1 files changed, 104 insertions, 0 deletions
diff --git a/src/eval/html/Void.zig b/src/eval/html/Void.zig
new file mode 100644
index 0000000..58550f4
--- /dev/null
+++ b/src/eval/html/Void.zig
@@ -0,0 +1,104 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const List = std.ArrayList;
+const html = @import("html.zig");
+const Element = @import("Element.zig");
+const Error = Element.Error;
+
+alloc: Allocator,
+tag: []const u8,
+attributes: std.StringArrayHashMap([]const u8),
+class_list: std.BufSet,
+
+pub const Self = @This();
+
+pub fn init(alloc: Allocator, tag: []const u8) Error!*Self {
+    const v = try alloc.create(Self);
+    v.* = .{
+        .alloc = alloc,
+        .tag = tag,
+        .attributes = .init(alloc),
+        .class_list = .init(alloc),
+    };
+    return v;
+}
+
+pub fn element(self: *Self) Element {
+    return .{ .vtable = .{ .render = Self.render }, .ptr = self };
+}
+
+pub fn setAttribute(self: *Self, k: []const u8, v: []const u8) Error!void {
+    try self.attributes.put(try self.alloc.dupe(u8, k), try self.alloc.dupe(u8, v));
+}
+
+pub fn removeAttribute(self: *Self, k: []const u8) void {
+    _ = self.attributes.orderedRemove(k);
+}
+
+pub fn hasAttribute(self: *Self, k: []const u8) bool {
+    return self.attributes.contains(k);
+}
+
+pub fn appendClass(self: *Self, v: []const u8) Error!void {
+    try self.class_list.insert(v);
+}
+
+pub fn hasClass(self: *Self, v: []const u8) bool {
+    return self.class_list.contains(v);
+}
+
+pub fn removeClass(self: *Self, v: []const u8) void {
+    self.class_list.remove(v);
+}
+
+fn render(context: *anyopaque, alloc: Allocator) Error![]const u8 {
+    const self: *Self = @ptrCast(@alignCast(context));
+    const attr = try renderAttribute(alloc, &self.attributes, &self.class_list);
+    defer if (attr) |it| alloc.free(it);
+    var acc = try List(u8).initCapacity(alloc, self.tag.len + 2);
+    errdefer acc.deinit(alloc);
+    try acc.append(alloc, '<');
+    try acc.appendSlice(alloc, self.tag);
+    if (attr) |it| try acc.appendSlice(alloc, it);
+    try acc.append(alloc, '>');
+    return acc.toOwnedSlice(alloc);
+}
+
+fn renderAttribute(alloc: Allocator, attributes: *std.StringArrayHashMap([]const u8), class_list: *std.BufSet) Error!?[]const u8 {
+    const class = try renderClass(alloc, class_list);
+    defer if (class) |it| {
+        _ = attributes.orderedRemove("class");
+        alloc.free(it);
+    };
+    if (class) |it| try attributes.put("class", it);
+    var iter = attributes.iterator();
+    if (iter.len == 0) return null;
+    var acc = try List(u8).initCapacity(alloc, iter.len);
+    errdefer acc.deinit(alloc);
+    try acc.append(alloc, ' ');
+    var i: usize = 0;
+    while (iter.next()) |it| : (i += 1) {
+        try acc.appendSlice(alloc, it.key_ptr.*);
+        try acc.appendSlice(alloc, "=\"");
+        const escape = try html.escape(alloc, it.value_ptr.*);
+        defer alloc.free(escape);
+        try acc.appendSlice(alloc, escape);
+        try acc.append(alloc, '"');
+        if (i < iter.len - 1) try acc.append(alloc, ' ');
+    }
+    return try acc.toOwnedSlice(alloc);
+}
+
+fn renderClass(alloc: Allocator, class_list: *std.BufSet) Error!?[]const u8 {
+    const n = class_list.count();
+    if (n == 0) return null;
+    var acc = try List(u8).initCapacity(alloc, n);
+    errdefer acc.deinit(alloc);
+    var iter = class_list.iterator();
+    var i: usize = 0;
+    while (iter.next()) |it| : (i += 1) {
+        try acc.appendSlice(alloc, it.*);
+        if (i < n - 1) try acc.append(alloc, ' ');
+    }
+    return try acc.toOwnedSlice(alloc);
+}