meco-core

meco-core is the pure-by-default Rust engine for the Mongolian Encoding Converter. It supports Zvvnmod, Delehi, MenkShape, MenkLetter, and Z52; conversions route through the Zvvnmod hub. The minimum supported Rust version is 1.82.

Basic use

use meco_core::{translate, CodeType};

let input = "\u{E0E5}";
let output = translate(CodeType::MenkShape, CodeType::Zvvnmod, input)
    .expect("ZVVNMOD conversion should succeed");

Optional UTN #57 output

Canonical UTN #57 Unicode output is available through the same API with the explicit utn57-command feature:

[dependencies]
meco-core = { version = "0.2.0", features = ["utn57-command"] }

use meco_core::{translate, CodeType};

let input = "\u{E0E5}";
let output = translate(CodeType::MenkShape, CodeType::Utn57, input)
    .expect("UTN #57 conversion should succeed");

The feature adds the command-backed zvvnmod-utn57 integration but does not install Python or run a downloader during the Cargo build. A server or desktop deployment that converts formal ZVVNMOD shapes must install the reviewed backend explicitly:

cargo install zvvnmod-utn57 --version 0.1.0-alpha.3 --locked
zvvnmod-install-mongol-norm

Without the feature, a non-identity conversion targeting CodeType::Utn57 returns MecoError::Unsupported(CodeType::Utn57). With the feature enabled, an unavailable or failing backend returns MecoError::Utn57(reason). Reverse conversion from UTN #57 remains unsupported. Identity and blank-input conversions retain the normal short-circuit behavior and do not start the backend.

The optional conversion path is:

source encoding
→ meco-core ZVVNMOD hub
→ zvvnmod-utn57 0.1.0-alpha.3
→ explicitly installed mongol-norm command
→ canonical Unicode

For bindings, distribution, and the Java-oracle verification details, see the meco-rust repository.