#typst.mbt

A port of the Typst typesetting engine to MoonBit. See PLAN.md for scope, architecture and status.

#Layout

Path	Contents
syntax/	Port of typst-syntax: lexer, parser, syntax nodes, spans, Lines, paths and file ids (path.rs), packages and manifests (package.rs)
syntax/ast/	Typed AST over the syntax tree (ast.rs)
unicode/	Unicode property tables generated from the Rust crates upstream uses
codecs/	Image codecs upstream gets from crates: PNG decode/encode (png, fdeflate), JPEG/GIF/WebP headers (zune-jpeg, gif, image-webp), EXIF (kamadak-exif), inflate
svg/	Port of typst-svg (so far: WebImage data URLs)
oracle/	Rust crate dumping upstream reference outputs (goldens)
tests/runner/	Differential runner comparing the port against the goldens
kit/, kit/platform/	Port of typst-kit (files, packages, fonts, diagnostics) and OS access for native and wasm
cli/	Port of typst-cli: the typst command line
typst_assets/fonts/	The fonts embedded into the CLI (generated)
scripts/	upstream.sh (pinned checkout), goldens.sh (regenerate goldens)

#Command-line interface

cli/ is a port of typst-cli (on kit/, a port of typst-kit) that compiles documents from the file system. It builds for native, wasm-gc and wasm (the wasm builds run in moonrun):

moon run cli --target native --release -- compile input.typ output.pdf
moon run cli --target wasm-gc -- compile input.typ 'page-{p}.svg'
moon run cli --target native -- compile --format html --features html in.typ
moon run cli --target native -- eval 'query(heading).len()' --in input.typ
moon run cli --target native -- fonts --variants

Supported: compile/c (PDF, PNG, SVG, HTML, bundle; --root, --input, --font-path, --ignore-system-fonts, --ignore-embedded-fonts, --pages, --ppi, --pretty, --pdf-standard, --pdf-tagged, --creation-timestamp/SOURCE_DATE_EPOCH, --features, --deps, --diagnostic-format, - for stdin/stdout), eval, query, fonts, info, init (templates from local package directories) and the environment variables of upstream. Packages are served from the package data (@local, …) and cache directories; downloading packages from Typst Universe, watch, update, completions, --open and --timings are not supported. The embedded fonts are those of upstream (Libertinus Serif, New Computer Modern, DejaVu Sans Mono). On wasm, system font discovery reads every font file through moonrun's host API (slow; use --ignore-system-fonts), symlinks cannot be detected, the local time zone is UTC and only text can be written to stdout.

#Documents as MoonBit code (experimental)

The doc package builds documents with typed MoonBit constructors and compiles them with the same engine, without Typst markup. The API is experimental and may change between releases; the design is in docs/edsl-design.md.

fn report() -> @doc.Document {
  @doc.Document([
    @doc.SetPage(paper="a5", margin=@doc.Sides(all=@doc.Cm(1.8))),
    @doc.SetHeading(numbering=@doc.Numbering("1.")),
    @doc.Heading("Build times"),
    (
      $|Running text is a multiline string; inline elements such as
      $|\{@doc.Emph("emphasis")} and \{@doc.Raw("code")} are interpolated.
    )
    |> @doc.Prose,
    @doc.Equation("sum_(k=1)^n k = (n(n+1))/2", block=true),
  ])
}

fn run() -> Unit raise {
  let world = @system.world(root=".", system_fonts=false, today=(2026, 10, 5))
  let compiled = report().compile_paged(world)
  @system.write("report.pdf", compiled.pdf().unwrap())
}

Import moonbitlang/typst/doc and moonbitlang/typst/doc/system (file and font access). Plain strings are literal text and are never parsed as markup; Markup(..) and Equation(..) are the explicit escape hatches.

#Testing

scripts/upstream.sh            # checkout upstream at UPSTREAM_REV
scripts/goldens.sh             # needs Rust; or `scripts/goldens.sh syntax ast`
moon run tests/runner --target native -- syntax [filter] [-v]
moon run tests/runner --target native -- ast [filter] [-v]

Site source Report issue Packages Build queue Skills Statistics