def unescape_html( string )
string.to_s.gsub(/&(.*?);/n) do
match = $1.dup
case match
when /\Aamp\z/ni then '&'
when /\Aquot\z/ni then '"'
when /\Agt\z/ni then '>'
when /\Alt\z/ni then '<'
when /\A#0*(\d+)\z/n then
if Integer($1) < 256
Integer($1).chr
else
if Integer($1) < 65536 and \
($KCODE[0] == ?u or $KCODE[0] == ?U)
[Integer($1)].pack("U")
else
"&##{$1};"
end
end
when /\A#x([0-9a-f]+)\z/ni then
if $1.hex < 256
$1.hex.chr
else
if $1.hex < 65536 and \
($KCODE[0] == ?u or $KCODE[0] == ?U)
[$1.hex].pack("U")
else
"&#x#{$1};"
end
end
else
"&#{match};"
end
end
end