dns.types

format_ipv6(groups) -> address

Format 8 u16 groups into RFC5952 canonical IPv6 string

Formats an array of 8 16-bit groups into RFC5952 canonical form:

• Lowercase hex, no leading zeros
• Longest run of consecutive zero groups replaced with ::
• :: only used for runs of 2 or more zero groups
• Leftmost longest run wins on tie