my $pathex2   = qr/[0-9A-F]{2}/i;	# exactly 2 hex digits
my $pathex2p  = qr/[0-9A-F]{2,}/i;	# 2 or more hex digits
my $pathexX1t4= qr/[0-9A-FX]{1,4}/i;	# 1-4 hex/X digits
my $pathexX1t8= qr/[0-9A-FX]{1,8}/i;	# 1-8 hex/X digits
my $patopt_h  = qr/h?/i;		# optional trailing H/h
my $patoptname= qr/(?:\"[^\"]+\")?/;	# optional quoted literal (name)

my $patint       = qr/\bINT\s?$pathex2$patopt_h/;		# INT <byte>
my $patmem_16_16 =
	qr/\bMEM\s?$pathexX1t4$patopt_h:$pathexX1t4$patopt_h/;	# MEM <addr>:<addr>
my $patmem_32    = qr/\bMEM\s?$pathexX1t8$patopt_h/;		# MEM <addr>
my $patportrange = qr/
	\bPORT\s?$pathexX1t4$patopt_h\-$pathexX1t4$patopt_h/x;	# PORT <range>
my $patportsingle= qr/\bPORT\s?$pathexX1t4$patopt_h/;		# PORT <single>
my $pattable     = qr/\#[0-9A-Z][0-9]{4}\b/;			# #<letter><4 digits>
my $pataccureg   = qr/\bE?A[XHL]=$pathex2p$patopt_h/;		# EAX/AH/AL assignment
my $patregequ    = qr/
	(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=$pathex2p$patopt_h
/x;					# a single register entry
my $patreglists  = qr/
	(?:\/$patregequ)+
/x;					# one or more "/<reg>" entries

our $hyperlinkpattern = qr/
    # 1. INT with register list and optional name
    (?<intplus>
        $patint
        $patreglists
        $patoptname
    )
    |
    # 2. INT with only optional name
    (?<intonly>
        $patint
        $patoptname
    )
    |
    # 3. EAX\/AH\/AL equation with optional register list and optional name
    (?<regonly>
        $pataccureg
        (?:\/$patregequ)*
        $patoptname
    )
    |
    # 4. Table reference
    (?<table>
        $pattable
    )
    |
    # 5. MEM far address (addr:addr) with optional name
    (?<mem_16_16>
        $patmem_16_16
        $patoptname
    )
    |
    # 6. MEM single address with optional name
    (?<mem_32>
        $patmem_32
        $patoptname
    )
    |
    # 7. @ reference (addr:addr) with optional name
    (?<call>
        \@$pathexX1t4$patopt_h:$pathexX1t4$patopt_h
        $patoptname
    )
    |
    # 8. PORT range with optional name
    (?<portrange>
        $patportrange
        $patoptname
    )
    |
    # 9. PORT single value with optional name
    (?<portsingle>
        $patportsingle
        $patoptname
    )
/x;