Source Line, File, Directory Identifiers

These all respect the #line directive (See [Compiler Directives](compiler.fsx)).

Current line number

1: 
printfn "__LINE__ is %s" __LINE__

Full path of the source file directory

1: 
printfn "__SOURCE_DIRECTORY__ is %s" __SOURCE_DIRECTORY__

Filename (no path) of the source file

1: 
printfn "__SOURCE_FILE__ is %s" __SOURCE_FILE__