Support clojure-dart

[jgoday]

Support clojure-dart source files.

Currently, clojure-dart files are basically clojure source files that compiles to dart.
See:

• https://github.com/Tensegritics/ClojureDart
• https://github.com/Tensegritics/ClojureDart/blob/816344d4abaf5165fe55ebf3af662af7d3ab3ca8/doc/differences.md

Expected behavior

Clojure-mode should support clojure-dart files (.cljd).

Actual behavior

Current clojure-mode does not detect .cljd files.

Steps to reproduce the problem

Environment & Version information

clojure-mode version

clojure-mode (version 5.14.0)

Emacs version

28.0.91

Operating system

MacOS 12.0.1

[bbatsov]

Are there any syntax differences between Clojure and ClojureDart?

[jgoday]

Are there any syntax differences between Clojure and ClojureDart?

As pointed here: https://github.com/Tensegritics/ClojureDart/blob/main/doc/differences.md
there are some minor/very subtle differences (taken directly from clojureDart documentation)

• Exceptions: Try/catch with additional stacktrace alongside with the exception

(try
  ...
  (catch io/HttpException e ; no stack trace binding
    ...)
  (catch Exception e st ; stack trace binding
    ...))

• Member names as strings

(. a "[]=" i v)

• Dart literals

#dart [1 2 3] ; a growable List<dynamic>
#dart ^:fixed [1 2 3] ; a fixed List<dynamic>
#dart ^int [1 2 3] ; a growable List<int>
#dart ^:fixed ^int [1 2 3] ; a fixed List<int>

• Reify with extends

(reify
  :extends material/StatelesWidget
  (build [_ ctx] ...))

[vemv]

Released as clojure-mode 5.15.0, which will be available within a couple hours