Using Ternary DAGs for Spelling Correction

// Ternary DAG spellchecker
// (c) Peter Kankowski, 2008. kankowski@narod.ru

#pragma pack(push)
#pragma pack(1)

// Dictionary node stored in file
struct ST_FILE_NODE {
	char ch;
	char _padding;
	unsigned short left;
	unsigned short right;
	unsigned short middle;
};
typedef struct ST_FILE_NODE ST_FILE_NODE;
#pragma pack(pop)

#define ST_DICT_SIGNATURE "Aba dict"
#define ST_MAX_WORD 100

// Open a dictionary, returns NULL in case of error
ST_FILE_NODE * ST_open_dict (const char * filename);

// Returns a non-zero value if the word is present in the dictionary
int ST_find_exact (ST_FILE_NODE * dict, const char * word);

// Enumerate spelling suggestions (fuzzy matches)
void ST_enum_suggestions (ST_FILE_NODE * dict, const char * word,
						  void (* enumproc)(const char*, void*), void * param);

// Close the dictionary
void ST_close_dict (ST_FILE_NODE * dict);