my %transforms = (
    ( map { "$_<" => "$_E<lt>" } 'A'..'Z' ),
    ">"  => "E<gt>",
    " "  => "E<32>",
    "\t" => "E<9>",
    "="  => "E<61>",
    "/"  => "E<sol>",
    "|"  => "E<verbar>",
);

 
s{ ( [A-Z]< | [>/|] | ^[ \t=] ) }{$transforms{$1}}g;