Link Header parser

linkheader is a parser for the RFC8288.

Goals

• Forgiving parser.
  • A link with no "rel" param is not an error.
  • A link with many "rel" params is not an error.
  • UTF-8 characters outside the US-ASCII range are not an error.
  • A link with many "anchor" params is not an error.
• Quoted and unquoted param values are equivalent. E.g. hreflang=en is the same as hreflang="en".
• Collect the link relation type when available.
• Explode to individual links when given a multi-token "rel".
• Change the link context when a valid "anchor" is present.
• Star params (e.g. title*=UTF-8'en'foo%20bar) expect a valid RFC8187 value.
• Compose relative targets with the given context.
• Collect the "title" param prioritising title* when present.
• Collect the "hreflang" param.
• Collect the "type" param.
• Collect the "media" param.

Non-goals

• "rev" is not treated specially. It is just another param.
• "rel" values are not validated against the IANA registry.
• Language tags RFC5646 are not parsed.
• RFC8187 values not in UTF-8 are not decoded.
• Media types RFC2046 are not parsed.
• The special (HTML) "rel" alternate stylesheet is not handled. Any multi-token "rel" expands to individual links with a different relation type.

Licence

linkheader is licensed under the MIT License.