Single D app entered multiple times from command line

[Vladimir Panteleev]

On Monday, 23 September 2019 at 19:14:15 UTC, Brett wrote:
> I imagine I could potentially create a separate process that 
> has a communication layer between it and the D program but I'm 
> hoping it would be less work.

You're pretty much describing a client-server design. A lot of 
software does work in this way, e.g.:

- MS toolchain spawns mspdbsrv to write PDB files
- Gradle (Java build tool) spawns a daemon which caches 
information in memory
- Git on Windows also creates long-lived processes to cache 
filesystem information

The simplest design would be for the server to listen on a named 
pipe (perhaps named after the current directory), and the client 
to do nothing but forward the command-line arguments and input to 
the daemon through the pipe, then read back the result and 
present it to the user.