Association List For Storing Name-Value Pairs

**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.

This Assoctiation List class is closely related to the HTList Class as it simply is a list of a specific list element containing a characters based name/value pair. Lookups from association list can be case sensitive and or prefix based.

This module is implemented by HTAssoc.c, and it is a part of the W3C Sample Code Library.

#ifndef HTASSOC_H
#define HTASSOC_H

#include "HTList.h"

typedef HTList HTAssocList;

typedef struct {
    char * name;
    char * value;
} HTAssoc;

Creation and Deletetion Methods

These methods create and deletes and association list

extern HTAssocList * HTAssocList_new (void);
extern BOOL 	     HTAssocList_delete (HTAssocList * alist);

Add an Element to a List

We have two methods for adding new elements - you can either add unconditionally or replace any existing element with the same name but a new value. In replacing an element, the search is case insensitive prefix match! A new list element is added to the beginning of the list so that it is the first element just after the head element.

extern BOOL HTAssocList_addObject (
	HTAssocList *	alist,
	const char *	name,
	const char *	value);

extern BOOL HTAssocList_replaceObject (
	HTAssocList *	list,
	const char * 	name,
	const char *	value);

Remove an Element from a List

Remove the element with the given name from the list. Search is case insensitive prefix match!

extern BOOL HTAssocList_removeObject (
	HTAssocList * 	list,
	const char * 	name);

Search for Element in a list

We have a small set of methods for searching a specific element within a list.

Case Insensitive, Prefix Match

In many situations, the values of associations are case insensitive - use this method to search the list using case insensitive comparison. Also, you can search for matching prefixes and not the whole string, for example "foo" matches "football"

extern char * HTAssocList_findObject (
	HTAssocList *	alist,
	const char *	name);

Case Insensitive, Exact Match

In case you want case insensitive, exact match

extern char * HTAssocList_findObjectExact (
	HTAssocList *	alist,
	const char *	name);

Case Sensitive, Prefix Match

In case you want case sensitive, prefix match

extern char * HTAssocList_findObjectCaseSensitive (
	HTAssocList *	list,
	const char *	name);

Case Sensitive, Exact Match

And finally if you want case sensitive, exact match

extern char * HTAssocList_findObjectCaseSensitiveExact (
	HTAssocList *	list,
	const char * 	name);

Get Name and Values

Use this to get the name and value of a assoc object

#define HTAssoc_name(me)	((me) ? (me)->name : NULL)
#define HTAssoc_value(me)	((me) ? (me)->value : NULL)

Traverse list

Fast macro to traverse the list. Call it first with copy of list header: it returns the first object and increments the passed list pointer. Call it with the same variable until it returns NULL.

#define	HTAssocList_nextObject(me) \
	((me) && ((me) = (me)->next) ? (me)->object : NULL)
#endif /* not HTASSOC_H */

@(#) $Id: HTAssoc.html,v 2.18 1999/04/18 20:17:44 frystyk Exp $