simap/amap.h

#ifndef AMAP_H
#define AMAP_H

/** Operations possible on the abstract map (setting with NULL should lead to getting NULL (can tombstone it though) */
enum AMAP_OP { AMAP_SET = 0, AMAP_GET = 1, AMAP_ERASE = 2 };
typedef enum AMAP_OP AMAP_OP;

/**
 * Function-abstraction for an abstract map data type.
 *
 * Operations:
 *
 * 		AMAP_SET Saves a mapping from key->ptr in map. ptr==NULL "tombstones" the mapping to return NULL. Returns null on error!
 * 		AMAP_GET Gets the symbol at key (the ptr parameter is unused). Returns "ptr" if there is no data for the key.
 * 		AMAP_ERASE Erases the symbol table so it becomes empty again. Can never fail, returns NULL.
 *
 * @param amap_instance The instance we operate upon.
 * @param op Defines which operation the caller wants.
 * @param key The key (both for SET and GET). This pointer can get easily invalidated so you might need a copy or you do Trie, etc.
 * @param ptr When adding a ptr (data) to the map / table, the key will point to this ptr. Also the nt-found ptr to return in case of GET.
 * @returns The ptr / data stored for the key, or NULL on tombstone or when not stored yet or op is SET and there was an error.
 */
typedef void* (*amap)(void *amap_instance, AMAP_OP op, const char *key, void *ptr);

#endif /* AMAP_H */