3 files changed, 97 insertions, 84 deletions

diff --git a/src/Grapheme.zig b/src/Grapheme.zig
index 6892a2a..910aec5 100644
--- a/src/Grapheme.zig
+++ b/src/Grapheme.zig
@@ -56,7 +56,7 @@ pub const GraphemeIterator = struct {
 
         const gc_start = self.buf[0].?.offset;
         var gc_len: usize = self.buf[0].?.len;
-        var state: u3 = 0;
+        var state = State{};
 
         if (graphemeBreak(
             self.buf[0].?.code,
@@ -95,36 +95,42 @@ fn isIgnorable(cp: u21) bool {
 }
 
 // Grapheme break state.
-// Extended Pictographic (emoji)
-fn hasXpic(state: *const u3) bool {
-    return state.* & 1 == 1;
-}
-fn setXpic(state: *u3) void {
-    state.* |= 1;
-}
-fn unsetXpic(state: *u3) void {
-    state.* ^= 1;
-}
-// Regional Indicatior (flags)
-fn hasRegional(state: *const u3) bool {
-    return state.* & 2 == 2;
-}
-fn setRegional(state: *u3) void {
-    state.* |= 2;
-}
-fn unsetRegional(state: *u3) void {
-    state.* ^= 2;
-}
-// Indic Conjunct
-fn hasIndic(state: *const u3) bool {
-    return state.* & 4 == 4;
-}
-fn setIndic(state: *u3) void {
-    state.* |= 4;
-}
-fn unsetIndic(state: *u3) void {
-    state.* ^= 4;
-}
+const State = struct {
+    bits: u3 = 0,
+
+    // Extended Pictographic (emoji)
+    fn hasXpic(self: State) bool {
+        return self.bits & 1 == 1;
+    }
+    fn setXpic(self: *State) void {
+        self.bits |= 1;
+    }
+    fn unsetXpic(self: *State) void {
+        self.bits ^= 1;
+    }
+
+    // Regional Indicatior (flags)
+    fn hasRegional(self: State) bool {
+        return self.bits & 2 == 2;
+    }
+    fn setRegional(self: *State) void {
+        self.bits |= 2;
+    }
+    fn unsetRegional(self: *State) void {
+        self.bits ^= 2;
+    }
+
+    // Indic Conjunct
+    fn hasIndic(self: State) bool {
+        return self.bits & 4 == 4;
+    }
+    fn setIndic(self: *State) void {
+        self.bits |= 4;
+    }
+    fn unsetIndic(self: *State) void {
+        self.bits ^= 4;
+    }
+};
 
 /// `graphemeBreak` returns true only if a grapheme break point is required
 /// between `cp1` and `cp2`. `state` should start out as 0. If calling
@@ -135,7 +141,7 @@ fn unsetIndic(state: *u3) void {
 pub fn graphemeBreak(
     cp1: u21,
     cp2: u21,
-    state: *u3,
+    state: *State,
 ) bool {
     // Extract relevant properties.
     const cp1_props_byte = gbp.stage_3[gbp.stage_2[gbp.stage_1[cp1 >> 8] + (cp1 & 0xff)]];
@@ -149,9 +155,9 @@ pub fn graphemeBreak(
     const cp2_is_emoji = cp2_props_byte & 1 == 1;
 
     // GB11: Emoji Extend* ZWJ x Emoji
-    if (!hasXpic(state) and cp1_is_emoji) setXpic(state);
+    if (!state.hasXpic() and cp1_is_emoji) state.setXpic();
     // GB9c: Indic Conjunct Break
-    if (!hasIndic(state) and cp1_indic_prop == .Consonant) setIndic(state);
+    if (!state.hasIndic() and cp1_indic_prop == .Consonant) state.setIndic();
 
     // GB3: CR x LF
     if (cp1 == '\r' and cp2 == '\n') return false;
@@ -159,23 +165,13 @@ pub fn graphemeBreak(
     // GB4: Control
     if (isBreaker(cp1)) return true;
 
-    // GB6: Hangul L x (L|V|LV|VT)
-    if (cp1_gbp_prop == .L) {
-        if (cp2_gbp_prop == .L or
-            cp2_gbp_prop == .V or
-            cp2_gbp_prop == .LV or
-            cp2_gbp_prop == .LVT) return false;
-    }
-
-    // GB7: Hangul (LV | V) x (V | T)
-    if (cp1_gbp_prop == .LV or cp1_gbp_prop == .V) {
-        if (cp2_gbp_prop == .V or
-            cp2_gbp_prop == .T) return false;
-    }
-
-    // GB8: Hangul (LVT | T) x T
-    if (cp1_gbp_prop == .LVT or cp1_gbp_prop == .T) {
-        if (cp2_gbp_prop == .T) return false;
+    // GB11: Emoji Extend* ZWJ x Emoji
+    if (state.hasXpic() and
+        cp1_gbp_prop == .ZWJ and
+        cp2_is_emoji)
+    {
+        state.unsetXpic();
+        return false;
     }
 
     // GB9b: x (Extend | ZWJ)
@@ -189,44 +185,54 @@ pub fn graphemeBreak(
 
     // GB12, GB13: RI x RI
     if (cp1_gbp_prop == .Regional_Indicator and cp2_gbp_prop == .Regional_Indicator) {
-        if (hasRegional(state)) {
-            unsetRegional(state);
+        if (state.hasRegional()) {
+            state.unsetRegional();
             return true;
         } else {
-            setRegional(state);
+            state.setRegional();
             return false;
         }
     }
 
-    // GB11: Emoji Extend* ZWJ x Emoji
-    if (hasXpic(state) and
-        cp1_gbp_prop == .ZWJ and
-        cp2_is_emoji)
-    {
-        unsetXpic(state);
-        return false;
+    // GB6: Hangul L x (L|V|LV|VT)
+    if (cp1_gbp_prop == .L) {
+        if (cp2_gbp_prop == .L or
+            cp2_gbp_prop == .V or
+            cp2_gbp_prop == .LV or
+            cp2_gbp_prop == .LVT) return false;
+    }
+
+    // GB7: Hangul (LV | V) x (V | T)
+    if (cp1_gbp_prop == .LV or cp1_gbp_prop == .V) {
+        if (cp2_gbp_prop == .V or
+            cp2_gbp_prop == .T) return false;
+    }
+
+    // GB8: Hangul (LVT | T) x T
+    if (cp1_gbp_prop == .LVT or cp1_gbp_prop == .T) {
+        if (cp2_gbp_prop == .T) return false;
     }
 
     // GB9c: Indic Conjunct Break
-    if (hasIndic(state) and
+    if (state.hasIndic() and
         cp1_indic_prop == .Consonant and
         (cp2_indic_prop == .Extend or cp2_indic_prop == .Linker))
     {
         return false;
     }
 
-    if (hasIndic(state) and
+    if (state.hasIndic() and
         cp1_indic_prop == .Extend and
         cp2_indic_prop == .Linker)
     {
         return false;
     }
 
-    if (hasIndic(state) and
+    if (state.hasIndic() and
         (cp1_indic_prop == .Linker or cp1_gbp_prop == .ZWJ) and
         cp2_indic_prop == .Consonant)
     {
-        unsetIndic(state);
+        state.unsetIndic();
         return false;
     }
 
diff --git a/src/display_width.zig b/src/display_width.zig
index aed0ef1..2ac7093 100644
--- a/src/display_width.zig
+++ b/src/display_width.zig
@@ -42,17 +42,10 @@ fn isAsciiOnly(str: []const u8) bool {
 pub fn strWidth(str: []const u8) usize {
     var total: isize = 0;
 
+    // ASCII fast path
     if (isAsciiOnly(str)) {
-        for (str) |b| {
-            // Backspace and delete
-            if (b == 0x8 or b == 0x7f) {
-                total -= 1;
-            } else if (b >= 0x20) {
-                total += 1;
-            }
-        }
-
-        return if (total > 0) @intCast(total) else 0;
+        for (str) |b| total += codePointWidth(b);
+        return @intCast(@max(0, total));
     }
 
     var giter = GraphemeIterator.init(str);
@@ -72,14 +65,17 @@ pub fn strWidth(str: []const u8) usize {
                 }
 
                 // Only adding width of first non-zero-width code point.
-                if (gc_total == 0) gc_total = w;
+                if (gc_total == 0) {
+                    gc_total = w;
+                    break;
+                }
             }
         }
 
         total += gc_total;
     }
 
-    return if (total > 0) @intCast(total) else 0;
+    return @intCast(@max(0, total));
 }
 
 test "display_width Width" {
@@ -147,4 +143,14 @@ test "display_width Width" {
     // The following passes but as a mere coincidence.
     const kannada_2 = "\u{0cb0}\u{0cbc}\u{0ccd}\u{0c9a}";
     try testing.expectEqual(@as(usize, 2), strWidth(kannada_2));
+
+    // From Rust https://github.com/jameslanska/unicode-display-width
+    try testing.expectEqual(@as(usize, 15), strWidth("🔥🗡🍩👩🏻‍🚀⏰💃🏼🔦👍🏻"));
+    try testing.expectEqual(@as(usize, 2), strWidth("🦀"));
+    try testing.expectEqual(@as(usize, 2), strWidth("👨‍👩‍👧‍👧"));
+    try testing.expectEqual(@as(usize, 2), strWidth("👩‍🔬"));
+    try testing.expectEqual(@as(usize, 9), strWidth("sane text"));
+    try testing.expectEqual(@as(usize, 9), strWidth("Ẓ̌á̲l͔̝̞̄̑͌g̖̘̘̔̔͢͞͝o̪̔T̢̙̫̈̍͞e̬͈͕͌̏͑x̺̍ṭ̓̓ͅ"));
+    try testing.expectEqual(@as(usize, 17), strWidth("슬라바 우크라이나"));
+    try testing.expectEqual(@as(usize, 1), strWidth("\u{378}"));
 }
diff --git a/src/main.zig b/src/main.zig
index bb188ff..38ba343 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -1,12 +1,12 @@
 const std = @import("std");
 
 // const GraphemeIterator = @import("ziglyph").GraphemeIterator;
-const GraphemeIterator = @import("Grapheme").GraphemeIterator;
+// const GraphemeIterator = @import("Grapheme").GraphemeIterator;
 // const codePointWidth = @import("ziglyph").display_width.codePointWidth;
 // const codePointWidth = @import("display_width").codePointWidth;
 // const strWidth = @import("ziglyph").display_width.strWidth;
-// const strWidth = @import("display_width").strWidth;
-// const CodePointIterator = @import("CodePoint").CodePointIterator;
+const strWidth = @import("display_width").strWidth;
+const CodePointIterator = @import("CodePoint").CodePointIterator;
 
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
@@ -17,16 +17,17 @@ pub fn main() !void {
     defer allocator.free(input);
 
     var result: usize = 0;
-    var iter = GraphemeIterator.init(input);
+    // var result: isize = 0;
+    // var iter = GraphemeIterator.init(input);
     // var iter = CodePointIterator{ .bytes = input };
-    // var iter = std.mem.splitScalar(u8, input, '\n');
+    var iter = std.mem.splitScalar(u8, input, '\n');
 
     var timer = try std.time.Timer.start();
 
     // for (0..50) |_| {
     // while (iter.next()) |cp| result += codePointWidth(@intCast(cp.code));
-    while (iter.next()) |_| result += 1;
-    // while (iter.next()) |line| result += strWidth(line);
+    // while (iter.next()) |_| result += 1;
+    while (iter.next()) |line| result += strWidth(line);
     // iter.cp_iter.i = 0;
     // }