#ifndef TABLE_INCLUDED
#define TABLE_INCLUDED
#include <stddef.h>

#define T Table_T
typedef struct T *T;

extern T Table_new(size_t hint, int compare(const char *x, const char *y));
/*
creates, initializes, and returns a new associative table. hint is an
estimate of the number of key-value pairs the table is expected to
hold. All tables can hold an arbitrary number of pairs, but an
implementation may use hint to improve performance. compare is used in
subsequent calls to Table_get and Table_put to compare keys; for keys
x and y, compare(x,y) must return 0 if x==y, a value < 0 if x < y, and
a value > 0, if x > y. It is a checked runtime error for compare to be
NULL.  */

extern void Table_free(T *table);
/*
deallocates *table and its keys, but not its values, and sets *table
to NULL. It is a checked runtime error for table or *table to be NULL.
*/

extern void Table_put(T table, char *key, void *value);
/*
adds the key-value pair to table, replacing the previous value
associated with key, if there is one. key is copied.
*/

extern void *Table_get(T table, char *key);
/*
returns the value associated with key, if it's in table. Otherwise,
Table_get returns NULL.
*/

extern int Table_length(T table);
/*
returns the number of key-value pairs in table.
*/

extern void Table_map(T table,
	void apply(char *key, void **value, void *cl), void *cl);
/*
calls apply for every key-value pair in table; the second argument is
a pointer to the value associated with key, so apply can change the
values. apply and cl are a closure: clients can pass an
application-specific pointer, cl, to Table_map and this pointer is
passed along to apply at each call. It is a checked runtime error for
apply to be NULL, or for apply to change the contents of table by
calling Table_put. It is an unchecked runtime error for apply to
change the string pointed to by key.
*/

/*
It is a checked run-time error to pass a NULL key or table to any
function in this interface.
*/

#undef T
#endif