Typed Clojure uses local type argument synthesis to automatically synthesise type arguments to polymorphic functions. Some inference cases are hard to synthesise, which usually cause the inference engine to fail.
These cases require manual annotation of type arguments, which are potentially different at every function application.
Typed Clojure runs forms through the Clojure analyser, and parses the results of analysis.
I need a mechanism to communicate to Typed Clojure on a per-function-call basis.
Modify the analyser to preserve metadata attached to function calls.
Particular reader metadata keys are hardcoded to survive analysis, such as :tag.
Analysing this form loses any mention of :a, but keeps :tag in a special field in the result of analysis.
Modify the analyser to add a metadata field for function invocations.
Attached example patch.