.

OpenCC

Central interface for performing OpenCC-based conversion with segmentation.

Enums

OpenccConfig

OpenCC conversion configuration (strongly-typed).

Functions

find_max_utf8_len_bytes

Finds a safe UTF-8 boundary within a raw byte slice, limited by a maximum byte count.

find_max_utf8_length

Finds a valid UTF-8 boundary within the given string, limited by a maximum byte count.

for_each_len_dec

Iterates viable phrase lengths in descending order using a starter bitmask, stopping early if the callback returns true.

is_delimiter

Checks whether a character is treated as a segmentation delimiter.