Creates a link to the
reference name if the name exists. If text is given it
is used as the link
text, otherwise name is used.
# File lib/rdoc/markup/to_html_crossref.rb, line 51
def cross_reference name, text = nil
lookup = name
name = name[1..-1] unless @show_hash if name[0, 1] == '#'
name = "#{CGI.unescape $'} at #{$1}" if name =~ /(.*[^#:])@/
text = name unless text
link lookup, text
end