Description
In #9017 (comment)
@mhegazy suggested the possibility that TS could include an API that makes it easy to build incremental compilers, similar to the --watch behavior of TSC.
Given a ts.Program object, and a string[] of files that were modified, re-read and parse only the changed files, getPreEmitDiagnostics only for the changed files, emit only the changed files, and give the updated Program.
Right now it's too much work for us to write our own tsc that has the --watch behavior.
cc @IgorMinar