Universe

Automatic RTL/LTR direction detection for mixed-direction Typst documents.

Sets text.dir per block using the first strong character rule — the same heuristic used by most editors and the Unicode Bidi Algorithm. No manual tagging needed for most content.

Import

// Published package import
#import "@preview/bidi-flow:0.1.1": *

Quick start

#import "@preview/bidi-flow:0.1.1": *
#show: bidi-flow

= Hello        // → LTR heading
= שלום         // → RTL heading automatically

English paragraph here.

פסקה בעברית מופיעה אוטומטית מימין לשמאל.

- English list
- items here

- רשימה בעברית
- מוצגת מימין לשמאל

Example output

API

bidi-flow

Document-level show rule. Detects direction for par, heading, list, enum, and table automatically.

#show: bidi-flow

detect-dir(body)

Inspect a content block and return its detected direction (ltr or rtl). Useful for building your own show rules or templates.

let d = detect-dir(heading.body)
// d == rtl  or  d == ltr
set text(dir: d)

Fonts

Choosing fonts for multilingual documents can be tedious, so bidi-flow provides a small high-level API for script-aware font selection.

#show: bidi-flow.with(
  latin-font: "New Computer Modern",
  hebrew-font: "Noto Serif Hebrew",
  font: "Libertinus Serif",
)

In this example, Latin text uses New Computer Modern and Hebrew text uses Noto Serif Hebrew. The font argument acts as the generic fallback or base font for scripts that were not explicitly overridden and for any missing glyphs.

If you do not pass any font arguments, Typst’s default font resolution is used. Passing only font applies it as the document’s base font. When both font and script-specific overrides are present, the script-specific fonts win for their matching codepoints.

Inline spans — #rl[...] / #lr[...]

Force direction for a mixed-direction fragment:

The price is #rl[₪ 100] today.       // force RTL around the price
בסוף המשפט יש מילה #lr[inline] כך.  // force LTR inside Hebrew

Directional seeds — #r / #l

Zero-width invisible characters that seed the bidi shaping context. Useful for fixing punctuation and number alignment in mixed runs:

המחיר הוא 100 #r ₪     // nudge shekel sign to correct side

Local installation

mkdir -p ~/.local/share/typst/packages/local/bidi-flow/0.1.1
cp -r . ~/.local/share/typst/packages/local/bidi-flow/0.1.1/

Then import with @local/bidi-flow:0.1.1.

Notes

  • Requires Typst ≥ 0.14.0
  • Direction detection ignores math.equation and raw blocks
  • Works with strong, emph, link, and other inline wrappers
  • #r / #l are content values, not functions — do not call them with brackets

Changes in 0.1.1 (Non-Breaking)

  • Added optional font overrides to bidi-flow (existing usage continues to work unchanged):
    • font
    • latin-font
    • arab-font
    • hebrew-font

Repository

See original source repository