MeenyLaTeX

Parse and render a subset of LaTeX to Html, and export it to standard LaTeX. This is the MiniLaTeX compiler used by Scripta.

The package exposes one module, MiniLatex.API.

Rendering

import MiniLatex.API as API

-- One shot: parse and render.
view source =
    Html.div [] (API.render source)

-- Interactive editing: parse once, keep the Data in your model,
-- and update it as the source changes. Only changed paragraphs
-- are re-parsed.
init source =
    { data = API.parse source }

update newSource model =
    { model | data = API.update newSource model.data }

view model =
    Html.div [] (API.renderData model.data)

The rendered Html produces messages of type API.LaTeXMsg (a paragraph was clicked); use Html.map to fit them into your own Msg.

Each rendered paragraph carries data-line / data-lines attributes (its source line range), for editor ↔ preview synchronization.

Table of contents

API.tableOfContents data lists the numbered headings (\section, \subsection, \subsubsection) in order. Each entry has a level (1–3), a number such as "2.1", a title, and the id of the rendered heading, for links and scrolling:

viewToc data =
    Html.ul []
        (API.tableOfContents data
            |> List.map
                (\entry ->
                    Html.li []
                        [ Html.a [ Html.Attributes.href ("#" ++ entry.id) ]
                            [ Html.text (entry.number ++ " " ++ entry.title) ]
                        ]
                )
        )

Export to LaTeX

• API.toLaTeX source is a complete standard LaTeX document, with preamble, ready for xelatex.
• API.toLaTeXBody source is the body only, without the preamble.
• API.images source lists the document's images. The exported LaTeX refers to each one as image/<filename>; download each url to that path before compiling.

Math

Math is emitted as <math-text> custom elements, which the host page must define. Without them, math source is not typeset. The example's assets/math-text.js defines math-text with KaTeX: load KaTeX's script and stylesheet, then that file.

CSS variables

The rendered Html takes two spacing values from CSS variables, so the host page can match them to its own typography:

Each has a fallback, the default above, so the output is laid out sensibly without any setup. To change them, define them on an ancestor of the rendered Html, for example:

:root {
  --paragraph-spacing: 1em;
  --indent: 2em;
}

Example

example/ is a small app that renders a sample document through MiniLatex.API. See its README for how to build and run it.

Development

The source of truth is the vendored copy in the Scripta app (scripta-app-v4/frontend/minilatex/ and its MiniLaTeX tests). Changes are made and tested there, then copied here with scripts/sync-meenylatex.sh in that repository and published from this directory. Don't edit src/ or tests/ here directly: the next sync overwrites them.

elm make --docs=docs.json   # build and check documentation
elm-test                    # run the tests (elm-test 0.19.2-0 for elm 0.19.2)