EEx multiple callbacks with `-> %>…<% end` format

[LostKobrakai]

Environment

• Elixir & Erlang/OTP versions (elixir --version): 1.7.3 / 21
• Operating system: MacOS X

Current behavior

<%= component(ComponentsWeb.GridListView, [list: ["a", "b"]], fn assigns -> %>
  <div style="display: inline-block">
    <h1><%= @item %></h1>
  </div>
<% end, fn assigns -> %>
  <div style="display: inline-block">
    <h1><%= @item %></h1>
  </div>
<% end) %>

Having this in an eex template I get an syntax error: ** (SyntaxError) lib/components_web/templates/page/index.html.eex:5: unexpected token: end

Expected behavior

I'm not sure if this is purposefully not possible, but having the possiblity to define multiple -> %>…<% end callbacks for a single function call would enable the possibiltiy to build components with multiple slots to be filled.

[LostKobrakai]

I'm just wondering if there's a chance this could make it into 1.8 or if I'd need to wait for 1.9 to build something like the above example?

[josevalim]

Since it is not a regression, you would have to wait until 1.9, unfortunately.

[LostKobrakai]

I've just found another case (notice the list around the callbacks):

<%= component(ComponentsWeb.GridListView, [list: ["a", "b"]], [fn assigns -> %>
  <div style="display: inline-block">
    <h1><%= @item %></h1>
  </div>
<% end, fn assigns -> %>
  <div style="display: inline-block">
    <h1><%= @item %></h1>
  </div>
<% end]) %>

I'd just do a PR handling trailing ] like trailing ) to end. This should be just fine, right?

[josevalim]

@LostKobrakai yes. we should probably put those in a module attribute and re-use them. We should also add } to the list.