// tbl.h: an abstract API for tables with string keys.//// Written by Tony Finch <dot@dotat.at>// You may do anything with this. It has no warranty.// <http://creativecommons.org/publicdomain/zero/1.0/> #pragma once // A table is represented by a pointer to this incomplete struct type.// You initialize an empty table by setting the pointer to NULL.//typedef struct Tbl Tbl;#if defined(__plan9__)#pragma incomplete Tbl#endif // Get the value associated with a key.// Returns NULL if the key is not in the Table.//void *Tgetl(Tbl *tbl, const char *key, usize klen);void *Tget(Tbl *tbl, const char *key); // Returns false if the key is not found, otherwise returns true and// sets *rkey and *rval to the table's key and value pointers.//bool Tgetkv(Tbl *tbl, const char *key, usize klen, const char **rkey, void **rval); // Associate a key with a value in a table. Returns a new pointer to// the modified table. If there is an error it sets errno and returns// NULL. To delete a key, set its value to NULL. When the last key is// deleted, Tset() returns NULL without setting errno. The key and// value are borrowed not copied.//// Errors:// EINVAL - value pointer is not word-aligned// ENOMEM - allocation failed//Tbl *Tsetl(Tbl *tbl, const char *key, usize klen, void *value);Tbl *Tset(Tbl *tbl, const char *key, void *value);Tbl *Tdell(Tbl *tbl, const char *key, usize klen);Tbl *Tdel(Tbl *tbl, const char *key); // Deletes an entry from the table as above, and sets *rkey and *rval// to the removed key and value pointers.//Tbl *Tdelkv(Tbl *tbl, const char *key, usize klen, const char **rkey, void **rval); // Find the next item in the table. The p... arguments are in/out// parameters. To find the first key, pass *pkey=NULL and *pklen=0.// For subsequent keys, *pkey must be present in the table and is// updated to the lexicographically following key. Returns false or// NULL when there are no more keys.//bool Tnextl(Tbl *tbl, const char **pkey, usize *pklen, void **pvalue);bool Tnext(Tbl *tbl, const char **pkey, void **pvalue);const char *Tnxt(Tbl *tbl, const char *key);