text: /*
   * Portions Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   * Portions Copyright (C) 2001  Internet Software Consortium.
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
   * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
   * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   *
   * Portions Copyright (C) 2001  Nominum, Inc.
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
   * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
   * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  /* $Id: sexpr.c,v 1.9 2007-08-28 07:20:43 tbox Exp $ */
  
  /*! \file */
  
  #include <config.h>
  
  #include <ctype.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include <isc/assertions.h>
  #include <isccc/sexpr.h>
  #include <isccc/util.h>
  
  static isccc_sexpr_t sexpr_t = { ISCCC_SEXPRTYPE_T, { NULL } };
  
  #define CAR(s)			(s)->value.as_dottedpair.car
  #define CDR(s)			(s)->value.as_dottedpair.cdr
  
  isccc_sexpr_t *
  isccc_sexpr_cons(isccc_sexpr_t *car, isccc_sexpr_t *cdr)
  {
  	isccc_sexpr_t *sexpr;
  
  	sexpr = malloc(sizeof(*sexpr));
  	if (sexpr == NULL)
  		return (NULL);
  	sexpr->type = ISCCC_SEXPRTYPE_DOTTEDPAIR;
  	CAR(sexpr) = car;
  	CDR(sexpr) = cdr;
  
  	return (sexpr);
  }
  
  isccc_sexpr_t *
  isccc_sexpr_tconst(void)
  {
  	return (&sexpr_t);
  }
  
  isccc_sexpr_t *
  isccc_sexpr_fromstring(const char *str)
  {
  	isccc_sexpr_t *sexpr;
  
  	sexpr = malloc(sizeof(*sexpr));
  	if (sexpr == NULL)
  		return (NULL);
  	sexpr->type = ISCCC_SEXPRTYPE_STRING;
  	sexpr->value.as_string = strdup(str);
  	if (sexpr->value.as_string == NULL) {
  		free(sexpr);
  		return (NULL);
  	}
  
  	return (sexpr);
  }
  
  isccc_sexpr_t *
  isccc_sexpr_frombinary(const isccc_region_t *region)
  {
  	isccc_sexpr_t *sexpr;
  	unsigned int region_size;
  
  	sexpr = malloc(sizeof(*sexpr));
  	if (sexpr == NULL)
  		return (NULL);
  	sexpr->type = ISCCC_SEXPRTYPE_BINARY;
  	region_size = REGION_SIZE(*region);
  	/*
  	 * We add an extra byte when we malloc so we can NUL terminate
  	 * the binary data.  This allows the caller to use it as a C
  	 * string.  It's up to the caller to ensure this is safe.  We don't
  	 * add 1 to the length of the binary region, because the NUL is
  	 * not part of the binary data.
  	 */
  	sexpr->value.as_region.rstart = malloc(region_size + 1);
  	if (sexpr->value.as_region.rstart == NULL) {
  		free(sexpr);
  		return (NULL);
  	}
  	sexpr->value.as_region.rend = sexpr->value.as_region.rstart +
  		region_size;
  	memcpy(sexpr->value.as_region.rstart, region->rstart, region_size);
  	/*
  	 * NUL terminate.
  	 */
  	sexpr->value.as_region.rstart[region_size] = '\0';
  
  	return (sexpr);
  }
  
  void
  isccc_sexpr_free(isccc_sexpr_t **sexprp)
  {
  	isccc_sexpr_t *sexpr;
  	isccc_sexpr_t *item;
  
  	sexpr = *sexprp;
  	if (sexpr == NULL)
  		return;
  	switch (sexpr->type) {
  	case ISCCC_SEXPRTYPE_STRING:
  		free(sexpr->value.as_string);
  		break;
  	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
  		item = CAR(sexpr);
  		if (item != NULL)
  			isccc_sexpr_free(&item);
  		item = CDR(sexpr);
  		if (item != NULL)
  			isccc_sexpr_free(&item);
  		break;
  	case ISCCC_SEXPRTYPE_BINARY:
  		free(sexpr->value.as_region.rstart);
  		break;
  	}
  	free(sexpr);
  
  	*sexprp = NULL;
  }
  
  static isc_boolean_t
  printable(isccc_region_t *r)
  {
  	unsigned char *curr;
  
  	curr = r->rstart;
  	while (curr != r->rend) {
  		if (!isprint(*curr))
  			return (ISC_FALSE);
  		curr++;
  	}
  
  	return (ISC_TRUE);
  }
  
  void
  isccc_sexpr_print(isccc_sexpr_t *sexpr, FILE *stream)
  {
  	isccc_sexpr_t *cdr;
  	unsigned int size, i;
  	unsigned char *curr;
  
  	if (sexpr == NULL) {
  		fprintf(stream, "nil");
  		return;
  	}
  
  	switch (sexpr->type) {
  	case ISCCC_SEXPRTYPE_T:
  		fprintf(stream, "t");
  		break;
  	case ISCCC_SEXPRTYPE_STRING:
  		fprintf(stream, "\"%s\"", sexpr->value.as_string);
  		break;
  	case ISCCC_SEXPRTYPE_DOTTEDPAIR:
  		fprintf(stream, "(");
  		do {
  			isccc_sexpr_print(CAR(sexpr), stream);
  			cdr = CDR(sexpr);
  			if (cdr != NULL) {
  				fprintf(stream, " ");
  				if (cdr->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
  					fprintf(stream, ". ");
  					isccc_sexpr_print(cdr, stream);
  					cdr = NULL;
  				}
  			}
  			sexpr = cdr;
  		} while (sexpr != NULL);
  		fprintf(stream, ")");
  		break;
  	case ISCCC_SEXPRTYPE_BINARY:
  		size = REGION_SIZE(sexpr->value.as_region);
  		curr = sexpr->value.as_region.rstart;
  		if (printable(&sexpr->value.as_region)) {
  			fprintf(stream, "'%.*s'", (int)size, curr);
  		} else {
  			fprintf(stream, "0x");
  			for (i = 0; i < size; i++)
  				fprintf(stream, "%02x", *curr++);
  		}
  		break;
  	default:
  		INSIST(0);
  	}
  }
  
  isccc_sexpr_t *
  isccc_sexpr_car(isccc_sexpr_t *list)
  {
  	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
  
  	return (CAR(list));
  }
  
  isccc_sexpr_t *
  isccc_sexpr_cdr(isccc_sexpr_t *list)
  {
  	REQUIRE(list->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
  
  	return (CDR(list));
  }
  
  void
  isccc_sexpr_setcar(isccc_sexpr_t *pair, isccc_sexpr_t *car)
  {
  	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
  
  	CAR(pair) = car;
  }
  
  void
  isccc_sexpr_setcdr(isccc_sexpr_t *pair, isccc_sexpr_t *cdr)
  {
  	REQUIRE(pair->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
  
  	CDR(pair) = cdr;
  }
  
  isccc_sexpr_t *
  isccc_sexpr_addtolist(isccc_sexpr_t **l1p, isccc_sexpr_t *l2)
  {
  	isccc_sexpr_t *last, *elt, *l1;
  
  	REQUIRE(l1p != NULL);
  	l1 = *l1p;
  	REQUIRE(l1 == NULL || l1->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
  
  	elt = isccc_sexpr_cons(l2, NULL);
  	if (elt == NULL)
  		return (NULL);
  	if (l1 == NULL) {
  		*l1p = elt;
  		return (elt);
  	}
  	for (last = l1; CDR(last) != NULL; last = CDR(last))
  		/* Nothing */;
  	CDR(last) = elt;
  
  	return (elt);
  }
  
  isc_boolean_t
  isccc_sexpr_listp(isccc_sexpr_t *sexpr)
  {
  	if (sexpr == NULL || sexpr->type == ISCCC_SEXPRTYPE_DOTTEDPAIR)
  		return (ISC_TRUE);
  	return (ISC_FALSE);
  }
  
  isc_boolean_t
  isccc_sexpr_emptyp(isccc_sexpr_t *sexpr)
  {
  	if (sexpr == NULL)
  		return (ISC_TRUE);
  	return (ISC_FALSE);
  }
  
  isc_boolean_t
  isccc_sexpr_stringp(isccc_sexpr_t *sexpr)
  {
  	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_STRING)
  		return (ISC_TRUE);
  	return (ISC_FALSE);
  }
  
  isc_boolean_t
  isccc_sexpr_binaryp(isccc_sexpr_t *sexpr)
  {
  	if (sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY)
  		return (ISC_TRUE);
  	return (ISC_FALSE);
  }
  
  char *
  isccc_sexpr_tostring(isccc_sexpr_t *sexpr)
  {
  	REQUIRE(sexpr != NULL &&
  		(sexpr->type == ISCCC_SEXPRTYPE_STRING ||
  		 sexpr->type == ISCCC_SEXPRTYPE_BINARY));
  	
  	if (sexpr->type == ISCCC_SEXPRTYPE_BINARY)
  		return ((char *)sexpr->value.as_region.rstart);
  	return (sexpr->value.as_string);
  }
  
  isccc_region_t *
  isccc_sexpr_tobinary(isccc_sexpr_t *sexpr)
  {
  	REQUIRE(sexpr != NULL && sexpr->type == ISCCC_SEXPRTYPE_BINARY);
  	return (&sexpr->value.as_region);
  }
  