perf(parse): reduce realloc for figcaptions

2 files changed, 26 insertions, 1 deletions

diff --git a/src/eval/Element.zig b/src/eval/Element.zig
index a8b424d..355e971 100644
--- a/src/eval/Element.zig
+++ b/src/eval/Element.zig
@@ -113,6 +113,24 @@ pub fn Simple(comptime tag: []const u8) type {
             destroy(self, alloc);
         }
 
+        pub fn toTag(self: *Self, alloc: Allocator, comptime target: []const u8) !*Simple(target) {
+            const el = try Simple(target).init(alloc);
+            self.conv(alloc, &el.content);
+            return el;
+        }
+
+        pub fn toEmpty(self: *Self, alloc: Allocator) !*Empty {
+            const el = try Empty.init(alloc);
+            self.conv(alloc, &el.content);
+            return el;
+        }
+
+        fn conv(self: *Self, alloc: Allocator, arr: *std.ArrayList(Element)) void {
+            arr.deinit(alloc);
+            arr.* = self.content;
+            alloc.destroy(self);
+        }
+
         fn destroy(context: *anyopaque, alloc: Allocator) void {
             var self: *Self = @ptrCast(@alignCast(context));
             for (self.content.items) |it| it.deinit(alloc);
diff --git a/src/eval/Image.zig b/src/eval/Image.zig
index 771c8ee..7991d69 100644
--- a/src/eval/Image.zig
+++ b/src/eval/Image.zig
@@ -45,7 +45,7 @@ fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
     const source = self.source orelse return el;
     var caption = try HTML.init(alloc, .content, "figcaption");
     errdefer caption.deinit();
-    try caption.content.append(alloc, try source.html(alloc));
+    try caption.appendContent(try source.html(alloc));
     try el.appendContent(caption);
     return el;
 }
@@ -65,4 +65,11 @@ test "html" {
     const h2 = try img.element().renderHTML(alloc);
     defer alloc.free(h2);
     try expect(eql(u8, h2, "<figure><img src=\"foo\" alt=\"bar\"></figure>"));
+
+    const in = try Element.Empty.init(alloc);
+    try in.content.append(alloc, (try Element.Literal.init(alloc, "caption")).element());
+    img.source = in.element();
+    const h3 = try img.element().renderHTML(alloc);
+    defer alloc.free(h3);
+    try expect(eql(u8, h3, "<figure><img src=\"foo\" alt=\"bar\"><figcaption>caption</figcaption></figure>"));
 }