array.c   [plain text]

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1982-2007 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Array processing routines
 *
 *   David Korn
 *   AT&T Labs
 *   dgk@research.att.com
 *
 */

#include	"defs.h"
#include	<stak.h>
#include	"name.h"

#define NUMSIZE	(4+(ARRAY_MAX>999)+(ARRAY_MAX>9999)+(ARRAY_MAX>99999))
#define is_associative(ap)	array_assoc((Namarr_t*)(ap))
#define array_setbit(cp, n)	(cp[(n)/CHAR_BIT] |= 1<<(((n)&(CHAR_BIT-1))))
#define array_clrbit(cp, n)	(cp[(n)/CHAR_BIT] &= ~(1<<(((n)&(CHAR_BIT-1)))))
#define array_isbit(cp, n)	(cp[(n)/CHAR_BIT] & 1<<(((n)&(CHAR_BIT-1))))
#define NV_CHILD		NV_EXPORT
#define Empty			((char*)(e_sptbnl+3))

struct index_array
{
        Namarr_t        header;
        int		cur;    /* index of current element */
        int		maxi;   /* maximum index for array */
	unsigned char	*bits;	/* bit array for child subscripts */
        union Value	val[1]; /* array of value holders */
};

struct assoc_array
{
	Namarr_t	header;
	Dt_t		*table;
	Namval_t	*pos;
	Namval_t	*nextpos;
	Namval_t	*cur;
};

/*
 * replace discipline with new one
 */
static void array_setptr(register Namval_t *np, struct index_array *old, struct index_array *new)
{
	register Namfun_t **fp = &np->nvfun;
	while(*fp && *fp!= &old->header.hdr)
		fp = &((*fp)->next);
	if(*fp)
	{
		new->header.hdr.next = (*fp)->next;
		*fp = &new->header.hdr;
	}
	else sfprintf(sfstderr,"discipline not replaced\n");
}

/*
 *   Calculate the amount of space to be allocated to hold an
 *   indexed array into which <maxi> is a legal index.  The number of
 *   elements that will actually fit into the array (> <maxi>
 *   but <= ARRAY_MAX) is returned.
 *
 */
static int	arsize(struct index_array *ap, register int maxi)
{
	if(ap && maxi < 2*ap->maxi)
		maxi = 2*ap->maxi;
	maxi = roundof(maxi,ARRAY_INCR);
	return (maxi>ARRAY_MAX?ARRAY_MAX:maxi);
}

static struct index_array *array_grow(Namval_t*, struct index_array*,int);

/* return index of highest element of an array */
int array_maxindex(Namval_t *np)
{
	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
	register int i = ap->maxi;
	if(is_associative(ap))
		return(-1);
	while(i>0 && ap->val[--i].cp==0);
	return(i+1);
}

static union Value *array_getup(Namval_t *np, Namarr_t *arp)
{
	register struct index_array *ap = (struct index_array*)arp;
	register union Value *up;
	if(!nv_isarray(np))
		return(&np->nvalue);
	if(is_associative(ap))
		up = (union Value*)((*arp->fun)(np,NIL(char*),0));
	else
	{
		if(ap->cur >= ap->maxi)
			errormsg(SH_DICT,ERROR_exit(1),e_subscript,nv_name(np));
		up = &(ap->val[ap->cur]);
	}
	return(up);
}

/*
 * Get the Value pointer for an array.
 * Delete space as necessary if flag is ARRAY_DELETE
 * After the lookup is done the last @ or * subscript is incremented
 */
static Namval_t *array_find(Namval_t *np,Namarr_t *arp, int flag)
{
	register struct index_array *ap = (struct index_array*)arp;
	register union Value	*up;
	Namval_t		*mp;
	int			wasundef;
	if(wasundef = ap->header.nelem&ARRAY_UNDEF)
	{
		ap->header.nelem &= ~ARRAY_UNDEF;
		/* delete array is the same as delete array[@] */
		if(flag&ARRAY_DELETE)
		{
			nv_putsub(np, NIL(char*), ARRAY_SCAN);
			ap->header.nelem |= ARRAY_SCAN;
		}
		else /* same as array[0] */
		{
			if(is_associative(ap))
				(*ap->header.fun)(np,"0",flag==ARRAY_ASSIGN?NV_AADD:0);
			else
				ap->cur = 0;
		}
	}
	if(is_associative(ap))
	{
		mp = (Namval_t*)((*arp->fun)(np,NIL(char*),NV_ACURRENT));
		if(!mp)
			up = (union Value*)&mp;
		else if(nv_isattr(mp,NV_CHILD))
		{
			if(wasundef && nv_isarray(mp->nvalue.np))
				nv_putsub(mp->nvalue.np,NIL(char*),ARRAY_UNDEF);
			return(mp->nvalue.np);
		}
		else
			up =  &mp->nvalue;
	}
	else
	{
		if(!(ap->header.nelem&ARRAY_SCAN) && ap->cur >= ap->maxi)
			ap = array_grow(np, ap, (int)ap->cur);
		if(ap->cur>=ap->maxi)
			errormsg(SH_DICT,ERROR_exit(1),e_subscript,nv_name(np));
		up = &(ap->val[ap->cur]);
		if(up->np && array_isbit(ap->bits,ap->cur))
		{
			if(wasundef && nv_isarray(up->np))
				nv_putsub(up->np,NIL(char*),ARRAY_UNDEF);
			return(up->np);
		}
	}
	np->nvalue.cp = up->cp;
	if(!up->cp)
	{
		if(flag!=ARRAY_ASSIGN)
			return(0);
		ap->header.nelem++;
	}
	return(np);
}

static Namfun_t *array_clone(Namval_t *np, Namval_t *mp, int flags, Namfun_t *fp)
{
	Namarr_t		*ap = (Namarr_t*)fp;
	Namval_t		*nq, *mq;
	char			*name, *sub=0;
	int			nelem = ap->nelem,offset=staktell();
	struct index_array	*aq, *ar;
	if(nelem&ARRAY_NOCLONE)
		return(0);
	if(array_assoc(ap))
		nv_setarray(mp,ap->fun);
	else
	{
		nv_putsub(mp,NIL(char*),ap->nelem);
		if(aq=(struct index_array*)nv_arrayptr(mp))
			aq->bits =  (unsigned char*)&aq->val[aq->maxi];
	}
	if(!(nelem&(ARRAY_SCAN|ARRAY_UNDEF)) && (sub=nv_getsub(np)))
		sub = strdup(sub);
	ar = (struct index_array*)ap;
	nv_onattr(mp,nv_isattr(np,NV_INTEGER|NV_UTOL|NV_LTOU|NV_LJUST|NV_RJUST|NV_ZFILL|NV_BINARY));
	nv_putsub(np,NIL(char*),ARRAY_SCAN);
	do
	{
	        if(array_assoc(ap))
			name = (char*)((*ap->fun)(np,NIL(char*),NV_ANAME));
		else
			name = nv_getsub(np);
		nv_putsub(mp,name,ARRAY_ADD);
		if((!array_assoc(ap) &&  array_isbit(ar->bits,ar->cur) && (nq=np)) ||
			(array_assoc(ap) && (nq = (Namval_t*)((*ap->fun)(np,NIL(char*),NV_ACURRENT))) && nv_isattr(nq, NV_CHILD)))
		{
			sfprintf(stkstd,"%s[%s]",nv_name(mp),name);
			stakputc(0);
			mq = nv_search(stakptr(offset), sh.var_tree, NV_ADD);
			stakseek(offset);
			if(mq)
			{
				nv_clone(nq->nvalue.np,mq,0);
				if(array_assoc(ap))
				{
					nq = (Namval_t*)((*ap->fun)(mp,NIL(char*),NV_ACURRENT));
					nq->nvalue.np = mp;
					nv_onattr(nq,NV_CHILD);
				}
				else if(aq)
				{
					array_setbit(aq->bits,aq->cur);
					aq->val[aq->cur].np = mq;
				}
			}
		}
		else if(nv_isattr(np,NV_INTEGER))
		{
			Sfdouble_t d= nv_getnum(np);
			nv_putval(mp,(char*)&d,NV_LDOUBLE);
		}
		else
			nv_putval(mp,nv_getval(np),NV_RDONLY);
	}
	while(nv_nextsub(np));
	if(sub)
	{
		nv_putsub(np,sub,0L);
		free((void*)sub);
	}
	ap->nelem = nelem;
	((Namarr_t*)mp->nvfun)->nelem = nelem;
	return(nv_stack(mp,(Namfun_t*)0));
}

static char *array_getval(Namval_t *np, Namfun_t *disc)
{
	register Namarr_t *ap = (Namarr_t*)disc;
	register Namval_t *mp;
	if((mp=array_find(np,ap,ARRAY_LOOKUP))!=np)
		return(mp?nv_getval(mp):0);
	return(nv_getv(np,&ap->hdr));
}

static Sfdouble_t array_getnum(Namval_t *np, Namfun_t *disc)
{
	register Namarr_t *ap = (Namarr_t*)disc;
	register Namval_t *mp;
	if((mp=array_find(np,ap,ARRAY_LOOKUP))!=np)
		return(mp?nv_getnum(mp):0);
	return(nv_getn(np,&ap->hdr));
}

static void array_putval(Namval_t *np, const char *string, int flags, Namfun_t *dp)
{
	register Namarr_t	*ap = (Namarr_t*)dp;
	register union Value	*up;
	register Namval_t	*mp;
	register struct index_array *aq = (struct index_array*)ap;
	do
	{
		mp = array_find(np,ap,string?ARRAY_ASSIGN:ARRAY_DELETE);
		if(mp && mp!=np)
			nv_putval(mp, string, flags);
		if(!string)
		{
			if(mp)
			{
				if(mp!=np)
				{
					dtdelete(sh.var_tree,(void*)mp);
					free((void*)mp);
				}
				if(is_associative(ap))
					(*ap->fun)(np,NIL(char*),NV_ADELETE);
				else if(mp!=np)
				{
					array_clrbit(aq->bits,aq->cur);
					aq->val[aq->cur].cp = 0;
				}
				ap->nelem--;
			}
			if(array_elem(ap)==0 && ((ap->nelem&ARRAY_SCAN) || !is_associative(ap)))
			{
				if(is_associative(ap))
					(*ap->fun)(np, NIL(char*), NV_AFREE);
				nv_offattr(np,NV_ARRAY);
			}
			if(!mp || mp!=np)
				continue;
		}
		/* prevent empty string from being deleted */
		if(np->nvalue.cp == Empty)
			np->nvalue.cp = 0;
		nv_putv(np,string,flags,&ap->hdr);
		up = array_getup(np,ap);
		up->cp = np->nvalue.cp;
	}
	while(!string && nv_nextsub(np));
	if(!string && !nv_isattr(np,NV_ARRAY))
	{
		Namfun_t *nfp;
		if(nfp = nv_disc(np,(Namfun_t*)ap,NV_POP))
			free((void*)nfp);
		if(np->nvalue.cp==Empty)
			np->nvalue.cp = 0;
	}
}

static const Namdisc_t array_disc =
{
	sizeof(Namarr_t),
	array_putval,
	array_getval,
	array_getnum,
	0,
	0,
	array_clone
};

/*
 *        Increase the size of the indexed array of elements in <arp>
 *        so that <maxi> is a legal index.  If <arp> is 0, an array
 *        of the required size is allocated.  A pointer to the 
 *        allocated Namarr_t structure is returned.
 *        <maxi> becomes the current index of the array.
 */
static struct index_array *array_grow(Namval_t *np, register struct index_array *arp,int maxi)
{
	register struct index_array *ap;
	register int i=0;
	register int newsize = arsize(arp,maxi+1);
	if (maxi >= ARRAY_MAX)
		errormsg(SH_DICT,ERROR_exit(1),e_subscript, fmtbase((long)maxi,10,0));
	ap = new_of(struct index_array,(newsize-1)*sizeof(union Value*)+newsize/CHAR_BIT);
	memset((void*)ap,0,sizeof(*ap));
	ap->maxi = newsize;
	ap->cur = maxi;
	ap->bits =  (unsigned char*)&ap->val[newsize];
	memset(ap->bits, 0, newsize/CHAR_BIT);
	if(arp)
	{
		ap->header = arp->header;
		for(;i < arp->maxi;i++)
			ap->val[i].cp = arp->val[i].cp;
		memcpy(ap->bits, arp->bits, (arp->maxi/CHAR_BIT));
		array_setptr(np,arp,ap);
		free((void*)arp);
	}
	else
	{
		ap->header.fun = 0;
		if((ap->val[0].cp=np->nvalue.cp))
			i++;
		else if(nv_hasdisc(np,&array_disc))
		{
			Namval_t *mp;
			int offset = staktell();
			sfprintf(stkstd,"%s[0]",nv_name(np));
			stakputc(0);
			mp = nv_search(stakptr(offset), sh.var_tree, NV_ADD);
			stakseek(offset);
			if(mp && nv_isnull(mp))
			{
				nv_clone(np,mp,0);
				ap->val[0].np = mp;
				array_setbit(ap->bits,0);
			}
			i++;
		}
		else if(nv_isattr(np,NV_INTEGER))
		{
			Sfdouble_t d= nv_getnum(np);
			i++;
		}
		ap->header.nelem = i;
		ap->header.hdr.nofree = 1;
		ap->header.hdr.disc = &array_disc;
		nv_disc(np,(Namfun_t*)ap, NV_LAST);
	}
	for(;i < newsize;i++)
		ap->val[i].cp = 0;
	return(ap);
}

Namarr_t *nv_arrayptr(register Namval_t *np)
{
	if(nv_isattr(np,NV_ARRAY))
		return((Namarr_t*)nv_hasdisc(np, &array_disc));
	return(0);
}

/*
 * Verify that argument is an indexed array and convert to associative,
 * freeing relevant storage
 */
static Namarr_t *nv_changearray(Namval_t *np, void *(*fun)(Namval_t*,const char*,int))
{
	register Namarr_t *ap;
	char numbuff[NUMSIZE+1];
	unsigned dot, digit, n;
	union Value *up;
	struct index_array *save_ap;
	register char *string_index=&numbuff[NUMSIZE];
	numbuff[NUMSIZE]='\0';

	if(!fun || !(ap = nv_arrayptr(np)) || is_associative(ap))
		return(NIL(Namarr_t*));

	nv_stack(np,&ap->hdr);
	save_ap = (struct index_array*)nv_stack(np,0);
	ap = (Namarr_t*)((*fun)(np, NIL(char*), NV_AINIT));
	ap->nelem = 0;
	ap->fun = fun;
	nv_onattr(np,NV_ARRAY);

	for(dot = 0; dot < (unsigned)save_ap->maxi; dot++)
	{
		if(save_ap->val[dot].cp)
		{
			if ((digit = dot)== 0)
				*--string_index = '0';
			else while( n = digit )
			{
				digit /= 10;
				*--string_index = '0' + (n-10*digit);
			}
			nv_putsub(np, string_index, ARRAY_ADD);
			up = (union Value*)((*ap->fun)(np,NIL(char*),0));
			ap->nelem++;
			up->cp = save_ap->val[dot].cp;
			save_ap->val[dot].cp = 0;
		}
		string_index = &numbuff[NUMSIZE];
	}
	free((void*)save_ap);
	return(ap);
}

/*
 * set the associative array processing method for node <np> to <fun>
 * The array pointer is returned if sucessful.
 */
Namarr_t *nv_setarray(Namval_t *np, void *(*fun)(Namval_t*,const char*,int))
{
	register Namarr_t *ap;
	char *value;
	if(fun && (ap = nv_arrayptr(np)))
	{
		/*
		 * if it's already an indexed array, convert to 
		 * associative structure
		 */
		if(!is_associative(ap))
			ap = nv_changearray(np, fun);
		return(ap);
	}
	value = nv_getval(np);
	if(fun && !ap && (ap = (Namarr_t*)((*fun)(np, NIL(char*), NV_AINIT))))
	{
		/* check for preexisting initialization and save */
		ap->nelem = 0;
		ap->fun = fun;
		nv_onattr(np,NV_ARRAY);
		if(value)
		{
			nv_putsub(np, "0", ARRAY_ADD);
			nv_putval(np, value, 0);
		}
		return(ap);
	}
	return(NIL(Namarr_t*));
}

/*
 * move parent subscript into child
 */
Namval_t *nv_arraychild(Namval_t *np, Namval_t *nq, int c)
{
	register Namarr_t *ap = nv_arrayptr(np);
	union Value *up;
	if(!nq)
		return(ap?array_find(np,ap, ARRAY_LOOKUP):0);
	if(!ap)
	{
		nv_putsub(np, NIL(char*), ARRAY_FILL);
		ap = nv_arrayptr(np);
	}
	if(!(up = array_getup(np,ap)))
		return((Namval_t*)0);
	np->nvalue.cp = up->cp;
	ap->nelem |= ARRAY_NOCLONE;
	nv_clone(np, nq, NV_NODISC);
	nv_offattr(nq,NV_ARRAY);
	ap->nelem &= ~ARRAY_NOCLONE;
	if(ap->fun)
	{
		if(!(up->np = (Namval_t*)((*ap->fun)(np,NIL(char*),NV_ACURRENT))))
			nv_putsub(np,"0",ARRAY_ADD);
		up->np = (Namval_t*)((*ap->fun)(np,NIL(char*),NV_ACURRENT));
		nv_onattr(up->np, NV_CHILD);
		(up->np)->nvalue.np = nq;
	}
	else
	{
		struct index_array *aq = (struct index_array*)ap;
		array_setbit(aq->bits,aq->cur);
		up->np = nq;
	}
	if(c=='.')
		nv_setvtree(nq);
	return(nq);
}

/*
 * This routine sets subscript of <np> to the next element, if any.
 * The return value is zero, if there are no more elements
 * Otherwise, 1 is returned.
 */
int nv_nextsub(Namval_t *np)
{
	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
	register unsigned dot;
	if(!ap || !(ap->header.nelem&ARRAY_SCAN))
		return(0);
	if(is_associative(ap))
	{
		Namval_t	*nq;
		if(nq=(Namval_t*)(*ap->header.fun)(np,NIL(char*),NV_ANEXT))
		{
			if(nv_isattr(nq,NV_CHILD))
				nv_putsub(nq->nvalue.np,NIL(char*),ARRAY_UNDEF);
			return(1);
		}
		ap->header.nelem &= ~(ARRAY_SCAN|ARRAY_NOCHILD);
		return(0);
	}
	for(dot=ap->cur+1; dot <  (unsigned)ap->maxi; dot++)
	{
		if(ap->val[dot].cp)
		{
			ap->cur = dot;
			if(array_isbit(ap->bits, dot))
			{
				
				if(ap->header.nelem&ARRAY_NOCHILD)
					continue;
				nv_putsub(ap->val[dot].np,NIL(char*),ARRAY_UNDEF);
			}
			return(1);
		}
	}
	ap->header.nelem &= ~(ARRAY_SCAN|ARRAY_NOCHILD);
	ap->cur = 0;
	return(0);
}

/*
 * Set an array subscript for node <np> given the subscript <sp>
 * An array is created if necessary.
 * <mode> can be a number, plus or more of symbolic constants
 *    ARRAY_SCAN, ARRAY_UNDEF, ARRAY_ADD
 * The node pointer is returned which can be NULL if <np> is
 *    not already array and the ARRAY_ADD bit of <mode> is not set.
 * ARRAY_FILL sets the specified subscript to the empty string when
 *   ARRAY_ADD is specified and there is no value or sets all
 * the elements up to the number specified if ARRAY_ADD is not specified
 */
Namval_t *nv_putsub(Namval_t *np,register char *sp,register long mode)
{
	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
	register int size = (mode&ARRAY_MASK);
	if(!ap || !ap->header.fun)
	{
		if(sp)
			size = (int)sh_arith((char*)sp);
		if(size >= ARRAY_MAX || (size < 0))
		{
			errormsg(SH_DICT,ERROR_exit(1),e_subscript, nv_name(np));
			return(NIL(Namval_t*));
		}
		if(!ap || size>=ap->maxi)
		{
			if(size==0 && !(mode&ARRAY_FILL))
				return(NIL(Namval_t*));
			if(sh.subshell)
				np = sh_assignok(np,1);
			ap = array_grow(np, ap,size);
			nv_onattr(np,NV_ARRAY);
		}
		ap->header.nelem &= ~ARRAY_UNDEF;
		ap->header.nelem |= (mode&(ARRAY_SCAN|ARRAY_NOCHILD|ARRAY_UNDEF));
		ap->cur = size;
		if((mode&ARRAY_SCAN) && !ap->val[size].cp && !nv_nextsub(np))
			np = 0;
		if(mode&ARRAY_FILL)
		{
			if(!(mode&ARRAY_ADD))
			{
				int n;
				for(n=0; n < size; n++)
				{
					if(!ap->val[n].cp)
						ap->val[n].cp = Empty;
				}
				ap->header.nelem = n|(ap->header.nelem&(ARRAY_SCAN|ARRAY_UNDEF));
				if(n=ap->maxi-ap->maxi)
					memset(&ap->val[size],0,n*sizeof(union Value));
			}
			else if(!ap->val[size].cp)
			{
				if(sh.subshell)
					np = sh_assignok(np,1);
				ap->val[size].cp = Empty;
				ap->header.nelem++;
			}
		}
		else if(!(mode&ARRAY_SCAN))
		{
			ap->header.nelem &= ~ARRAY_SCAN;
			if(array_isbit(ap->bits,size))
				nv_putsub(ap->val[size].np,NIL(char*),ARRAY_UNDEF);
		}
		return((Namval_t*)np);
	}
	ap->header.nelem &= ~ARRAY_UNDEF;
	if(!(mode&ARRAY_FILL))
		ap->header.nelem &= ~ARRAY_SCAN;
	ap->header.nelem |= (mode&(ARRAY_SCAN|ARRAY_NOCHILD|ARRAY_UNDEF));
	if(sp)
	{
		union Value *up;
		if(mode&ARRAY_SETSUB)
		{
			(*ap->header.fun)(np, sp, NV_ASETSUB);
			return(np);
		}
		up = (union Value*)(*ap->header.fun)(np, sp, (mode&ARRAY_ADD)?NV_AADD:0);
		if(up && !up->cp && (mode&ARRAY_ADD) && (mode&ARRAY_FILL))
		{
			if(sh.subshell)
				np = sh_assignok(np,1);
			up->cp = Empty;
			ap->header.nelem++;
		}
	}
	else if(mode&ARRAY_SCAN)
		(*ap->header.fun)(np,(char*)np,0);
	else if(mode&ARRAY_UNDEF)
		(*ap->header.fun)(np, "",0);
	if((mode&ARRAY_SCAN) && !nv_nextsub(np))
		np = 0;
	return(np);
}

/*
 * process an array subscript for node <np> given the subscript <cp>
 * returns pointer to character after the subscript
 */
char *nv_endsubscript(Namval_t *np, register char *cp, int mode)
{
	register int count=1, quoted=0, c;
	register char *sp = cp+1;
	/* first find matching ']' */
	while(count>0 && (c= *++cp))
	{
		if(c=='\\' && (!(mode&NV_SUBQUOTE) || (c=cp[1])=='[' || c==']' || c=='\\' || c=='*' || c=='@'))
		{
			quoted=1;
			cp++;
		}
		else if(c=='[')
			count++;
		else if(c==']')
			count--;
	}
	*cp = 0;
	if(quoted)
	{
		/* strip escape characters */
		count = staktell();
		stakwrite(sp,1+cp-sp);
		sh_trim(sp=stakptr(count));
	}
	if(mode && np)
		nv_putsub(np, sp, ARRAY_ADD|(cp[1]?ARRAY_FILL:mode&ARRAY_FILL));
	if(quoted)
		stakseek(count);
	*cp++ = c;
	return(cp);
}


Namval_t *nv_opensub(Namval_t* np)
{
	register struct index_array *ap = (struct index_array*)nv_arrayptr(np);
	if(ap && is_associative(ap))
		return((Namval_t*)((*ap->header.fun)(np,NIL(char*),NV_ACURRENT)));
	return(NIL(Namval_t*));
}

char	*nv_getsub(Namval_t* np)
{
	static char numbuff[NUMSIZE];
	register struct index_array *ap;
	register unsigned dot, n;
	register char *cp = &numbuff[NUMSIZE];
	if(!np || !(ap = (struct index_array*)nv_arrayptr(np)))
		return(NIL(char*));
	if(is_associative(ap))
		return((char*)((*ap->header.fun)(np,NIL(char*),NV_ANAME)));
	if((dot = ap->cur)==0)
		*--cp = '0';
	else while(n=dot)
	{
		dot /= 10;
		*--cp = '0' + (n-10*dot);
	}
	return(cp);
}

/*
 * If <np> is an indexed array node, the current subscript index
 * returned, otherwise returns -1
 */
int nv_aindex(register Namval_t* np)
{
	Namarr_t *ap = nv_arrayptr(np);
	if(!ap || is_associative(ap))
		return(-1);
	return(((struct index_array*)(ap))->cur&ARRAY_MASK);
}


/*
 *  This is the default implementation for associate arrays
 */
void *nv_associative(register Namval_t *np,const char *sp,int mode)
{
	register struct assoc_array *ap = (struct assoc_array*)nv_arrayptr(np);
	register int type;
	switch(mode)
	{
	    case NV_AINIT:
		if(ap = (struct assoc_array*)calloc(1,sizeof(struct assoc_array)))
		{
			ap->table = dtopen(&_Nvdisc,Dtbag);
			ap->cur = 0;
			ap->pos = 0;
			ap->header.hdr.disc = &array_disc;
			ap->header.hdr.nofree = 1;
			nv_disc(np,(Namfun_t*)ap, NV_LAST);
		}
		return((void*)ap);
	    case NV_ADELETE:
		if(ap->cur)
		{
			if(nv_isattr(ap->cur,NV_NOFREE))
				nv_offattr(ap->cur,NV_NOFREE);
			else
			{
				dtdelete(ap->table,(void*)ap->cur);
				free((void*)ap->cur);
				ap->cur = 0;
			}
		}
		return((void*)ap);
	    case NV_AFREE:
		ap->pos = 0;
		dtclose(ap->table);
		return((void*)ap);
	    case NV_ANEXT:
		if(!ap->pos)
		{
			if(!(ap->pos=ap->cur))
				ap->pos = (Namval_t*)dtfirst(ap->table);
		}
		else
			ap->pos = ap->nextpos;
		for(;ap->cur=ap->pos; ap->pos=ap->nextpos)
		{
			ap->nextpos = (Namval_t*)dtnext(ap->table,ap->pos);
			if(ap->cur->nvalue.cp)
			{
				if((ap->header.nelem&ARRAY_NOCHILD) && nv_isattr(ap->cur,NV_CHILD))
					continue;
				return((void*)ap->cur);
			}
		}
		return(NIL(void*));
	    case NV_ASETSUB:
		ap->cur = (Namval_t*)sp;
		/* FALL THROUGH*/
	    case NV_ACURRENT:
		return((void*)ap->cur);
	    case NV_ANAME:
		if(ap->cur)
			return((void*)nv_name(ap->cur));
		return(NIL(void*));
	    default:
		if(sp)
		{
			if(sp==(char*)np)
			{
				ap->cur = 0;
				return(0);
			}
			else if(!(ap->header.nelem&ARRAY_SCAN))
				ap->pos = 0;
			type = nv_isattr(np,NV_PUBLIC&~(NV_ARRAY|NV_CHILD));
			if((np=nv_search(sp,ap->table,mode?NV_ADD:0)) && nv_isnull(np))
				nv_onattr(np,type);
			ap->cur = np;
		}
		if(ap->cur)
			return((void*)(&ap->cur->nvalue));
		else
			return((void*)(&ap->cur));
	}
}

/*
 * Assign values to an array
 */
void nv_setvec(register Namval_t *np,int append,register int argc,register char *argv[])
{
	int arg0=0;
	struct index_array *ap=0;
	if(nv_isarray(np))
	{
		ap = (struct index_array*)nv_arrayptr(np);
		if(ap && is_associative(ap))
			errormsg(SH_DICT,ERROR_exit(1),"cannot append index array to associate array %s",nv_name(np));
	}
	if(append)
	{
		if(ap)
		{
			arg0 = ap->maxi;
			while(--arg0>0 && ap->val[arg0].cp==0);
			arg0++;
		}
		else if(!nv_isnull(np))
			arg0=1;
	}
	while(--argc >= 0)
	{
		if((argc+arg0)>0  || nv_isattr(np,NV_ARRAY))
			nv_putsub(np,NIL(char*),(long)argc+arg0);
		nv_putval(np,argv[argc],0);
	}
}