feat: prettify json representation of themes

src/theme.zig

@@ -41,6 +41,40 @@ tokens: Tokens,
 
 pub const FontStyle = enum { normal, bold, italic, underline, undercurl, strikethrough };
 pub const Style = struct { fg: ?Color = null, bg: ?Color = null, fs: ?FontStyle = null };
-pub const Color = struct { color: u24, alpha: u8 = 0xFF };
+pub const Color = struct {
+    color: u24,
+    alpha: u8 = 0xFF,
+
+    pub fn jsonStringify(self: @This(), writer: anytype) !void {
+        try writer.beginObject();
+        try writer.objectField("color");
+        try writer.print("\"#{X:0>6}\"", .{self.color});
+        try writer.objectField("alpha");
+        try writer.print("{d}", .{self.alpha});
+        try writer.endObject();
+    }
+
+    pub fn jsonParse(_: std.mem.Allocator, source: anytype, _: std.json.ParseOptions) !@This() {
+        var color: Color = .{ .color = 0 };
+        if (try source.next() != .object_begin) return error.UnexpectedToken;
+        var key = try source.next();
+        while (key != .object_end) : (key = try source.next()) {
+            if (key != .string) return error.UnexpectedToken;
+            if (std.mem.eql(u8, key.string, "color")) {
+                const value = try source.next();
+                if (value != .string) return error.UnexpectedToken;
+                if (value.string.len != 7 or value.string[0] != '#') return error.InvalidNumber;
+                color.color = try std.fmt.parseInt(u24, value.string[1..], 16);
+            } else if (std.mem.eql(u8, key.string, "alpha")) {
+                const value = try source.next();
+                if (value != .number) return error.UnexpectedToken;
+                color.alpha = try std.fmt.parseInt(u8, value.number, 10);
+            }
+        }
+        return color;
+    }
+};
 pub const Token = struct { id: usize, style: Style };
 pub const Tokens = []const Token;
+
+const std = @import("std");