Generic AVL trees module in C (Header)

avl.h

typedef enum balancefactor { LH , EH , RH } BalanceFactor;

typedef struct treenode *Tree;

Tree createTree(void);
void emptyTree(Tree t);
int treeHeight(Tree t);
int treeSize(Tree t);
int isEmpty(Tree t);

int compareStrings(void *s1 , void *s2);
int searchKey(Tree t, void* e, int (*f)(void* , void*));
Tree insertTree(Tree t, void* e, int *cresceu, int (*f)(void* , void*));
Tree insertRight(Tree t, void* e, int *cresceu, int (*f)(void* , void*));
Tree balanceRight(Tree t);
Tree insertLeft(Tree t, void* e, int *cresceu, int (*f)(void* , void*));
Tree balanceLeft(Tree t);
Tree rotateLeft(Tree t);
Tree rotateRight(Tree t);
void TreeToArrayStrings(Tree t, int *pos, int linesize, char** array, char* (*toStr)(void*));