SCEX, SCPL extension file. really just an scpl file with another extension but
SCEX is needed as an extension to import it as an module.

scpl file. an non-compiled scpl source code file, the input file of the compiler.

scbc, scpl bytecode file. output of compiler and input to vm.

scdc, scpl descriptor file. output of compiler and input to vm. contains information for
debugging; information what part of bytecode was once what source code.