Crate inputx_nihongo 

Japanese input engine — pluggable third-source for Inputx.

Scope (v0.1)

• Romaji → hiragana / katakana conversion (Hepburn primary, kunrei alternates accepted). Whole-buffer rendering: every keystroke re-renders the kana from scratch.
• Single-kanji lookup by on-yomi: when the user’s romaji buffer is exactly a valid on-yomi reading (e.g. ka, kou), surface the kanji that read that way — restricted to kanji whose Unicode codepoint is identical to a Simplified-Chinese hanzi (the codepoint- identity check is baked into kanji::KANJI_TABLE; new entries must be hand-verified before adding).

Not in v0.1

• Compound conversion (e.g. nihon → 日本) — the engine produces hiragana/katakana for multi-syllable input but does not assemble kanji compounds.
• okurigana / verb inflection
• User-learning / pin / freq-tuning
• Per-kanji frequency ordering — candidates are returned in declaration order from KANJI_TABLE.

Plugin-style integration

This crate is self-contained — no dependency on inputx-wubi / inputx-pinyin. The consumer (typically inputx-core::composite) holds an optional JapaneseEngine and routes keystrokes to it based on the enable_japanese flag. When disabled the engine is never constructed and JP has zero runtime cost on the hot path.

See engine::JapaneseEngine for the main entry point.

Re-exports

pub use engine::Candidate;

pub use engine::JapaneseEngine;

pub use engine::KanaKind;

Modules

engine

JP engine state machine — parallel in shape to inputx-wubi’s WubiEngine and inputx-pinyin’s segmenter so the composite layer can plug it in next to the existing engines without bespoke wiring.

jukugo

Jukugo (熟語) table — JP compound words with reading + freq.

kanji

Kanji table — JP kanji with on/kun readings + relative frequency.

romaji

Romaji → kana conversion. Hepburn primary; kunrei alternates accepted so users can type si/ti/tu/hu/zi and get the canonical kana.