mdi-core

mdi-core is the native Rust implementation of illusion Markdown (MDI), a Markdown extension for Japanese typography. It parses CommonMark, GFM, YAML front matter, and MDI syntax into a portable document tree, and provides deterministic HTML, text, EPUB, DOCX, and PDF renderers.

Install

[dependencies]
mdi-core = "2.0"

Quick start

use mdi_core::{parse_document, render_html};

let source = "第^12^話。{東京|とうきょう}は雨だった。";

let document = parse_document(source);
assert_eq!(document.children.len(), 1);

let html = render_html(source);

Use parse_output when you also need parser capabilities and diagnostics. Use get_mdi_text_blocks when a search or annotation index needs source-order plaintext blocks with one-based Unicode-grapheme coordinates and exact UTF-8 source maps. The result includes the same document IR and diagnostics, and the source is parsed only once. Use resolve_mdi_source_span for the inverse lookup: a validated half-open UTF-8 source span becomes ordered canonical block-text and ruby-annotation ranges. Its complete, partial, or none coverage reports whether every requested source byte belongs to at least one mapped grapheme; synthetic and unmapped projection text never creates a match. For diagnostics or decoration batches, use resolve_mdi_source_spans; it validates every span first, then parses and projects the source exactly once and returns resolutions in input order. When rendering one parsed document in multiple formats, use the *_document functions, such as render_html_document, to avoid parsing it again.

Publication profiles are also resolved in Rust. Use render_epub_with_profile or render_docx_with_profile when you need metadata, typography, chapter splitting, cover art, page geometry, or page numbers. page_size_catalog_json exposes the same 67 paper definitions to bindings and user interfaces, so other languages do not need to copy the dimension table.

Documentation

License

MIT. See LICENSE.

Automatic warichu presentation layout

The Rust core supplies two lines at 50% body size with no line gap. Capacity is measured in half-em units at the note font size; it is a character-width estimate, not exact proportional-font measurement. The first fragment can use the space remaining on the current body line; following fragments use the full capacity.

let nodes = serde_json::json!([{"type":"text", "value":"一二三四五六"}]);
let fragments = mdi_core::layout_warichu_with_options(nodes.as_array().unwrap(),
    &mdi_core::WarichuOptions { first_capacity: 2, continuation_capacity: 4 });
assert_eq!(fragments.len(), 2);

Results contain lines, html, widths, overflow, hardBreakAfter, and sources. Each source has a child-index path relative to the input inline array, half-open startUtf8 / endUtf8 offsets into that leaf's visible text, and an indivisible group ID. A cluster crossing formatting boundaries shares a group. Ruby, tcy, no-break and unknown containers remain whole; their coordinates use projected visible text (ruby base, excluding its reading). Oversized groups remain available and report overflow. Author hard breaks are retained; automatic splits never enter canonical MDI or plain text.