Allow literal : in routes

[DavidSouther]

Feature Request

Allow a way to register routes (and route fragments) that include a literal :

Motivation

REST (GCP) Api (Azure) Guidelines† (OpenAPI) suggest mechanisms to define custom verbs using POST /collection/{id}:verb. In axum, this is ambiguous as /collection/12:archive for the route /collection/:id:verb matches get(Path(id): Path<String>) as "12:archive". That is, the :verb gets ignored, and the entire fragment gets assigned to the first parameter match.

† Ok it's not technically in there, but it's not forbidden, as far as I can tell

Proposal

Switch (or provide the option) to use {curly-delimited} path templates. This conveniently aligns with the OpenAPI path templating spec.

Alternatives

Recognize Additional :foo after the first :path in a route fragment as literal. That is, for a route section between two "/", only the first :portion is recognized.

[DavidSouther]

Looks like this might be a better issue for matchit.

Edit: So it is: ibraheemdev/matchit#23

[davidpdrsn]

Yep. There isn't anything axum can do about this so I'll close since we already have a matchit issue.