WIP: container rendering for borders + container element rendering

src/color.zig

@@ -1,16 +1,32 @@
 const std = @import("std");
 
 pub const Color = union(enum) {
-    default,
-    index: u8,
+    ansi: enum(u32) {
+        reset = 0,
+        black = 30,
+        red,
+        green,
+        yellow,
+        blue,
+        magenta,
+        cyan,
+        white,
+        bright_black = 90,
+        bright_red,
+        bright_green,
+        bright_yellow,
+        bright_blue,
+        bright_magenta,
+        bright_cyan,
+        bright_white,
+    },
     rgb: [3]u8,
 
     pub fn eql(a: Color, b: Color) bool {
         switch (a) {
-            .default => return b == .default,
-            .index => |a_idx| {
+            .ansi => |a_idx| {
                 switch (b) {
-                    .index => |b_idx| return a_idx == b_idx,
+                    .ansi => |b_idx| return a_idx == b_idx,
                     else => return false,
                 }
             },
@@ -25,6 +41,30 @@ pub const Color = union(enum) {
         }
     }
 
+    pub fn write(this: Color, writer: anytype, comptime coloring: enum { fg, bg, ul }) !void {
+        switch (this) {
+            .ansi => |index| blk: {
+                if (index == .reset)
+                    break :blk switch (coloring) {
+                        .fg => try std.fmt.format(writer, "39", .{}),
+                        .bg => try std.fmt.format(writer, "49", .{}),
+                        .ul => try std.fmt.format(writer, "59", .{}),
+                    };
+
+                break :blk switch (coloring) {
+                    .fg => try std.fmt.format(writer, "38;5;{d}", .{@intFromEnum(index)}),
+                    .bg => try std.fmt.format(writer, "48;5;{d}", .{@intFromEnum(index)}),
+                    .ul => try std.fmt.format(writer, "58;5;{d}", .{@intFromEnum(index)}),
+                };
+            },
+            .rgb => |rgb| switch (coloring) {
+                .fg => try std.fmt.format(writer, "38;2;{d};{d};{d}", .{ rgb[0], rgb[1], rgb[2] }),
+                .bg => try std.fmt.format(writer, "48;2;{d};{d};{d}", .{ rgb[0], rgb[1], rgb[2] }),
+                .ul => try std.fmt.format(writer, "58;2;{d};{d};{d}", .{ rgb[0], rgb[1], rgb[2] }),
+            },
+        }
+    }
+
     pub fn rgbFromUint(val: u24) Color {
         const r_bits = val & 0b11111111_00000000_00000000;
         const g_bits = val & 0b00000000_11111111_00000000;