ReferenceOverride is an optional function callback that is called every time a reference is resolved.
In Markdown, the link reference syntax can be made to resolve a link to a reference instead of an inline URL, in one of the following ways:
* [link text][refid] * [refid]
Usually, the refid is defined at the bottom of the Markdown document. If this override function is provided, the refid is passed to the override function first, before consulting the defined refids at the bottom. If the override function indicates an override did not occur, the refids at the bottom will be used to fill in the link details.
p.r = renderer p.flags = extensions p.refOverride = opts.ReferenceOverride p.refs = make(map[string]*reference) p.maxNesting = 16