how do breadcrumbs work?

Question

beyond the trivial

instance YesodBreadcrumbs MySite where
  breadcrumb RootR      = return ("home", Nothing)
  breadcrumb FirstPageR = return ("first page", Just RootR)
  breadcrumb SecondPageR = return ("second page", Just FirstPageR)

does anyone know how to implement breadcrumbs for situations where a specific page can be reached from several different parents for example?

thanks konstantin

Answer 1

Apologies as this isn't a technical answer but more of a UX answer...

where a specific page can be reached from several different parents for example

If that's the case, then your site's IA isn't conducive to breadcrumb navigation. Showing the same page with two different sets of breadcrumbs will only confuse users. I'd suggest that you instead reference the content in one section of the site from the other rather than duplicate it.