i18n: Hebrew on one line, its sign held left, CLDR's short years

gpui 0.2.2 wraps shaped glyphs in the order they are drawn, so a
right-to-left line that wraps comes out garbled. The demo's Hebrew
lines are Ellipses, which cut by characters, and an Ellipsis now sits
by its text's alignment, so a short line under text_right lies at the
right; the editor's completion details take the side they ask for. A
right-to-left locale leads a minus with a left-to-right mark, as CLDR
does, so the sign stays at the digits' left inside Hebrew. en-US and
de-DE write CLDR's two-digit year. The repeated-key and second-catalog
guards have tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -190,7 +190,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - A pane the window's blur shows through is `shell::Vibrancy`, filled with the palette's `glass`, in a window opened `WindowBackgroundAppearance::Blurred`: vibrancy on macOS, acrylic on Windows. gpui 0.2.2 has no Mica.
 - The chart's hues go by `theme::HUE_NAMES`, for an event's color and a label's alike.
 - Text whose every character counts, encoded data and keys, goes through `typography::literal`: JetBrains Mono draws `==` and `->` as ligatures (`devtools::Encoder`).
-- Messages go through `i18n::I18n`, a global the app sets: `cx.global::<I18n>().text(key, args)` fills each `{name}`. Every catalog holds the first one's keys; a missing key, argument or catalog fails. A right-to-left locale mirrors a stack with `Direction::row` and sets its text with `Direction::align`; CoreText orders mixed Hebrew and Latin runs on macOS.
+- Messages go through `i18n::I18n`, a global the app sets: `cx.global::<I18n>().text(key, args)` fills each `{name}`. Every catalog holds the first one's keys; a missing key, argument or catalog fails. A right-to-left locale mirrors a stack with `Direction::row` and sets its text with `Direction::align`; CoreText orders mixed Hebrew and Latin runs on macOS. gpui 0.2.2 wraps shaped glyphs in the order they are drawn, so a right-to-left line that wraps comes out garbled: right-to-left text stays on one line, an `Ellipsis`, which cuts by characters and sits by its text's alignment.
 
 ## Decisions
 

examples/gallery/pages/i18n/mod.rs

@@ -3,6 +3,7 @@ use ely_gpui_component::{
     i18n::{I18n, LOCALES},
     primitives::{Icon, IconName},
     theme::{ActiveTheme, Radius},
+    typography::Ellipsis,
 };
 use gpui::{AnyElement, App, IntoElement, ParentElement, Styled, Window, div, px};
 use jiff::{Timestamp, tz::TimeZone};
@@ -147,7 +148,7 @@ fn messages(cx: &App) -> impl IntoElement + use<> {
                         .flex()
                         .flex_col()
                         .gap_1()
-                        .children(lines.map(|line| div().child(line))),
+                        .children(lines.map(Ellipsis::new)),
                 ),
                 cx,
             )),
@@ -190,7 +191,7 @@ fn mirrored(cx: &App) -> impl IntoElement + use<> {
             .px_3()
             .py_2()
             .child(Icon::new(IconName::File).color(theme.colors.fg_muted))
-            .child(direction.align(div().flex_1().min_w_0().child(name)))
+            .child(direction.align(div().flex_1().min_w_0().child(Ellipsis::new(name))))
             .child(
                 div()
                     .flex_none()

src/i18n/locale.rs

@@ -61,7 +61,7 @@ pub const LOCALES: [Locale; 7] = [
         "en-US",
         "English (US)",
         (',', '.'),
-        "%-m/%-d/%Y",
+        "%-m/%-d/%y",
         Direction::Ltr,
     ),
     locale(
@@ -71,7 +71,7 @@ pub const LOCALES: [Locale; 7] = [
         "%d/%m/%Y",
         Direction::Ltr,
     ),
-    locale("de-DE", "Deutsch", ('.', ','), "%d.%m.%Y", Direction::Ltr),
+    locale("de-DE", "Deutsch", ('.', ','), "%d.%m.%y", Direction::Ltr),
     locale(
         "fr-FR",
         "Français",
@@ -93,9 +93,13 @@ impl Locale {
             .unwrap_or_else(|| panic!("no locale {tag:?}"))
     }
 
-    /// `value` with this locale's separators.
+    /// `value` with this locale's separators; a right-to-left locale leads its sign with a left-to-right mark, as CLDR does.
     pub fn number(self, value: f64, decimals: usize) -> String {
-        format::number(value, decimals, self.separators)
+        let number = format::number(value, decimals, self.separators);
+        match (self.direction, number.starts_with(format::MINUS)) {
+            (Direction::Rtl, true) => format!("\u{200e}{number}"),
+            _ => number,
+        }
     }
 
     /// The day `at` falls on in `zone`, written as this locale writes dates.

src/i18n/tests.rs

@@ -53,6 +53,20 @@ fn a_catalog_with_a_stray_key_fails() {
         .catalog("de-DE", &[("hi", "Hallo"), ("bye", "Tschüss")]);
 }
 
+#[test]
+#[should_panic(expected = "en-US repeats a key")]
+fn a_repeated_key_fails() {
+    I18n::new("en-US").catalog("en-US", &[("hi", "Hello"), ("hi", "Hey")]);
+}
+
+#[test]
+#[should_panic(expected = "en-US has a catalog")]
+fn a_second_catalog_for_a_locale_fails() {
+    I18n::new("en-US")
+        .catalog("en-US", &[("hi", "Hello")])
+        .catalog("en-US", &[("hi", "Hey")]);
+}
+
 #[test]
 #[should_panic(expected = "no locale \"xx-XX\"")]
 fn an_unlisted_locale_fails() {
@@ -76,9 +90,9 @@ fn locales_write_their_own_numbers_and_dates() {
     assert_eq!(
         cases,
         [
-            ("en-US", "−1,234,567.89".into(), "9/1/2026".into()),
+            ("en-US", "−1,234,567.89".into(), "9/1/26".into()),
             ("en-GB", "−1,234,567.89".into(), "01/09/2026".into()),
-            ("de-DE", "−1.234.567,89".into(), "01.09.2026".into()),
+            ("de-DE", "−1.234.567,89".into(), "01.09.26".into()),
             (
                 "fr-FR",
                 "−1\u{202f}234\u{202f}567,89".into(),
@@ -86,7 +100,7 @@ fn locales_write_their_own_numbers_and_dates() {
             ),
             ("ja-JP", "−1,234,567.89".into(), "2026/09/01".into()),
             ("zh-CN", "−1,234,567.89".into(), "2026/9/1".into()),
-            ("he-IL", "−1,234,567.89".into(), "1.9.2026".into()),
+            ("he-IL", "\u{200e}−1,234,567.89".into(), "1.9.2026".into()),
         ]
     );
     let rtl: Vec<_> = LOCALES
@@ -94,6 +108,11 @@ fn locales_write_their_own_numbers_and_dates() {
         .filter(|locale| locale.direction == Direction::Rtl)
         .collect();
     assert_eq!(rtl, [&Locale::of("he-IL")]);
+    assert_eq!(
+        Locale::of("he-IL").number(3.5, 1),
+        "3.5",
+        "a gain takes no mark"
+    );
 }
 
 #[cfg(feature = "test-support")]

src/typography/fit.rs

@@ -1,7 +1,7 @@
 use gpui::{
     App, Div, ElementId, InteractiveElement, IntoElement, ParentElement, Pixels, RenderOnce,
-    ShapedLine, SharedString, StatefulInteractiveElement, Styled, TextRun, Window, canvas, div,
+    ShapedLine, SharedString, StatefulInteractiveElement, Styled, TextAlign, TextRun, Window,
-    prelude::*, relative, transparent_black,
+    canvas, div, point, prelude::*, relative, transparent_black,
 };
 
 use crate::{
@@ -101,7 +101,17 @@ fn fit_end(text: &str, width: Pixels, window: &mut Window) -> String {
     cut(low)
 }
 
-/// One line in the text style around it, cut by `fit` to its box. gpui 0.2.2 keeps a line's first measure, so its own `truncate` clips instead in flex boxes.
+/// Where a line starts in a box with `free` width to spare.
+fn offset(align: TextAlign, free: Pixels) -> Pixels {
+    let free = free.max(Pixels::ZERO);
+    match align {
+        TextAlign::Left => Pixels::ZERO,
+        TextAlign::Center => free / 2.,
+        TextAlign::Right => free,
+    }
+}
+
+/// One line in the text style around it, cut by `fit` to its box and set by its alignment. gpui 0.2.2 keeps a line's first measure, so its own `truncate` clips instead in flex boxes.
 fn cut_line(text: SharedString, fit: fn(&str, Pixels, &mut Window) -> String) -> Div {
     let line = text.clone();
     div()
@@ -114,9 +124,11 @@ fn cut_line(text: SharedString, fit: fn(&str, Pixels, &mut Window) -> String) ->
             canvas(
                 move |bounds, window, _| shape(&fit(&line, bounds.size.width, window), window),
                 |bounds, shaped, window, cx| {
-                    let line = window.text_style().line_height_in_pixels(window.rem_size());
+                    let style = window.text_style();
+                    let line = style.line_height_in_pixels(window.rem_size());
+                    let x = offset(style.text_align, bounds.size.width - shaped.width);
                     shaped
-                        .paint(bounds.origin, line, window, cx)
+                        .paint(bounds.origin + point(x, Pixels::ZERO), line, window, cx)
                         .expect("a cut line paints");
                 },
             )
@@ -224,7 +236,21 @@ impl RenderOnce for EllipsisTooltip {
 
 #[cfg(test)]
 mod tests {
-    use super::elide;
+    use gpui::{TextAlign, px};
+
+    use super::{elide, offset};
+
+    #[test]
+    fn a_line_starts_by_its_alignment() {
+        assert_eq!(offset(TextAlign::Left, px(40.)), px(0.));
+        assert_eq!(offset(TextAlign::Center, px(40.)), px(20.));
+        assert_eq!(offset(TextAlign::Right, px(40.)), px(40.));
+        assert_eq!(
+            offset(TextAlign::Right, px(-8.)),
+            px(0.),
+            "a cut line fills its box"
+        );
+    }
 
     #[test]
     fn elide_keeps_both_ends() {

tasks/ch31-43.md

@@ -275,8 +275,8 @@
 
 - [x] I18nProvider → `i18n::I18n`, a gpui global: the shown locale and one catalog per locale
 - [x] Trans / LocalizedText → `I18n::text`, a message with its `{name}` arguments filled
-- [x] LocaleNumber / LocaleDate → `Locale::number` and `Locale::date`, CLDR's separators and short dates
+- [x] LocaleNumber / LocaleDate → `Locale::number` and `Locale::date`, CLDR's separators, right-to-left sign and short dates
-- [x] RTL layout — proven: `Direction::row` mirrors a stack and `Direction::align` sets its text's side; Ely's other components stay left to right
+- [x] RTL layout — proven: `Direction::row` mirrors a stack and `Direction::align` sets its text's side; a right-to-left line stays one `Ellipsis`, since gpui wraps glyphs in drawn order; Ely's other components stay left to right
 
 ## T40b a11y — `src/i18n`