Right-to-left text

texish sets right-to-left scripts — Hebrew and Arabic — alongside left-to-right text in the same paragraph. It lays out and breaks every paragraph in logical (reading) order, exactly as TeX does, then reorders each finished line into visual order with the Unicode Bidirectional Algorithm (UAX #9) before drawing it. Numbers and embedded Latin keep their own direction, brackets are mirrored, pointed Hebrew has its niqqud positioned by the font’s anchors, and Arabic is shaped cursively — each letter connecting to its neighbours — with its vowel marks and ligatures.

Base direction

\rtl switches the paragraph base direction to right-to-left; \ltr switches it back. Like \leftskip, the setting persists until you change it, so wrap a passage in a group to scope it. Under a right-to-left base the paragraph aligns to the right margin and the last line rags to the left.

\rtl
{\font hebrew 14 regular
בראשית היה הדבר והדבר היה את האלהים ואלהים היה הדבר׃
}
\ltr

The line breaker is untouched — it still finds its breaks at the interword glue, in logical order. Only the set lines are turned into visual order, so justification, hyphenation of any embedded Latin, and page breaking all work as usual.

Margin indentation follows the reading side. Under a right-to-left base \leftskip sets the leading (right) margin and \rightskip the trailing (left) one, so an indented block, and a list built with \begin{itemize} or \begin{enumerate}, indents from the right and hangs its markers on the right.

The Hebrew font

A Hebrew face, Noto Serif Hebrew, is bundled in a regular and a bold cut. Select it with \font hebrew:

{\font hebrew 18 bold בראשית היה הדבר׃}

(As with the bundled CJK faces, the in-browser Scala.js build does not ship the Hebrew font, to keep the download small.)

Bidirectional text

A Latin word or a run of digits inside a right-to-left line keeps its own left-to-right order: the algorithm treats each as an embedded island and reverses only the Hebrew around it. Nothing special is needed — write the text in logical (reading) order and the engine resolves the rest.

\rtl
{\font hebrew 14 regular
הבשורה על־פי יוחנן פרק 1 בתרגום Delitzsch אל העברית׃
}
\ltr

A bracket or parenthesis that lands in a right-to-left context is drawn mirrored (rule L4), so parentheses around Hebrew enclose it the way a reader expects: (אב) written in logical order displays with the open and close brackets on the correct sides.

The reverse case needs no base change. A Hebrew word inside an ordinary left-to-right paragraph is reversed in place while the surrounding text is left exactly as it is:

The Hebrew word {\font hebrew 12 regular דבר} means ``word''.

Pointed text (niqqud)

Hebrew is normally written without vowels, but scripture and teaching texts add niqqud — the points set above, below and inside the letters. These are combining marks with no width of their own; texish reads the font’s GPOS anchor data to place each one on its consonant rather than letting it fall at the pen. Write the consonants and points in the usual logical order and they are positioned automatically:

\rtl
{\font hebrew 16 regular
בְּרֵאשִׁית בָּרָא אֱלֹהִים אֵת הַשָּׁמַיִם וְאֵת הָאָרֶץ׃
}
\ltr

Unpointed Hebrew needs none of this and takes the plain text path, so it costs nothing.

Some faces cut for pointed text draw a letter and the point inside it — a dagesh, a mapiq, a shin or sin dot — as a single shape rather than as a letter with a mark laid over it, and give no anchor for placing that point on its own. The bundled Ezra SIL, cut in the style of the Biblia Hebraica Stuttgartensia and selected with \font ezra, is such a face. texish combines the pair through the font’s own composition feature, so the dagesh sets inside its letter:

\rtl
{\font ezra 18 regular
בְּרֵאשִׁית בָּרָא אֱלֹהִים אֵת הַשָּׁמַיִם וְאֵת הָאָרֶץ׃
}
\ltr

Which pairs combine is the font’s decision, not the engine’s: Ezra combines a letter with its dagesh but leaves an alef and its patah to be placed by anchor, and Noto Serif Hebrew combines nothing at all. Both are set correctly without any choice on your part. The points of a syllable are put into drawing order first, so a dagesh reaches its letter even though the stored order sorts a vowel in front of it.

Arabic

Arabic is cursive: within a word the letters connect, and each takes one of four shapes — initial, medial, final or isolated — according to its neighbours. texish resolves each letter’s form in reading order (Unicode joining) and asks the font’s shaping tables for the matching glyph, so a run reads as one joined stroke rather than a row of separate signs. An Arabic face, Noto Serif–style Noto Naskh Arabic, is bundled in a regular and a bold cut; select it with \font arabic. Base direction, bidirectional islands and bracket mirroring all work exactly as for Hebrew.

\rtl
{\font arabic 14 regular
اللغة العربية تكتب من اليمين إلى اليسار، وتتصل حروفها بعضها ببعض داخل الكلمة.
}
\ltr

Two ligatures form automatically. Where a lam is followed by an alef the pair is drawn as its required lam-alef ligature rather than two separate letters. And when the text is pointed, the word for God — الله — is drawn as the single tightly-bound calligraphic ligature that traditional typography uses; unpointed, it stays as the ordinary connected letters.

Arabic vowels (harakat) are combining marks placed by the same anchor mechanism as the Hebrew points, and they stack: a vowel written over a shadda sits above it, and a vowel clears a letter’s own dots. Write the letters and marks in logical order and they are positioned automatically.

The marks of a syllable are put into drawing order before the text is shaped, following the Unicode rules for Arabic mark rendering, so the shadda is drawn on the letter with the vowel stacked above it. This is the reverse of the order the two are normally stored in — a vowel’s combining class is the lower, so normalized text puts it first — which means the typed order does not matter: a shadda typed before its vowel and one typed after it set identically. Hamza and the Qur’anic reading marks are drawn nearest the letter of all, ahead of the shadda.

\rtl
{\font arabic 16 regular
كَتَبَ الوَلَدُ. مُحَمَّد. بِسْمِ الرَّحِيم.
}
\ltr

Persian, Urdu and the other languages written in the Arabic script are shaped by the same engine; a font that covers their letters will set them.

Scope

Hebrew and Arabic — unpointed and pointed, on their own and mixed with left-to-right text — are supported on every backend. The bundled faces do not ship in the in-browser Scala.js build, to keep the download small.