Specify the way that Fn can get the Request out of your context.

The easiest way to instantiate this is to use the lens, but if you don't want to use lenses, define getRequest and setRequest.

Note that requestLens is defined in terms of getRequest and setRequest and vice-versa, so you need to define _one_ of these.

Convert an Fn application (provide a context, a context to response function and we'll create a WAI application by updating the Request value for each call).

The parts of the path, when split on /, and the query.

The main construct for Fn, route takes a context (which it will pass to all handlers) and a list of potential matches (which, once they match, may still end up deciding not to handle the request - hence the double Maybe). It can be nested.

 app c = route c [ end ==> index
                 , path "foo" / path "bar"  segment ? param "id ==> h]
   where index :: IO (Maybe Response)
         index = okText "This is the index."
         h :: Text -> Text -> IO (Maybe Response)
         h s i = okText ("got path foo" <> s <> ", with id=" <> i)

The route function (and all your handlers) return 'IO (Maybe Response)', because each can elect to not respond (in which case we will continue to match on routes). But to construct an application, we need a response in the case that nothing matched - this is what fallthrough does.

The connective between route patterns and the handler that will be called if the pattern matches. The type is not particularly illuminating, as it uses polymorphism to be able to match route patterns with varying numbers (and types) of parts with functions of the corresponding number of arguments and types.

Connects two path segments. Note that when normally used, the type parameter r is Req. It is more general here to facilitate testing.

Identical to '(//)', provided simply because it serves as a nice visual difference when switching from 'path'/'segment' to param and friends.

Matches a literal part of the path. If there is no path part left, or the next part does not match, the whole match fails.

Matches there being no parts of the path left. This is useful when matching index routes.

Matches anything.

Captures a part of the path. It will parse the part into the type specified by the handler it is matched to. If there is no segment, or if the segment cannot be parsed as such, it won't match.

A class that is used for parsing for param, paramOpt, and segment.

Matches on a single query parameter of the given name. If there is no parameters, or it cannot be parsed into the type needed by the handler, it won't match.

Matches on query parameters of the given name. If there are no parameters, or it cannot be parsed into the type needed by the handler, it won't match.

If the specified parameters are present, they will be parsed into the type needed by the handler, but if they aren't present or cannot be parsed, the handler will still be called.

Returns Text as a response.

Returns Html (in Text) as a response.

Returns Text as a response with a 500 status code.

Returns Html (in Text) as a response with a 500 status code.

Returns a 404 with the given Text as a body. Note that this returns a 'IO Response' not an 'IO (Maybe Response)' because the expectaiton is that you are calling this with fallthrough.

Returns a 404 with the given html as a body. Note that this returns a 'IO Response' not an 'IO (Maybe Response)' because the expectaiton is that you are calling this with fallthrough.

Redirects to the given url. Note that the target is not validated, so it should be an absolute path/url.