I'd like to write Intellij plugin and I wonder is it possible to do it in Go language? If so, what are my options; as pure go? as compiled to bytecode program acting as service and incorporated in plugin jar? Maybe something else? I want this to be fast and I hope it's not limited to JVM languages.
I'd like to write Intellij plugin and I wonder is it possible to do it in Go language?
As long as the language supports working with JVM it will be possible to do it. Otherwise no. As Go does not support this for now, the answer is no, you cannot.
So far I know of plugins written in Java, Kotlin, Scala.
I want this to be fast and I hope it's not limited to JVM languages.
In many many cases Java / JVM is just as fast if not faster then Go code. Keep in mind that the IDE is meant for being opened hours at a time and that gives the JVM a fairly good chance to optimize the code on-the-fly which can make it even faster than before.
For example the Go plugin for IntelliJ had a long standing problem with Delve (the Go debugger) as it was sending requests too fast to be handled in-order by Go and a special RPC implementation was needed in Delve. No other editors were this fast.