* Introduce RoutePattern
Introduces RoutePattern - a new parser and representation for routing
templates, defaults, and constraints.
This is a new representation for all of the 'inputs' to routing that is
immutable and captures 'out of line' information for defaults and
constraints.
This will allow us to unify the handling of constraints and values from
attribute style routes and conventional style routes.
Here's a code dump of the parts of the Dispatcher prototype codebase
that are needed to get us off the ground.
This first cut attempts to use part of routing where possible, and not
all of those changes will be long-lasting.
I'll leave comments through thoughout the PR for education.
This refactor introduces two major changes
1. Now creating the 'handler' delegate happens inside the endpoint
middleware. This allows you to short circuit even harder, AND to create
endpoint funcs that capture and use 'next' to rejoin the middleware
pipeline.
2. Relayered the implementation to have routing plug into the dispatcher.
It wasn't immediately apparent to me that this was the right thing to do,
but I think we will need to do things this way to deliver the kind of
back-compat experience we need to do.
The idea that I have is that 'attribute routing' will be the 'default'
entry in the dispatcher. Adding additional conventional routes or other
IRouter-based extensibility will be possible through adapters - but the
default experience will be to add items to the 'attribute route'.
So. We will need to port the attribute routing infrastructure to the
dispatcher library.
We may also need to make RVD into a subclass of something in the
dispatcher assembly.
Ryan Nowak
James Newton-King
Jass Bagga
Pranav K
Kiran Challa
jacalvar
Ajay Bhargav Baaskaran
N. Taylor Mullen