somBeginPersistentIds - Example Code

#include <som.h>
/* This is the way to create somIds efficiently */
static string id1Name = "whoami";
static somId somId_id1 = &id1Name;
/*
   somId_id1 will be registered the first time it is used
   in an operation that takes a somId, or it can be explicitly
   registered using somCheckId.
*/

main()
{
   somId id1, id2;
   string id2Name = "whereami";

   somEnvironmentNew();
   somBeginPersistentIds();
   id1 = somCheckId(somId_id1); /* registers the id as persistent */
   somEndPersistentIds();
   id2 = somIdFromString(id2Name); /* registers the id */

   SOM_Assert(!strcmp("whoami", somStringFromId(id1)), SOM_Fatal);
   SOM_Assert(!strcmp("whereami", somStringFromId(id2)), SOM_Fatal);

   id1Name = "it does matter"; /* because it is persistent */
   id2Name = "it doesn't matter"; /* because it is not persistent */

   SOM_Assert(strcmp("whoami", somStringFromId(id1)), SOM_Fatal);
   /* The id1 string has changed */
   SOM_Assert(!strcmp("whereami", somStringFromId(id2)), SOM_Fatal);
   /* the id2 string has not */
}