chore: update vendored libghostty-vt

refs #276

1 files changed, 53 insertions, 0 deletions

diff --git a/vendor/libghostty-vt/src/unicode/main.zig b/vendor/libghostty-vt/src/unicode/main.zig
index 11ecbd90..fb18b7d1 100644
--- a/vendor/libghostty-vt/src/unicode/main.zig
+++ b/vendor/libghostty-vt/src/unicode/main.zig
@@ -3,7 +3,60 @@ pub const lut = @import("lut.zig");
 const grapheme = @import("grapheme.zig");
 pub const table = @import("props_table.zig").table;
 pub const Properties = @import("props.zig").Properties;
+pub const GraphemeWidthEffect = grapheme.GraphemeWidthEffect;
+pub const GraphemeWidth = grapheme.GraphemeWidth;
 pub const graphemeBreak = grapheme.graphemeBreak;
+pub const graphemeWidth = grapheme.graphemeWidth;
+pub const graphemeWidthEffect = grapheme.graphemeWidthEffect;
+
+/// Returns the terminal display width of a codepoint in terminal
+/// grid cells: 0, 1, or 2.
+///
+/// This is the same width table the terminal uses when laying out
+/// printed text: 0 for zero-width codepoints (controls, combining
+/// marks, default-ignorables, surrogates), 2 for wide codepoints
+/// (East Asian Wide/Fullwidth, regional indicators, clamped at 2),
+/// and 1 otherwise.
+///
+/// This operates on a single codepoint and cannot account for
+/// grapheme-cluster-level width rules (VS16, combining sequences);
+/// callers needing cluster-accurate widths should use graphemeWidth().
+/// Summing per-codepoint widths is only correct when mode 2027 is
+/// disabled.
+pub fn codepointWidth(cp: u21) u2 {
+    return table.get(cp).width;
+}
+
+test "codepointWidth" {
+    const testing = @import("std").testing;
+
+    // Narrow (width 1)
+    try testing.expectEqual(1, codepointWidth('a'));
+    try testing.expectEqual(1, codepointWidth(' '));
+    try testing.expectEqual(1, codepointWidth(0x10FFFF)); // max codepoint
+
+    // C0/C1 control characters (width 0)
+    try testing.expectEqual(0, codepointWidth(0x00)); // NUL
+    try testing.expectEqual(0, codepointWidth(0x07)); // BEL
+    try testing.expectEqual(0, codepointWidth(0x1B)); // ESC
+    try testing.expectEqual(0, codepointWidth(0x7F)); // DEL
+    try testing.expectEqual(0, codepointWidth(0x80)); // C1 PAD
+
+    // Zero-width codepoints
+    try testing.expectEqual(0, codepointWidth(0x0301)); // combining acute
+    try testing.expectEqual(0, codepointWidth(0x200B)); // zero width space
+    try testing.expectEqual(0, codepointWidth(0x200D)); // ZWJ
+    try testing.expectEqual(0, codepointWidth(0xFE0F)); // VS16
+    try testing.expectEqual(0, codepointWidth(0xD800)); // surrogate
+
+    // Wide (width 2)
+    try testing.expectEqual(2, codepointWidth(0x4E00)); // CJK ideograph
+    try testing.expectEqual(2, codepointWidth(0xFF21)); // fullwidth A
+    try testing.expectEqual(2, codepointWidth(0xAC00)); // Hangul syllable
+    try testing.expectEqual(2, codepointWidth(0x1F600)); // emoji
+    try testing.expectEqual(2, codepointWidth(0x1F1E6)); // regional indicator
+    try testing.expectEqual(2, codepointWidth(0x2E3B)); // three-em dash (clamped)
+}
 
 test {
     @import("std").testing.refAllDecls(@This());