gwidth: use an iterator to prevent returning error

This is a breaking change to gwidth: we no longer return an error

src/Vaxis.zig

···
             if (cell.char.width != 0) break :blk cell.char.width;
 
             const method: gwidth.Method = self.caps.unicode;
-            const width = gwidth.gwidth(cell.char.grapheme, method, &self.unicode.width_data) catch 1;
+            const width = gwidth.gwidth(cell.char.grapheme, method, &self.unicode.width_data);
             break :blk @max(1, width);
         };
         defer {
···
             if (cell.char.width != 0) break :blk cell.char.width;
 
             const method: gwidth.Method = self.caps.unicode;
-            const width = gwidth.gwidth(cell.char.grapheme, method, &self.unicode.width_data) catch 1;
+            const width = gwidth.gwidth(cell.char.grapheme, method, &self.unicode.width_data);
             break :blk @max(1, width);
         };
         defer {

src/Window.zig

···
 
 /// returns the width of the grapheme. This depends on the terminal capabilities
 pub fn gwidth(self: Window, str: []const u8) usize {
-    return gw.gwidth(str, self.screen.width_method, &self.screen.unicode.width_data) catch 1;
+    return gw.gwidth(str, self.screen.width_method, &self.screen.unicode.width_data);
 }
 
 /// fills the window with the provided cell

src/gwidth.zig

···
 };
 
 /// returns the width of the provided string, as measured by the method chosen
-pub fn gwidth(str: []const u8, method: Method, data: *const DisplayWidth.DisplayWidthData) !usize {
+pub fn gwidth(str: []const u8, method: Method, data: *const DisplayWidth.DisplayWidthData) usize {
     switch (method) {
         .unicode => {
             const dw: DisplayWidth = .{ .data = data };
···
             return total;
         },
         .no_zwj => {
-            var out: [256]u8 = undefined;
-            if (str.len > out.len) return error.OutOfMemory;
-            const n = std.mem.replacementSize(u8, str, "\u{200D}", "");
-            _ = std.mem.replace(u8, str, "\u{200D}", "", &out);
-            return gwidth(out[0..n], .unicode, data);
+            var iter = std.mem.split(u8, str, "\u{200D}");
+            var result: usize = 0;
+            while (iter.next()) |s| {
+                result += gwidth(s, .unicode, data);
+            }
+            return result;
         },
     }
 }
···
     const alloc = testing.allocator_instance.allocator();
     const data = try DisplayWidth.DisplayWidthData.init(alloc);
     defer data.deinit();
-    try testing.expectEqual(1, try gwidth("a", .unicode, &data));
-    try testing.expectEqual(1, try gwidth("a", .wcwidth, &data));
-    try testing.expectEqual(1, try gwidth("a", .no_zwj, &data));
+    try testing.expectEqual(1, gwidth("a", .unicode, &data));
+    try testing.expectEqual(1, gwidth("a", .wcwidth, &data));
+    try testing.expectEqual(1, gwidth("a", .no_zwj, &data));
 }
 
 test "gwidth: emoji with ZWJ" {
     const alloc = testing.allocator_instance.allocator();
     const data = try DisplayWidth.DisplayWidthData.init(alloc);
     defer data.deinit();
-    try testing.expectEqual(2, try gwidth("👩‍🚀", .unicode, &data));
-    try testing.expectEqual(4, try gwidth("👩‍🚀", .wcwidth, &data));
-    try testing.expectEqual(4, try gwidth("👩‍🚀", .no_zwj, &data));
+    try testing.expectEqual(2, gwidth("👩‍🚀", .unicode, &data));
+    try testing.expectEqual(4, gwidth("👩‍🚀", .wcwidth, &data));
+    try testing.expectEqual(4, gwidth("👩‍🚀", .no_zwj, &data));
 }
 
 test "gwidth: emoji with VS16 selector" {
     const alloc = testing.allocator_instance.allocator();
     const data = try DisplayWidth.DisplayWidthData.init(alloc);
     defer data.deinit();
-    try testing.expectEqual(2, try gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .unicode, &data));
-    try testing.expectEqual(1, try gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .wcwidth, &data));
-    try testing.expectEqual(2, try gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .no_zwj, &data));
+    try testing.expectEqual(2, gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .unicode, &data));
+    try testing.expectEqual(1, gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .wcwidth, &data));
+    try testing.expectEqual(2, gwidth("\xE2\x9D\xA4\xEF\xB8\x8F", .no_zwj, &data));
 }
 
 test "gwidth: emoji with skin tone selector" {
     const alloc = testing.allocator_instance.allocator();
     const data = try DisplayWidth.DisplayWidthData.init(alloc);
     defer data.deinit();
-    try testing.expectEqual(2, try gwidth("👋🏿", .unicode, &data));
-    try testing.expectEqual(4, try gwidth("👋🏿", .wcwidth, &data));
-    try testing.expectEqual(2, try gwidth("👋🏿", .no_zwj, &data));
+    try testing.expectEqual(2, gwidth("👋🏿", .unicode, &data));
+    try testing.expectEqual(4, gwidth("👋🏿", .wcwidth, &data));
+    try testing.expectEqual(2, gwidth("👋🏿", .no_zwj, &data));
 }

src/widgets/View.zig

···
 
 /// Returns the width of the grapheme. This depends on the terminal capabilities
 pub fn gwidth(self: View, str: []const u8) usize {
-    return gw.gwidth(str, self.screen.width_method, &self.screen.unicode.width_data) catch 1;
+    return gw.gwidth(str, self.screen.width_method, &self.screen.unicode.width_data);
 }
 
 /// Fills the View with the provided cell