Remove warning about unused i in Java.

[ams-tschoening]

This fixes kaitai-io/kaitai_struct#365 in a somewhat easy manner and can be improved in future if needed at all.

[GreyCat]

What really bothers me about this solution is that it's a hack that effectively just fools the compiler warning system. If we'll accept it as a solution for now, we're bound to get more WTF questions from users later...

[ams-tschoening]

Do you really think one will have such a detailed look at the generated code in future? I don't unless I have problems or Eclipse marks my project with a warning sign. And currently there's no way to get rid of that sign unless one manually removes the usage of i after each and every new generation of code. I have 3 places in two files already and that started to annoy me.

Add a FIXME like in other cases already, linking to the issue. You can even output it in the generated Java code, so everyone with such a detailed look at the generated code can directly start working on a cleaner solution. ;-)

[generalmimon]

FWIW, I recently fixed an issue with the unused i variable in Go - see the fix and the comment:

kaitai_struct_compiler/shared/src/main/scala/io/kaitai/struct/languages/GoCompiler.scala

Lines 324 to 329 in 8913518

	// FIXME: Go throws a fatal compile error when the `i` variable is not used (unused variables
	// can only use the blank identifier `_`, see https://go.dev/doc/effective_go#blank), so we have
	// to silence it like this. It would be nice to be able to analyze all expressions that appear
	// in the loop body to decide whether to generate `for _ := range` or `for i := range` here, but
	// that would be really difficult to do properly in KSC with the current architecture.
	out.puts("_ = i")

In Go, an unused variable is even a fatal error (not a warning) and the .go source file will not compile, so this was clearly needed. I used an "approved" workaround taken directly from the Go docs, see https://go.dev/doc/effective_go#blank.