package virtual_dom

merge_classes_and_styles groups together the class attributes and style attributes from the given list into a single style and class attribute, e.g.:

class="foo"; style="color:blue"; class="bar"; id="id"; style="margin:30px;"

becomes

class="foo bar"; style="color:blue; margin:30px;"; id="id"

If there is no style attribute the empty Css_gen.t will be passed to f. Most of the time you probably want to use add_style instead.