If you use HAML rather than ERB you can do something similar with a less than or greater symbol than after your tag.
> will remove any whitespace around your tag and < will remove any whitespace within it.
.float-left<
%p
Lorem ipsum dolor sit amet
is compiled to:
Lorem ipsum dolor sit amet
And…
%left_tag
%inside>
%right_tag
is compiled to:
If you're not using HAML it's definitely worth checking out.
