/*-------------------------------------------------------------------------
 *
 * pg_list.h
 *	  POSTGRES generic list package
 *
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 * $Id: pg_list.h,v 1.11 1999/02/22 05:26:47 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_LIST_H
#define PG_LIST_H

#include <nodes/nodes.h>

/* ----------------------------------------------------------------
 *						node definitions
 * ----------------------------------------------------------------
 */

/*----------------------
 *		Value node
 *----------------------
 */
typedef struct Value
{
	NodeTag		type;			/* tag appropriately (eg. T_String) */
	union ValUnion
	{
		char	   *str;		/* string */
		long		ival;
		double		dval;
	}			val;
} Value;

#define intVal(v)		(((Value *)v)->val.ival)
#define floatVal(v)		(((Value *)v)->val.dval)
#define strVal(v)		(((Value *)v)->val.str)


/*----------------------
 *		List node
 *----------------------
 */
typedef struct List
{
	NodeTag		type;
	union
	{
		void	   *ptr_value;
		int			int_value;
	}			elem;
	struct List *next;
} List;

#define    NIL			((List *) NULL)

/* ----------------
 *		accessor macros
 * ----------------
 */

/* anything that doesn't end in 'i' is assumed to be referring to the */
/* pointer version of the list (where it makes a difference)		  */
#define lfirst(l)								((l)->elem.ptr_value)
#define lnext(l)								((l)->next)
#define lsecond(l)								(lfirst(lnext(l)))

#define lfirsti(l)								((l)->elem.int_value)

/*
 * foreach -
 *	  a convenience macro which loops through the list
 */
#define foreach(_elt_,_list_)	\
	for(_elt_=_list_; _elt_!=NIL;_elt_=lnext(_elt_))


/*
 * function prototypes in nodes/list.c
 */
extern int	length(List *list);
extern List *nconc(List *list1, List *list2);
extern List *lcons(void *datum, List *list);
extern bool member(void *foo, List *bar);
extern Value *makeInteger(long i);
extern Value *makeFloat(double d);
extern Value *makeString(char *str);
extern List *makeList(void *elem,...);
extern List *lappend(List *list, void *obj);
extern List *lremove(void *elem, List *list);
extern void freeList(List *list);
extern List *LispRemove(void *elem, List *list);

extern void *nth(int n, List *l);
extern void set_nth(List *l, int n, void *elem);

List	   *lconsi(int datum, List *list);
List	   *lappendi(List *list, int datum);
extern bool intMember(int, List *);

extern int	nthi(int n, List *l);

extern List *set_difference(List *, List *);
extern List *set_differencei(List *, List *);
extern List *LispUnion(List *foo, List *bar);
extern List *LispUnioni(List *foo, List *bar);
extern bool same(List *foo, List *bar);

/* should be in nodes.h but needs List */

/* in copyfuncs.c */
extern List *listCopy(List *);

#endif	 /* PG_LIST_H */
