Sample function wrapper in Janet

The short example taken from file Datamap.janet, outlined below, shows the basic features of the Janet syntax used to create a wrapper for the LIP_remap_ooc routine. The file with the ''.janet'' extension is the source for the Janet translator. It can combine both Java and C languages, i.e. define Java a class that makes calls to C library functions.

 public class Datamap extends DataEncapsulator { 

 native "C" {
 #include <lip.h>
 #include <mpi.h>
 #include <mpio.h>
 }
 ...    
    
    public native "C" void remap_ooc (Datamap datamap,
              mpi.File datafile, mpi.File dataoutfile, int count, 
	      int pagesize, Datatype datatype, int flags)
    {
         LIP_Datamap new_datamap = (LIP_Datamap) `this.data`;
         int result = LIP_remap_ooc(`datamap.data`, &new_datamap, 
	     `datafile.data`, `dataoutfile.data`, `count`, 
	     `pagesize`, `datatype.handle`, `flags`);
         if (result != LIP_SUCCESS) `throw new LipException(#(result));`
    }
 ...
 }

The Datamap java class includes the remap_ooc native method which is written in C language. The code can refer to Java objects and throw Java exceptions using statements enclosed in special characters `` ` ''.

Created by Katarzyna Zając