Write (export): a standalone LaTeX 2ε article that compiles with pdfLaTeX, XeLaTeX or LuaLaTeX using only packages every distribution ships (fontenc, ulem, xcolor, multirow, amsmath, hyperref): unnumbered sectioning commands, itemize/enumerate, tabular with the column widths, equations $…$ / \[…\], character formatting, links and bookmarks. Pictures become their alternative text. Nothing the document says is written as a TeX command.
Read (import, parse for the flow): the everyday subset documents are written in: the preamble's \title/\author, sectioning, paragraphs, lists, quote, center/flush…, verbatim-like environments, tabular with \multicolumn/\multirow, inline and display math (kept as equations), text formatting commands and declarations, colours, links, labels, accents, special characters and ligatures. It is not a TeX engine: macros are not expanded. Unknown commands are dropped with their braced arguments kept as text; layout commands are dropped with their arguments. Bytes that name no encoding are decoded by craft_mime::detect.

let doc = craft_latex::import(br"\section*{Intro} Some \textbf{bold} text and $x^2$.");
assert!(doc.plain_text(Default::default()).starts_with("Intro\nSome bold text and"));
let tex = craft_latex::export(&doc);
assert!(tex.contains(r"\section*{Intro}") && tex.contains(r"\textbf{bold}") && tex.contains("$x^2$"));

Input is hostile: nesting, column specs, labels and the source size (MAX_SOURCE) are bounded, and the work is linear.

Math

A document's math is converted to and from the linear format equations are kept in by craft_math::latex_text (re-exported here as latex_to_linear and linear_to_latex), which works on the text and keeps the source's spacing.

Moved from WordCraft (crates/formats/src/latex, 07f97737) with its tests and the LaTeX parts of its cross-format tests.