# halkyon_learn_curator

Turns dictionary downloads into the dictionary files a Halkyon Learn server
loads. It reads each source with an adapter of its own and writes one format
for all of them, so a new source or language needs a new adapter, never a
change to the server or the app. It doesn't depend on Serverpod or the server.

## Making a dictionary file

JMdict in English, with the JLPT levels on top:

1. Download `jmdict-eng-<version>.json.tgz` from
   [jmdict-simplified's releases](https://github.com/scriptin/jmdict-simplified/releases)
   and unpack it.
2. Download `original_data/n1.csv` … `n5.csv` from
   [yomitan-jlpt-vocab](https://github.com/stephenmk/yomitan-jlpt-vocab) into a
   folder.
3. Convert, in this package:

   ```sh
   dart run halkyon_learn_curator:curate jmdict \
     --input jmdict-eng-3.6.2.json --jlpt jlpt/ --output jmdict-en.jsonl.gz
   ```

   The whole of JMdict (about 219,000 entries) takes some 20 seconds and
   300 MB of memory: entries are read one at a time.

Put the file into the server's `dictionaries` folder. The server loads it on
its next start, and again whenever the file changes (see the server's README).

## The format (`halkyon-dictionary`, version 1)

[JSON Lines](https://jsonlines.org/), gzipped when the name ends in `.gz`.

The **first line** says what the file holds:

| Field | |
|---|---|
| `format`, `formatVersion` | `"halkyon-dictionary"`, `1` |
| `source`, `sourceVersion` | The source's name (`jmdict`) and version (`3.6.2 (2026-10-05)`). An instance holds one version of a source for each meaning language. |
| `language`, `glossLanguage` | BCP 47 tags: the words' language (`ja`) and the meanings' (`en`). |
| `license` | The data's licence, an SPDX identifier (`CC-BY-SA-4.0`). |
| `credits` | Everything it is drawn from: `name`, `by`, `license`, `url`. The app lists them where it credits its data sources. |

**Every further line** is an entry:

| Field | |
|---|---|
| `id` | Its id in the source; with the source and meaning language, it names the entry for good. |
| `headword`, `reading` | How the word is shown, and how it is read; no `reading` when the headword is its own (a word written in kana). |
| `labels` | What it can be picked by: `common`, `jlpt:n5` … `jlpt:n1` (later e.g. `hsk:3`, `topik:1`). |
| `rank` | Its order among the source's entries, lower first; JMdict: N5 to N1 in their lists' order, then other common words, then the rest. |
| `keys` | What a search matches, lower case: written forms, readings in their own script and romanised, meanings. Everything specific to a language happens here, so the server's search knows no language. |
| `entry` | The entry itself, as cards take it: `forms` and `readings` (`text`, `common`, the source's `tags`; for a reading the `forms` it belongs to), `senses` (`glosses`; the source's codes in `pos`, `misc`, `field`, `dialect`; `info`; the `forms` and `readings` a sense is limited to). Lists are left out when empty. |

## Adding a source

Write an adapter in `lib/src/sources/` that turns the source into the lines
above, with its credits and a sample of real data in `test/fixtures/` (and
where that comes from in `test/fixtures/README.md`); give it a command in
`bin/curate.dart`. Check the source's licence first, and that the instance may
pass its data on to the people using it.