MFC: r263648, r264789, r266636

This brings:
- schema validation
- xpath-like interface for ucl objects

Adapt pkg(7) to the new libucl API

9 files changed, 2328 insertions, 221 deletions

diff --git a/contrib/libucl/src/Makefile.am b/contrib/libucl/src/Makefile.am
new file mode 100644
index 0000000..76391cd
--- /dev/null
+++ b/contrib/libucl/src/Makefile.am
@@ -0,0 +1,25 @@
+libucl_common_cflags=	-I$(top_srcdir)/src \
+			-I$(top_srcdir)/include \
+			-I$(top_srcdir)/uthash \
+			-Wall -W -Wno-unused-parameter -Wno-pointer-sign
+lib_LTLIBRARIES=	libucl.la
+libucl_la_SOURCES=	ucl_emitter.c \
+					ucl_hash.c \
+					ucl_parser.c \
+					ucl_schema.c \
+					ucl_util.c \
+					xxhash.c
+libucl_la_CFLAGS=	$(libucl_common_cflags) \
+					@CURL_CFLAGS@
+libucl_la_LDFLAGS = -version-info @SO_VERSION@
+libucl_la_LIBADD=	@LIBFETCH_LIBS@ \
+					@LIBCRYPTO_LIB@ \
+					@LIBREGEX_LIB@ \
+					@CURL_LIBS@
+
+include_HEADERS=	$(top_srcdir)/include/ucl.h
+noinst_HEADERS=	ucl_internal.h \
+				xxhash.h \
+				ucl_hash.h \
+				ucl_chartable.h \
+				tree.h
diff --git a/contrib/libucl/src/tree.h b/contrib/libucl/src/tree.h
new file mode 100644
index 0000000..cee9373
--- /dev/null
+++ b/contrib/libucl/src/tree.h
@@ -0,0 +1,212 @@
+/* tree.h -- AVL trees (in the spirit of BSD's 'queue.h')	-*- C -*-	*/
+
+/* Copyright (c) 2005 Ian Piumarta
+ * 
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the 'Software'), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * provided that the above copyright notice(s) and this permission notice appear
+ * in all copies of the Software and that both the above copyright notice(s) and
+ * this permission notice appear in supporting documentation.
+ *
+ * THE SOFTWARE IS PROVIDED 'AS IS'.  USE ENTIRELY AT YOUR OWN RISK.
+ */
+
+/* This file defines an AVL balanced binary tree [Georgii M. Adelson-Velskii and
+ * Evgenii M. Landis, 'An algorithm for the organization of information',
+ * Doklady Akademii Nauk SSSR, 146:263-266, 1962 (Russian).  Also in Myron
+ * J. Ricci (trans.), Soviet Math, 3:1259-1263, 1962 (English)].
+ * 
+ * An AVL tree is headed by pointers to the root node and to a function defining
+ * the ordering relation between nodes.  Each node contains an arbitrary payload
+ * plus three fields per tree entry: the depth of the subtree for which it forms
+ * the root and two pointers to child nodes (singly-linked for minimum space, at
+ * the expense of direct access to the parent node given a pointer to one of the
+ * children).  The tree is rebalanced after every insertion or removal.  The
+ * tree may be traversed in two directions: forward (in-order left-to-right) and
+ * reverse (in-order, right-to-left).
+ * 
+ * Because of the recursive nature of many of the operations on trees it is
+ * necessary to define a number of helper functions for each type of tree node.
+ * The macro TREE_DEFINE(node_tag, entry_name) defines these functions with
+ * unique names according to the node_tag.  This macro should be invoked,
+ * thereby defining the necessary functions, once per node tag in the program.
+ * 
+ * For details on the use of these macros, see the tree(3) manual page.
+ */
+
+#ifndef __tree_h
+#define __tree_h
+
+
+#define TREE_DELTA_MAX	1
+
+#define TREE_ENTRY(type)			\
+  struct {					\
+    struct type	*avl_left;			\
+    struct type	*avl_right;			\
+    int		 avl_height;			\
+  }
+
+#define TREE_HEAD(name, type)				\
+  struct name {						\
+    struct type *th_root;				\
+    int  (*th_cmp)(struct type *lhs, struct type *rhs);	\
+  }
+
+#define TREE_INITIALIZER(cmp) { 0, cmp }
+
+#define TREE_DELTA(self, field)								\
+  (( (((self)->field.avl_left)  ? (self)->field.avl_left->field.avl_height  : 0))	\
+   - (((self)->field.avl_right) ? (self)->field.avl_right->field.avl_height : 0))
+
+/* Recursion prevents the following from being defined as macros. */
+
+#define TREE_DEFINE(node, field)									\
+													\
+  struct node *TREE_BALANCE_##node##_##field(struct node *);						\
+													\
+  struct node *TREE_ROTL_##node##_##field(struct node *self)						\
+  {													\
+    struct node *r= self->field.avl_right;								\
+    self->field.avl_right= r->field.avl_left;								\
+    r->field.avl_left= TREE_BALANCE_##node##_##field(self);						\
+    return TREE_BALANCE_##node##_##field(r);								\
+  }													\
+													\
+  struct node *TREE_ROTR_##node##_##field(struct node *self)						\
+  {													\
+    struct node *l= self->field.avl_left;								\
+    self->field.avl_left= l->field.avl_right;								\
+    l->field.avl_right= TREE_BALANCE_##node##_##field(self);						\
+    return TREE_BALANCE_##node##_##field(l);								\
+  }													\
+													\
+  struct node *TREE_BALANCE_##node##_##field(struct node *self)						\
+  {													\
+    int delta= TREE_DELTA(self, field);									\
+													\
+    if (delta < -TREE_DELTA_MAX)									\
+      {													\
+	if (TREE_DELTA(self->field.avl_right, field) > 0)						\
+	  self->field.avl_right= TREE_ROTR_##node##_##field(self->field.avl_right);			\
+	return TREE_ROTL_##node##_##field(self);							\
+      }													\
+    else if (delta > TREE_DELTA_MAX)									\
+      {													\
+	if (TREE_DELTA(self->field.avl_left, field) < 0)						\
+	  self->field.avl_left= TREE_ROTL_##node##_##field(self->field.avl_left);			\
+	return TREE_ROTR_##node##_##field(self);							\
+      }													\
+    self->field.avl_height= 0;										\
+    if (self->field.avl_left && (self->field.avl_left->field.avl_height > self->field.avl_height))	\
+      self->field.avl_height= self->field.avl_left->field.avl_height;					\
+    if (self->field.avl_right && (self->field.avl_right->field.avl_height > self->field.avl_height))	\
+      self->field.avl_height= self->field.avl_right->field.avl_height;					\
+    self->field.avl_height += 1;									\
+    return self;											\
+  }													\
+													\
+  struct node *TREE_INSERT_##node##_##field								\
+    (struct node *self, struct node *elm, int (*compare)(struct node *lhs, struct node *rhs))		\
+  {													\
+    if (!self)												\
+      return elm;											\
+    if (compare(elm, self) < 0)										\
+      self->field.avl_left= TREE_INSERT_##node##_##field(self->field.avl_left, elm, compare);		\
+    else												\
+      self->field.avl_right= TREE_INSERT_##node##_##field(self->field.avl_right, elm, compare);		\
+    return TREE_BALANCE_##node##_##field(self);								\
+  }													\
+													\
+  struct node *TREE_FIND_##node##_##field								\
+    (struct node *self, struct node *elm, int (*compare)(struct node *lhs, struct node *rhs))		\
+  {													\
+    if (!self)												\
+      return 0;												\
+    if (compare(elm, self) == 0)									\
+      return self;											\
+    if (compare(elm, self) < 0)										\
+      return TREE_FIND_##node##_##field(self->field.avl_left, elm, compare);				\
+    else												\
+      return TREE_FIND_##node##_##field(self->field.avl_right, elm, compare);				\
+  }													\
+													\
+  struct node *TREE_MOVE_RIGHT(struct node *self, struct node *rhs)					\
+  {													\
+    if (!self)												\
+      return rhs;											\
+    self->field.avl_right= TREE_MOVE_RIGHT(self->field.avl_right, rhs);					\
+    return TREE_BALANCE_##node##_##field(self);								\
+  }													\
+													\
+  struct node *TREE_REMOVE_##node##_##field								\
+    (struct node *self, struct node *elm, int (*compare)(struct node *lhs, struct node *rhs))		\
+  {													\
+    if (!self) return 0;										\
+													\
+    if (compare(elm, self) == 0)									\
+      {													\
+	struct node *tmp= TREE_MOVE_RIGHT(self->field.avl_left, self->field.avl_right);			\
+	self->field.avl_left= 0;									\
+	self->field.avl_right= 0;									\
+	return tmp;											\
+      }													\
+    if (compare(elm, self) < 0)										\
+      self->field.avl_left= TREE_REMOVE_##node##_##field(self->field.avl_left, elm, compare);		\
+    else												\
+      self->field.avl_right= TREE_REMOVE_##node##_##field(self->field.avl_right, elm, compare);		\
+    return TREE_BALANCE_##node##_##field(self);								\
+  }													\
+													\
+  void TREE_FORWARD_APPLY_ALL_##node##_##field								\
+    (struct node *self, void (*function)(struct node *node, void *data), void *data)			\
+  {													\
+    if (self)												\
+      {													\
+	TREE_FORWARD_APPLY_ALL_##node##_##field(self->field.avl_left, function, data);			\
+	function(self, data);										\
+	TREE_FORWARD_APPLY_ALL_##node##_##field(self->field.avl_right, function, data);			\
+      }													\
+  }													\
+													\
+  void TREE_REVERSE_APPLY_ALL_##node##_##field								\
+    (struct node *self, void (*function)(struct node *node, void *data), void *data)			\
+  {													\
+    if (self)												\
+      {													\
+	TREE_REVERSE_APPLY_ALL_##node##_##field(self->field.avl_right, function, data);			\
+	function(self, data);										\
+	TREE_REVERSE_APPLY_ALL_##node##_##field(self->field.avl_left, function, data);			\
+      }													\
+  }
+
+#define TREE_INSERT(head, node, field, elm)						\
+  ((head)->th_root= TREE_INSERT_##node##_##field((head)->th_root, (elm), (head)->th_cmp))
+
+#define TREE_FIND(head, node, field, elm)				\
+  (TREE_FIND_##node##_##field((head)->th_root, (elm), (head)->th_cmp))
+
+#define TREE_REMOVE(head, node, field, elm)						\
+  ((head)->th_root= TREE_REMOVE_##node##_##field((head)->th_root, (elm), (head)->th_cmp))
+
+#define TREE_DEPTH(head, field)			\
+  ((head)->th_root->field.avl_height)
+
+#define TREE_FORWARD_APPLY(head, node, field, function, data)	\
+  TREE_FORWARD_APPLY_ALL_##node##_##field((head)->th_root, function, data)
+
+#define TREE_REVERSE_APPLY(head, node, field, function, data)	\
+  TREE_REVERSE_APPLY_ALL_##node##_##field((head)->th_root, function, data)
+
+#define TREE_INIT(head, cmp) do {		\
+    (head)->th_root= 0;				\
+    (head)->th_cmp= (cmp);			\
+  } while (0)
+
+
+#endif /* __tree_h */
diff --git a/contrib/libucl/src/ucl_emitter.c b/contrib/libucl/src/ucl_emitter.c
index 51bb09a..04c3d4b 100644
--- a/contrib/libucl/src/ucl_emitter.c
+++ b/contrib/libucl/src/ucl_emitter.c
@@ -21,11 +21,19 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <float.h>
-#include <math.h>
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include "ucl.h"
 #include "ucl_internal.h"
 #include "ucl_chartable.h"
+#ifdef HAVE_FLOAT_H
+#include <float.h>
+#endif
+#ifdef HAVE_MATH_H
+#include <math.h>
+#endif
 
 /**
  * @file rcl_emitter.c
@@ -33,29 +41,29 @@
  */
 
 
-static void ucl_obj_write_json (ucl_object_t *obj,
+static void ucl_obj_write_json (const ucl_object_t *obj,
 		struct ucl_emitter_functions *func,
 		unsigned int tabs,
 		bool start_tabs,
 		bool compact);
-static void ucl_elt_write_json (ucl_object_t *obj,
+static void ucl_elt_write_json (const ucl_object_t *obj,
 		struct ucl_emitter_functions *func,
 		unsigned int tabs,
 		bool start_tabs,
 		bool compact);
-static void ucl_elt_write_config (ucl_object_t *obj,
+static void ucl_elt_write_config (const ucl_object_t *obj,
 		struct ucl_emitter_functions *func,
 		unsigned int tabs,
 		bool start_tabs,
 		bool is_top,
 		bool expand_array);
-static void ucl_elt_write_yaml (ucl_object_t *obj,
+static void ucl_elt_write_yaml (const ucl_object_t *obj,
 		struct ucl_emitter_functions *func,
 		unsigned int tabs,
 		bool start_tabs,
 		bool compact,
 		bool expand_array);
-static void ucl_elt_array_write_yaml (ucl_object_t *obj,
+static void ucl_elt_array_write_yaml (const ucl_object_t *obj,
 		struct ucl_emitter_functions *func,
 		unsigned int tabs,
 		bool start_tabs,
@@ -136,10 +144,10 @@ ucl_elt_string_write_json (const char *str, size_t size,
  * @param buf target buffer
  */
 static void
-ucl_elt_obj_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_obj_write_json (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool compact)
 {
-	ucl_object_t *cur;
+	const ucl_object_t *cur;
 	ucl_hash_iter_t it = NULL;
 
 	if (start_tabs) {
@@ -188,10 +196,10 @@ ucl_elt_obj_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf target buffer
  */
 static void
-ucl_elt_array_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_array_write_json (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool compact)
 {
-	ucl_object_t *cur = obj;
+	const ucl_object_t *cur = obj;
 
 	if (start_tabs) {
 		ucl_add_tabs (func, tabs, compact);
@@ -227,7 +235,7 @@ ucl_elt_array_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf buffer
  */
 static void
-ucl_elt_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_write_json (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool compact)
 {
 	bool flag;
@@ -287,10 +295,10 @@ ucl_elt_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf target buffer
  */
 static void
-ucl_obj_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_obj_write_json (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool compact)
 {
-	ucl_object_t *cur;
+	const ucl_object_t *cur;
 	bool is_array = (obj->next != NULL);
 
 	if (is_array) {
@@ -331,7 +339,8 @@ ucl_obj_write_json (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @return json output (should be freed after using)
  */
 static void
-ucl_object_emit_json (ucl_object_t *obj, bool compact, struct ucl_emitter_functions *func)
+ucl_object_emit_json (const ucl_object_t *obj, bool compact,
+		struct ucl_emitter_functions *func)
 {
 	ucl_obj_write_json (obj, func, 0, false, compact);
 }
@@ -342,10 +351,10 @@ ucl_object_emit_json (ucl_object_t *obj, bool compact, struct ucl_emitter_functi
  * @param buf target buffer
  */
 static void
-ucl_elt_obj_write_config (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_obj_write_config (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top)
 {
-	ucl_object_t *cur, *cur_obj;
+	const ucl_object_t *cur, *cur_obj;
 	ucl_hash_iter_t it = NULL;
 
 	if (start_tabs) {
@@ -394,10 +403,10 @@ ucl_elt_obj_write_config (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf target buffer
  */
 static void
-ucl_elt_array_write_config (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_array_write_config (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top)
 {
-	ucl_object_t *cur = obj;
+	const ucl_object_t *cur = obj;
 
 	if (start_tabs) {
 		ucl_add_tabs (func, tabs, false);
@@ -419,7 +428,7 @@ ucl_elt_array_write_config (ucl_object_t *obj, struct ucl_emitter_functions *fun
  * @param buf buffer
  */
 static void
-ucl_elt_write_config (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_write_config (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top, bool expand_array)
 {
 	bool flag;
@@ -484,14 +493,14 @@ ucl_elt_write_config (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @return rcl output (should be freed after using)
  */
 static void
-ucl_object_emit_config (ucl_object_t *obj, struct ucl_emitter_functions *func)
+ucl_object_emit_config (const ucl_object_t *obj, struct ucl_emitter_functions *func)
 {
 	ucl_elt_write_config (obj, func, 0, false, true, true);
 }
 
 
 static void
-ucl_obj_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_obj_write_yaml (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs)
 {
 	bool is_array = (obj->next != NULL);
@@ -510,10 +519,10 @@ ucl_obj_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf target buffer
  */
 static void
-ucl_elt_obj_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_obj_write_yaml (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top)
 {
-	ucl_object_t *cur;
+	const ucl_object_t *cur;
 	ucl_hash_iter_t it = NULL;
 
 	if (start_tabs) {
@@ -558,10 +567,10 @@ ucl_elt_obj_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf target buffer
  */
 static void
-ucl_elt_array_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_array_write_yaml (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top)
 {
-	ucl_object_t *cur = obj;
+	const ucl_object_t *cur = obj;
 
 	if (start_tabs) {
 		ucl_add_tabs (func, tabs, false);
@@ -583,7 +592,7 @@ ucl_elt_array_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @param buf buffer
  */
 static void
-ucl_elt_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
+ucl_elt_write_yaml (const ucl_object_t *obj, struct ucl_emitter_functions *func,
 		unsigned int tabs, bool start_tabs, bool is_top, bool expand_array)
 {
 	bool flag;
@@ -648,7 +657,7 @@ ucl_elt_write_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func,
  * @return rcl output (should be freed after using)
  */
 static void
-ucl_object_emit_yaml (ucl_object_t *obj, struct ucl_emitter_functions *func)
+ucl_object_emit_yaml (const ucl_object_t *obj, struct ucl_emitter_functions *func)
 {
 	ucl_elt_write_yaml (obj, func, 0, false, true, true);
 }
@@ -715,7 +724,7 @@ ucl_utstring_append_double (double val, void *ud)
 
 
 unsigned char *
-ucl_object_emit (ucl_object_t *obj, enum ucl_emitter emit_type)
+ucl_object_emit (const ucl_object_t *obj, enum ucl_emitter emit_type)
 {
 	UT_string *buf = NULL;
 	unsigned char *res = NULL;
@@ -755,7 +764,7 @@ ucl_object_emit (ucl_object_t *obj, enum ucl_emitter emit_type)
 }
 
 bool
-ucl_object_emit_full (ucl_object_t *obj, enum ucl_emitter emit_type,
+ucl_object_emit_full (const ucl_object_t *obj, enum ucl_emitter emit_type,
 		struct ucl_emitter_functions *emitter)
 {
 	if (emit_type == UCL_EMIT_JSON) {
@@ -777,7 +786,7 @@ ucl_object_emit_full (ucl_object_t *obj, enum ucl_emitter emit_type,
 
 
 unsigned char *
-ucl_object_emit_single_json (ucl_object_t *obj)
+ucl_object_emit_single_json (const ucl_object_t *obj)
 {
 	UT_string *buf = NULL;
 	unsigned char *res = NULL;
diff --git a/contrib/libucl/src/ucl_hash.c b/contrib/libucl/src/ucl_hash.c
index a3711de..c2e80cb 100644
--- a/contrib/libucl/src/ucl_hash.c
+++ b/contrib/libucl/src/ucl_hash.c
@@ -21,6 +21,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "ucl_internal.h"
 #include "ucl_hash.h"
 #include "utlist.h"
 
@@ -39,11 +40,15 @@ ucl_hash_create (void)
 void ucl_hash_destroy (ucl_hash_t* hashlin, ucl_hash_free_func *func)
 {
 	ucl_hash_node_t *elt, *tmp;
+	const ucl_object_t *cur, *otmp;
 
 	HASH_ITER (hh, hashlin->buckets, elt, tmp) {
 		HASH_DELETE (hh, hashlin->buckets, elt);
 		if (func) {
-			func (elt->data);
+			DL_FOREACH_SAFE (elt->data, cur, otmp) {
+				/* Need to deconst here */
+				func (__DECONST (ucl_object_t *, cur));
+			}
 		}
 		UCL_FREE (sizeof (ucl_hash_node_t), elt);
 	}
@@ -51,7 +56,8 @@ void ucl_hash_destroy (ucl_hash_t* hashlin, ucl_hash_free_func *func)
 }
 
 void
-ucl_hash_insert (ucl_hash_t* hashlin, ucl_object_t *obj, const char *key, unsigned keylen)
+ucl_hash_insert (ucl_hash_t* hashlin, const ucl_object_t *obj,
+		const char *key, unsigned keylen)
 {
 	ucl_hash_node_t *node;
 
@@ -60,7 +66,7 @@ ucl_hash_insert (ucl_hash_t* hashlin, ucl_object_t *obj, const char *key, unsign
 	HASH_ADD_KEYPTR (hh, hashlin->buckets, key, keylen, node);
 }
 
-void*
+const void*
 ucl_hash_iterate (ucl_hash_t *hashlin, ucl_hash_iter_t *iter)
 {
 	ucl_hash_node_t *elt = *iter;
@@ -91,7 +97,7 @@ ucl_hash_iter_has_next (ucl_hash_iter_t iter)
 }
 
 
-ucl_object_t*
+const ucl_object_t*
 ucl_hash_search (ucl_hash_t* hashlin, const char *key, unsigned keylen)
 {
 	ucl_hash_node_t *found;
@@ -108,7 +114,7 @@ ucl_hash_search (ucl_hash_t* hashlin, const char *key, unsigned keylen)
 }
 
 void
-ucl_hash_delete (ucl_hash_t* hashlin, ucl_object_t *obj)
+ucl_hash_delete (ucl_hash_t* hashlin, const ucl_object_t *obj)
 {
 	ucl_hash_node_t *found;
 
diff --git a/contrib/libucl/src/ucl_hash.h b/contrib/libucl/src/ucl_hash.h
index 5c9b851..cbbf005 100644
--- a/contrib/libucl/src/ucl_hash.h
+++ b/contrib/libucl/src/ucl_hash.h
@@ -31,7 +31,7 @@
 
 typedef struct ucl_hash_node_s
 {
-	ucl_object_t *data;
+	const ucl_object_t *data;
 	UT_hash_handle hh;
 } ucl_hash_node_t;
 
@@ -62,17 +62,19 @@ void ucl_hash_destroy (ucl_hash_t* hashlin, ucl_hash_free_func *func);
 /**
  * Inserts an element in the the hashtable.
  */
-void ucl_hash_insert (ucl_hash_t* hashlin, ucl_object_t *obj, const char *key, unsigned keylen);
+void ucl_hash_insert (ucl_hash_t* hashlin, const ucl_object_t *obj, const char *key,
+		unsigned keylen);
 
 /**
  * Delete an element from the the hashtable.
  */
-void ucl_hash_delete (ucl_hash_t* hashlin, ucl_object_t *obj);
+void ucl_hash_delete (ucl_hash_t* hashlin, const ucl_object_t *obj);
 
 /**
  * Searches an element in the hashtable.
  */
-ucl_object_t* ucl_hash_search (ucl_hash_t* hashlin, const char *key, unsigned keylen);
+const ucl_object_t* ucl_hash_search (ucl_hash_t* hashlin, const char *key,
+		unsigned keylen);
 
 
 /**
@@ -81,7 +83,7 @@ ucl_object_t* ucl_hash_search (ucl_hash_t* hashlin, const char *key, unsigned ke
  * @param iter iterator (must be NULL on first iteration)
  * @return the next object
  */
-void* ucl_hash_iterate (ucl_hash_t *hashlin, ucl_hash_iter_t *iter);
+const void* ucl_hash_iterate (ucl_hash_t *hashlin, ucl_hash_iter_t *iter);
 
 /**
  * Check whether an iterator has next element
diff --git a/contrib/libucl/src/ucl_internal.h b/contrib/libucl/src/ucl_internal.h
index 49c4aae..0e3ecd0 100644
--- a/contrib/libucl/src/ucl_internal.h
+++ b/contrib/libucl/src/ucl_internal.h
@@ -24,18 +24,69 @@
 #ifndef UCL_INTERNAL_H_
 #define UCL_INTERNAL_H_
 
-#include <sys/types.h>
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#else
+/* Help embedded builds */
+#define HAVE_SYS_TYPES_H
+#define HAVE_SYS_MMAN_H
+#define HAVE_SYS_STAT_H
+#define HAVE_SYS_PARAM_H
+#define HAVE_LIMITS_H
+#define HAVE_FCNTL_H
+#define HAVE_ERRNO_H
+#define HAVE_UNISTD_H
+#define HAVE_CTYPE_H
+#define HAVE_STDIO_H
+#define HAVE_STRING_H
+#define HAVE_FLOAT_H
+#define HAVE_LIBGEN_H
+#define HAVE_MATH_H
+#define HAVE_STDBOOL_H
+#define HAVE_STDINT_H
+#define HAVE_STDARG_H
 #ifndef _WIN32
-#include <sys/mman.h>
+# define HAVE_REGEX_H
+#endif
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+# ifndef _WIN32
+#  include <sys/mman.h>
+# endif
 #endif
+#ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
+#endif
+#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
+#endif
 
+#ifdef HAVE_LIMITS_H
 #include <limits.h>
+#endif
+#ifdef HAVE_FCNTL_H
 #include <fcntl.h>
+#endif
+#ifdef HAVE_ERRNO_H
 #include <errno.h>
+#endif
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_CTYPE_H
 #include <ctype.h>
+#endif
+#ifdef HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
 
 #include "utlist.h"
 #include "utstring.h"
@@ -48,6 +99,10 @@
 #include <openssl/evp.h>
 #endif
 
+#ifndef __DECONST
+#define __DECONST(type, var)    ((type)(uintptr_t)(const void *)(var))
+#endif
+
 /**
  * @file rcl_internal.h
  * Internal structures and functions of UCL library
@@ -142,6 +197,8 @@ struct ucl_parser {
 	struct ucl_chunk *chunks;
 	struct ucl_pubkey *keys;
 	struct ucl_variable *variables;
+	ucl_variable_handler var_handler;
+	void *var_data;
 	UT_string *err;
 };
 
@@ -261,20 +318,21 @@ ucl_maybe_parse_boolean (ucl_object_t *obj, const unsigned char *start, size_t l
  * @return 0 if string is numeric and error code (EINVAL or ERANGE) in case of conversion error
  */
 int ucl_maybe_parse_number (ucl_object_t *obj,
-		const char *start, const char *end, const char **pos, bool allow_double, bool number_bytes);
+		const char *start, const char *end, const char **pos,
+		bool allow_double, bool number_bytes, bool allow_time);
 
 
-static inline ucl_object_t *
+static inline const ucl_object_t *
 ucl_hash_search_obj (ucl_hash_t* hashlin, ucl_object_t *obj)
 {
-	return (ucl_object_t *)ucl_hash_search (hashlin, obj->key, obj->keylen);
+	return (const ucl_object_t *)ucl_hash_search (hashlin, obj->key, obj->keylen);
 }
 
 static inline ucl_hash_t *
-ucl_hash_insert_object (ucl_hash_t *hashlin, ucl_object_t *obj) UCL_WARN_UNUSED_RESULT;
+ucl_hash_insert_object (ucl_hash_t *hashlin, const ucl_object_t *obj) UCL_WARN_UNUSED_RESULT;
 
 static inline ucl_hash_t *
-ucl_hash_insert_object (ucl_hash_t *hashlin, ucl_object_t *obj)
+ucl_hash_insert_object (ucl_hash_t *hashlin, const ucl_object_t *obj)
 {
 	if (hashlin == NULL) {
 		hashlin = ucl_hash_create ();
@@ -289,6 +347,6 @@ ucl_hash_insert_object (ucl_hash_t *hashlin, ucl_object_t *obj)
  * @param obj
  * @return
  */
-unsigned char * ucl_object_emit_single_json (ucl_object_t *obj);
+unsigned char * ucl_object_emit_single_json (const ucl_object_t *obj);
 
 #endif /* UCL_INTERNAL_H_ */
diff --git a/contrib/libucl/src/ucl_parser.c b/contrib/libucl/src/ucl_parser.c
index 12ebad2..b4fe5af 100644
--- a/contrib/libucl/src/ucl_parser.c
+++ b/contrib/libucl/src/ucl_parser.c
@@ -55,34 +55,6 @@ struct ucl_parser_saved_state {
     (chunk)->remain --;										\
     } while (0)
 
-/**
- * Save parser state
- * @param chunk
- * @param s
- */
-static inline void
-ucl_chunk_save_state (struct ucl_chunk *chunk, struct ucl_parser_saved_state *s)
-{
-	s->column = chunk->column;
-	s->pos = chunk->pos;
-	s->line = chunk->line;
-	s->remain = chunk->remain;
-}
-
-/**
- * Restore parser state
- * @param chunk
- * @param s
- */
-static inline void
-ucl_chunk_restore_state (struct ucl_chunk *chunk, struct ucl_parser_saved_state *s)
-{
-	chunk->column = s->column;
-	chunk->pos = s->pos;
-	chunk->line = s->line;
-	chunk->remain = s->remain;
-}
-
 static inline void
 ucl_set_err (struct ucl_chunk *chunk, int code, const char *str, UT_string **err)
 {
@@ -264,6 +236,9 @@ ucl_check_variable_safe (struct ucl_parser *parser, const char *ptr, size_t rema
 		size_t *out_len, bool strict, bool *found)
 {
 	struct ucl_variable *var;
+	unsigned char *dst;
+	size_t dstlen;
+	bool need_free = false;
 
 	LL_FOREACH (parser->variables, var) {
 		if (strict) {
@@ -286,6 +261,19 @@ ucl_check_variable_safe (struct ucl_parser *parser, const char *ptr, size_t rema
 		}
 	}
 
+	/* XXX: can only handle ${VAR} */
+	if (!(*found) && parser->var_handler != NULL && strict) {
+		/* Call generic handler */
+		if (parser->var_handler (ptr, remain, &dst, &dstlen, &need_free,
+				parser->var_data)) {
+			*found = true;
+			if (need_free) {
+				free (dst);
+			}
+			return (ptr + remain);
+		}
+	}
+
 	return ptr;
 }
 
@@ -299,7 +287,8 @@ ucl_check_variable_safe (struct ucl_parser *parser, const char *ptr, size_t rema
  * @return
  */
 static const char *
-ucl_check_variable (struct ucl_parser *parser, const char *ptr, size_t remain, size_t *out_len, bool *vars_found)
+ucl_check_variable (struct ucl_parser *parser, const char *ptr,
+		size_t remain, size_t *out_len, bool *vars_found)
 {
 	const char *p, *end, *ret = ptr;
 	bool found = false;
@@ -310,7 +299,8 @@ ucl_check_variable (struct ucl_parser *parser, const char *ptr, size_t remain, s
 		end = ptr + remain;
 		while (p < end) {
 			if (*p == '}') {
-				ret = ucl_check_variable_safe (parser, ptr + 1, p - ptr - 1, out_len, true, &found);
+				ret = ucl_check_variable_safe (parser, ptr + 1, p - ptr - 1,
+						out_len, true, &found);
 				if (found) {
 					/* {} must be excluded actually */
 					ret ++;
@@ -356,10 +346,13 @@ static const char *
 ucl_expand_single_variable (struct ucl_parser *parser, const char *ptr,
 		size_t remain, unsigned char **dest)
 {
-	unsigned char *d = *dest;
+	unsigned char *d = *dest, *dst;
 	const char *p = ptr + 1, *ret;
 	struct ucl_variable *var;
+	size_t dstlen;
+	bool need_free = false;
 	bool found = false;
+	bool strict = false;
 
 	ret = ptr + 1;
 	remain --;
@@ -371,6 +364,7 @@ ucl_expand_single_variable (struct ucl_parser *parser, const char *ptr,
 	}
 	else if (*p == '{') {
 		p ++;
+		strict = true;
 		ret += 2;
 		remain -= 2;
 	}
@@ -387,9 +381,22 @@ ucl_expand_single_variable (struct ucl_parser *parser, const char *ptr,
 		}
 	}
 	if (!found) {
-		memcpy (d, ptr, 2);
-		d += 2;
-		ret --;
+		if (strict && parser->var_handler != NULL) {
+			if (parser->var_handler (ptr, remain, &dst, &dstlen, &need_free,
+							parser->var_data)) {
+				memcpy (d, dst, dstlen);
+				ret += dstlen;
+				d += remain;
+				found = true;
+			}
+		}
+
+		/* Leave variable as is */
+		if (!found) {
+			memcpy (d, ptr, 2);
+			d += 2;
+			ret --;
+		}
 	}
 
 	*dest = d;
@@ -544,6 +551,10 @@ ucl_add_parser_stack (ucl_object_t *obj, struct ucl_parser *parser, bool is_arra
 	}
 
 	st = UCL_ALLOC (sizeof (struct ucl_stack));
+	if (st == NULL) {
+		ucl_set_err (parser->chunks, 0, "cannot allocate memory for an object", &parser->err);
+		return NULL;
+	}
 	st->obj = obj;
 	st->level = level;
 	LL_PREPEND (parser->stack, st);
@@ -554,12 +565,13 @@ ucl_add_parser_stack (ucl_object_t *obj, struct ucl_parser *parser, bool is_arra
 
 int
 ucl_maybe_parse_number (ucl_object_t *obj,
-		const char *start, const char *end, const char **pos, bool allow_double, bool number_bytes)
+		const char *start, const char *end, const char **pos,
+		bool allow_double, bool number_bytes, bool allow_time)
 {
 	const char *p = start, *c = start;
 	char *endptr;
 	bool got_dot = false, got_exp = false, need_double = false,
-			is_date = false, valid_start = false, is_hex = false,
+			is_time = false, valid_start = false, is_hex = false,
 			is_neg = false;
 	double dv = 0;
 	int64_t lv = 0;
@@ -657,7 +669,8 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 	}
 
 	/* Now check endptr */
-	if (endptr == NULL || ucl_lex_is_atom_end (*endptr) || *endptr == '\0') {
+	if (endptr == NULL || ucl_lex_is_atom_end (*endptr) || *endptr == '\0' ||
+			ucl_test_character (*endptr, UCL_CHARACTER_WHITESPACE_UNSAFE)) {
 		p = endptr;
 		goto set_obj;
 	}
@@ -678,7 +691,7 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 						need_double = true;
 						dv = lv;
 					}
-					is_date = true;
+					is_time = true;
 					if (p[0] == 'm' || p[0] == 'M') {
 						dv /= 1000.;
 					}
@@ -708,7 +721,7 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 					p ++;
 					goto set_obj;
 				}
-				else if (end - p >= 3) {
+				else if (allow_time && end - p >= 3) {
 					if (tolower (p[0]) == 'm' &&
 							tolower (p[1]) == 'i' &&
 							tolower (p[2]) == 'n') {
@@ -717,7 +730,7 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 							need_double = true;
 							dv = lv;
 						}
-						is_date = true;
+						is_time = true;
 						dv *= 60.;
 						p += 3;
 						goto set_obj;
@@ -737,13 +750,14 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 			break;
 		case 'S':
 		case 's':
-			if (p == end - 1 || ucl_lex_is_atom_end (p[1])) {
+			if (allow_time &&
+					(p == end - 1 || ucl_lex_is_atom_end (p[1]))) {
 				if (!need_double) {
 					need_double = true;
 					dv = lv;
 				}
 				p ++;
-				is_date = true;
+				is_time = true;
 				goto set_obj;
 			}
 			break;
@@ -755,12 +769,13 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 		case 'W':
 		case 'Y':
 		case 'y':
-			if (p == end - 1 || ucl_lex_is_atom_end (p[1])) {
+			if (allow_time &&
+					(p == end - 1 || ucl_lex_is_atom_end (p[1]))) {
 				if (!need_double) {
 					need_double = true;
 					dv = lv;
 				}
-				is_date = true;
+				is_time = true;
 				dv *= ucl_lex_time_multiplier (*p);
 				p ++;
 				goto set_obj;
@@ -773,8 +788,8 @@ ucl_maybe_parse_number (ucl_object_t *obj,
 	return EINVAL;
 
 	set_obj:
-	if (allow_double && (need_double || is_date)) {
-		if (!is_date) {
+	if (allow_double && (need_double || is_time)) {
+		if (!is_time) {
 			obj->type = UCL_FLOAT;
 		}
 		else {
@@ -803,7 +818,8 @@ ucl_lex_number (struct ucl_parser *parser,
 	const unsigned char *pos;
 	int ret;
 
-	ret = ucl_maybe_parse_number (obj, chunk->pos, chunk->end, (const char **)&pos, true, false);
+	ret = ucl_maybe_parse_number (obj, chunk->pos, chunk->end, (const char **)&pos,
+			true, false, ((parser->flags & UCL_PARSER_NO_TIME) == 0));
 
 	if (ret == 0) {
 		chunk->remain -= pos - chunk->pos;
@@ -1077,19 +1093,19 @@ ucl_parse_key (struct ucl_parser *parser, struct ucl_chunk *chunk, bool *next_ke
 	keylen = ucl_copy_or_store_ptr (parser, c, &nobj->trash_stack[UCL_TRASH_KEY],
 			&key, end - c, need_unescape, parser->flags & UCL_PARSER_KEY_LOWERCASE, false);
 	if (keylen == -1) {
-		ucl_object_free(nobj);
+		ucl_object_unref (nobj);
 		return false;
 	}
 	else if (keylen == 0) {
 		ucl_set_err (chunk, UCL_ESYNTAX, "empty keys are not allowed", &parser->err);
-		ucl_object_free(nobj);
+		ucl_object_unref (nobj);
 		return false;
 	}
 
 	container = parser->stack->obj->value.ov;
 	nobj->key = key;
 	nobj->keylen = keylen;
-	tobj = ucl_hash_search_obj (container, nobj);
+	tobj = __DECONST (ucl_object_t *, ucl_hash_search_obj (container, nobj));
 	if (tobj == NULL) {
 		container = ucl_hash_insert_object (container, nobj);
 		nobj->prev = nobj;
@@ -1308,6 +1324,9 @@ ucl_parse_value (struct ucl_parser *parser, struct ucl_chunk *chunk)
 			obj = ucl_get_value_object (parser);
 			/* We have a new object */
 			obj = ucl_add_parser_stack (obj, parser, false, parser->stack->level);
+			if (obj == NULL) {
+				return false;
+			}
 
 			ucl_chunk_skipc (chunk, p);
 			return true;
@@ -1316,6 +1335,9 @@ ucl_parse_value (struct ucl_parser *parser, struct ucl_chunk *chunk)
 			obj = ucl_get_value_object (parser);
 			/* We have a new array */
 			obj = ucl_add_parser_stack (obj, parser, true, parser->stack->level);
+			if (obj == NULL) {
+				return false;
+			}
 
 			ucl_chunk_skipc (chunk, p);
 			return true;
@@ -1608,6 +1630,9 @@ ucl_state_machine (struct ucl_parser *parser)
 		else {
 			obj = ucl_add_parser_stack (NULL, parser, false, 0);
 		}
+		if (obj == NULL) {
+			return false;
+		}
 		parser->top_obj = obj;
 		parser->cur_obj = obj;
 		parser->state = UCL_STATE_INIT;
@@ -1673,7 +1698,11 @@ ucl_state_machine (struct ucl_parser *parser)
 			else if (parser->state != UCL_STATE_MACRO_NAME) {
 				if (next_key && parser->stack->obj->type == UCL_OBJECT) {
 					/* Parse more keys and nest objects accordingly */
-					obj = ucl_add_parser_stack (parser->cur_obj, parser, false, parser->stack->level + 1);
+					obj = ucl_add_parser_stack (parser->cur_obj, parser, false,
+							parser->stack->level + 1);
+					if (obj == NULL) {
+						return false;
+					}
 				}
 				else {
 					parser->state = UCL_STATE_VALUE;
@@ -1787,6 +1816,9 @@ ucl_parser_new (int flags)
 	struct ucl_parser *new;
 
 	new = UCL_ALLOC (sizeof (struct ucl_parser));
+	if (new == NULL) {
+		return NULL;
+	}
 	memset (new, 0, sizeof (struct ucl_parser));
 
 	ucl_parser_register_macro (new, "include", ucl_include_handler, new);
@@ -1808,7 +1840,13 @@ ucl_parser_register_macro (struct ucl_parser *parser, const char *macro,
 {
 	struct ucl_macro *new;
 
+	if (macro == NULL || handler == NULL) {
+		return;
+	}
 	new = UCL_ALLOC (sizeof (struct ucl_macro));
+	if (new == NULL) {
+		return;
+	}
 	memset (new, 0, sizeof (struct ucl_macro));
 	new->handler = handler;
 	new->name = strdup (macro);
@@ -1851,6 +1889,9 @@ ucl_parser_register_variable (struct ucl_parser *parser, const char *var,
 	else {
 		if (new == NULL) {
 			new = UCL_ALLOC (sizeof (struct ucl_variable));
+			if (new == NULL) {
+				return;
+			}
 			memset (new, 0, sizeof (struct ucl_variable));
 			new->var = strdup (var);
 			new->var_len = strlen (var);
@@ -1867,14 +1908,30 @@ ucl_parser_register_variable (struct ucl_parser *parser, const char *var,
 	}
 }
 
+void
+ucl_parser_set_variables_handler (struct ucl_parser *parser,
+		ucl_variable_handler handler, void *ud)
+{
+	parser->var_handler = handler;
+	parser->var_data = ud;
+}
+
 bool
 ucl_parser_add_chunk (struct ucl_parser *parser, const unsigned char *data,
 		size_t len)
 {
 	struct ucl_chunk *chunk;
 
+	if (data == NULL || len == 0) {
+		ucl_create_err (&parser->err, "invalid chunk added");
+		return false;
+	}
 	if (parser->state != UCL_STATE_ERROR) {
 		chunk = UCL_ALLOC (sizeof (struct ucl_chunk));
+		if (chunk == NULL) {
+			ucl_create_err (&parser->err, "cannot allocate chunk structure");
+			return false;
+		}
 		chunk->begin = data;
 		chunk->remain = len;
 		chunk->pos = chunk->begin;
@@ -1895,3 +1952,18 @@ ucl_parser_add_chunk (struct ucl_parser *parser, const unsigned char *data,
 
 	return false;
 }
+
+bool
+ucl_parser_add_string (struct ucl_parser *parser, const char *data,
+		size_t len)
+{
+	if (data == NULL) {
+		ucl_create_err (&parser->err, "invalid string added");
+		return false;
+	}
+	if (len == 0) {
+		len = strlen (data);
+	}
+
+	return ucl_parser_add_chunk (parser, (const unsigned char *)data, len);
+}
diff --git a/contrib/libucl/src/ucl_schema.c b/contrib/libucl/src/ucl_schema.c
new file mode 100644
index 0000000..faffe86
--- /dev/null
+++ b/contrib/libucl/src/ucl_schema.c
@@ -0,0 +1,1014 @@
+/*
+ * Copyright (c) 2014, Vsevolod Stakhov
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *	 * Redistributions of source code must retain the above copyright
+ *	   notice, this list of conditions and the following disclaimer.
+ *	 * Redistributions in binary form must reproduce the above copyright
+ *	   notice, this list of conditions and the following disclaimer in the
+ *	   documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "ucl.h"
+#include "ucl_internal.h"
+#include "tree.h"
+#include "utlist.h"
+#ifdef HAVE_STDARG_H
+#include <stdarg.h>
+#endif
+#ifdef HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#ifdef HAVE_REGEX_H
+#include <regex.h>
+#endif
+#ifdef HAVE_MATH_H
+#include <math.h>
+#endif
+
+static bool ucl_schema_validate (const ucl_object_t *schema,
+		const ucl_object_t *obj, bool try_array,
+		struct ucl_schema_error *err,
+		const ucl_object_t *root);
+
+static bool
+ucl_string_to_type (const char *input, ucl_type_t *res)
+{
+	if (strcasecmp (input, "object") == 0) {
+		*res = UCL_OBJECT;
+	}
+	else if (strcasecmp (input, "array") == 0) {
+		*res = UCL_ARRAY;
+	}
+	else if (strcasecmp (input, "integer") == 0) {
+		*res = UCL_INT;
+	}
+	else if (strcasecmp (input, "number") == 0) {
+		*res = UCL_FLOAT;
+	}
+	else if (strcasecmp (input, "string") == 0) {
+		*res = UCL_STRING;
+	}
+	else if (strcasecmp (input, "boolean") == 0) {
+		*res = UCL_BOOLEAN;
+	}
+	else if (strcasecmp (input, "null") == 0) {
+		*res = UCL_NULL;
+	}
+	else {
+		return false;
+	}
+
+	return true;
+}
+
+static const char *
+ucl_object_type_to_string (ucl_type_t type)
+{
+	const char *res = "unknown";
+
+	switch (type) {
+	case UCL_OBJECT:
+		res = "object";
+		break;
+	case UCL_ARRAY:
+		res = "array";
+		break;
+	case UCL_INT:
+		res = "integer";
+		break;
+	case UCL_FLOAT:
+	case UCL_TIME:
+		res = "number";
+		break;
+	case UCL_STRING:
+		res = "string";
+		break;
+	case UCL_BOOLEAN:
+		res = "boolean";
+		break;
+	case UCL_NULL:
+	case UCL_USERDATA:
+		res = "null";
+		break;
+	}
+
+	return res;
+}
+
+/*
+ * Create validation error
+ */
+static void
+ucl_schema_create_error (struct ucl_schema_error *err,
+		enum ucl_schema_error_code code, const ucl_object_t *obj,
+		const char *fmt, ...)
+{
+	va_list va;
+
+	if (err != NULL) {
+		err->code = code;
+		err->obj = obj;
+		va_start (va, fmt);
+		vsnprintf (err->msg, sizeof (err->msg), fmt, va);
+		va_end (va);
+	}
+}
+
+/*
+ * Check whether we have a pattern specified
+ */
+static const ucl_object_t *
+ucl_schema_test_pattern (const ucl_object_t *obj, const char *pattern)
+{
+	const ucl_object_t *res = NULL;
+#ifdef HAVE_REGEX_H
+	regex_t reg;
+	const ucl_object_t *elt;
+	ucl_object_iter_t iter = NULL;
+
+	if (regcomp (&reg, pattern, REG_EXTENDED | REG_NOSUB) == 0) {
+		while ((elt = ucl_iterate_object (obj, &iter, true)) != NULL) {
+			if (regexec (&reg, ucl_object_key (elt), 0, NULL, 0) == 0) {
+				res = elt;
+				break;
+			}
+		}
+		regfree (&reg);
+	}
+#endif
+	return res;
+}
+
+/*
+ * Check dependencies for an object
+ */
+static bool
+ucl_schema_validate_dependencies (const ucl_object_t *deps,
+		const ucl_object_t *obj, struct ucl_schema_error *err,
+		const ucl_object_t *root)
+{
+	const ucl_object_t *elt, *cur, *cur_dep;
+	ucl_object_iter_t iter = NULL, piter;
+	bool ret = true;
+
+	while (ret && (cur = ucl_iterate_object (deps, &iter, true)) != NULL) {
+		elt = ucl_object_find_key (obj, ucl_object_key (cur));
+		if (elt != NULL) {
+			/* Need to check dependencies */
+			if (cur->type == UCL_ARRAY) {
+				piter = NULL;
+				while (ret && (cur_dep = ucl_iterate_object (cur, &piter, true)) != NULL) {
+					if (ucl_object_find_key (obj, ucl_object_tostring (cur_dep)) == NULL) {
+						ucl_schema_create_error (err, UCL_SCHEMA_MISSING_DEPENDENCY, elt,
+								"dependency %s is missing for key %s",
+								ucl_object_tostring (cur_dep), ucl_object_key (cur));
+						ret = false;
+						break;
+					}
+				}
+			}
+			else if (cur->type == UCL_OBJECT) {
+				ret = ucl_schema_validate (cur, obj, true, err, root);
+			}
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Validate object
+ */
+static bool
+ucl_schema_validate_object (const ucl_object_t *schema,
+		const ucl_object_t *obj, struct ucl_schema_error *err,
+		const ucl_object_t *root)
+{
+	const ucl_object_t *elt, *prop, *found, *additional_schema = NULL,
+			*required = NULL, *pat, *pelt;
+	ucl_object_iter_t iter = NULL, piter = NULL;
+	bool ret = true, allow_additional = true;
+	int64_t minmax;
+
+	while (ret && (elt = ucl_iterate_object (schema, &iter, true)) != NULL) {
+		if (elt->type == UCL_OBJECT &&
+				strcmp (ucl_object_key (elt), "properties") == 0) {
+			piter = NULL;
+			while (ret && (prop = ucl_iterate_object (elt, &piter, true)) != NULL) {
+				found = ucl_object_find_key (obj, ucl_object_key (prop));
+				if (found) {
+					ret = ucl_schema_validate (prop, found, true, err, root);
+				}
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "additionalProperties") == 0) {
+			if (elt->type == UCL_BOOLEAN) {
+				if (!ucl_object_toboolean (elt)) {
+					/* Deny additional fields completely */
+					allow_additional = false;
+				}
+			}
+			else if (elt->type == UCL_OBJECT) {
+				/* Define validator for additional fields */
+				additional_schema = elt;
+			}
+			else {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"additionalProperties attribute is invalid in schema");
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "required") == 0) {
+			if (elt->type == UCL_ARRAY) {
+				required = elt;
+			}
+			else {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"required attribute is invalid in schema");
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "minProperties") == 0
+				&& ucl_object_toint_safe (elt, &minmax)) {
+			if (obj->len < minmax) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"object has not enough properties: %u, minimum is: %u",
+						obj->len, (unsigned)minmax);
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "maxProperties") == 0
+				&& ucl_object_toint_safe (elt, &minmax)) {
+			if (obj->len > minmax) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"object has too many properties: %u, maximum is: %u",
+						obj->len, (unsigned)minmax);
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "patternProperties") == 0) {
+			piter = NULL;
+			while (ret && (prop = ucl_iterate_object (elt, &piter, true)) != NULL) {
+				found = ucl_schema_test_pattern (obj, ucl_object_key (prop));
+				if (found) {
+					ret = ucl_schema_validate (prop, found, true, err, root);
+				}
+			}
+		}
+		else if (elt->type == UCL_OBJECT &&
+				strcmp (ucl_object_key (elt), "dependencies") == 0) {
+			ret = ucl_schema_validate_dependencies (elt, obj, err, root);
+		}
+	}
+
+	if (ret) {
+		/* Additional properties */
+		if (!allow_additional || additional_schema != NULL) {
+			/* Check if we have exactly the same properties in schema and object */
+			iter = NULL;
+			prop = ucl_object_find_key (schema, "properties");
+			while ((elt = ucl_iterate_object (obj, &iter, true)) != NULL) {
+				found = ucl_object_find_key (prop, ucl_object_key (elt));
+				if (found == NULL) {
+					/* Try patternProperties */
+					piter = NULL;
+					pat = ucl_object_find_key (schema, "patternProperties");
+					while ((pelt = ucl_iterate_object (pat, &piter, true)) != NULL) {
+						found = ucl_schema_test_pattern (obj, ucl_object_key (pelt));
+						if (found != NULL) {
+							break;
+						}
+					}
+				}
+				if (found == NULL) {
+					if (!allow_additional) {
+						ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+								"object has non-allowed property %s",
+								ucl_object_key (elt));
+						ret = false;
+						break;
+					}
+					else if (additional_schema != NULL) {
+						if (!ucl_schema_validate (additional_schema, elt, true, err, root)) {
+							ret = false;
+							break;
+						}
+					}
+				}
+			}
+		}
+		/* Required properties */
+		if (required != NULL) {
+			iter = NULL;
+			while ((elt = ucl_iterate_object (required, &iter, true)) != NULL) {
+				if (ucl_object_find_key (obj, ucl_object_tostring (elt)) == NULL) {
+					ucl_schema_create_error (err, UCL_SCHEMA_MISSING_PROPERTY, obj,
+							"object has missing property %s",
+							ucl_object_tostring (elt));
+					ret = false;
+					break;
+				}
+			}
+		}
+	}
+
+
+	return ret;
+}
+
+static bool
+ucl_schema_validate_number (const ucl_object_t *schema,
+		const ucl_object_t *obj, struct ucl_schema_error *err)
+{
+	const ucl_object_t *elt, *test;
+	ucl_object_iter_t iter = NULL;
+	bool ret = true, exclusive = false;
+	double constraint, val;
+	const double alpha = 1e-16;
+
+	while (ret && (elt = ucl_iterate_object (schema, &iter, true)) != NULL) {
+		if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
+				strcmp (ucl_object_key (elt), "multipleOf") == 0) {
+			constraint = ucl_object_todouble (elt);
+			if (constraint <= 0) {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"multipleOf must be greater than zero");
+				ret = false;
+				break;
+			}
+			val = ucl_object_todouble (obj);
+			if (fabs (remainder (val, constraint)) > alpha) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"number %.4f is not multiple of %.4f, remainder is %.7f",
+						val, constraint);
+				ret = false;
+				break;
+			}
+		}
+		else if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
+			strcmp (ucl_object_key (elt), "maximum") == 0) {
+			constraint = ucl_object_todouble (elt);
+			test = ucl_object_find_key (schema, "exclusiveMaximum");
+			if (test && test->type == UCL_BOOLEAN) {
+				exclusive = ucl_object_toboolean (test);
+			}
+			val = ucl_object_todouble (obj);
+			if (val > constraint || (exclusive && val >= constraint)) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"number is too big: %.3f, maximum is: %.3f",
+						val, constraint);
+				ret = false;
+				break;
+			}
+		}
+		else if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
+				strcmp (ucl_object_key (elt), "minimum") == 0) {
+			constraint = ucl_object_todouble (elt);
+			test = ucl_object_find_key (schema, "exclusiveMinimum");
+			if (test && test->type == UCL_BOOLEAN) {
+				exclusive = ucl_object_toboolean (test);
+			}
+			val = ucl_object_todouble (obj);
+			if (val < constraint || (exclusive && val <= constraint)) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"number is too small: %.3f, minimum is: %.3f",
+						val, constraint);
+				ret = false;
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static bool
+ucl_schema_validate_string (const ucl_object_t *schema,
+		const ucl_object_t *obj, struct ucl_schema_error *err)
+{
+	const ucl_object_t *elt;
+	ucl_object_iter_t iter = NULL;
+	bool ret = true;
+	int64_t constraint;
+#ifdef HAVE_REGEX_H
+	regex_t re;
+#endif
+
+	while (ret && (elt = ucl_iterate_object (schema, &iter, true)) != NULL) {
+		if (elt->type == UCL_INT &&
+			strcmp (ucl_object_key (elt), "maxLength") == 0) {
+			constraint = ucl_object_toint (elt);
+			if (obj->len > constraint) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"string is too big: %.3f, maximum is: %.3f",
+						obj->len, constraint);
+				ret = false;
+				break;
+			}
+		}
+		else if (elt->type == UCL_INT &&
+				strcmp (ucl_object_key (elt), "minLength") == 0) {
+			constraint = ucl_object_toint (elt);
+			if (obj->len < constraint) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"string is too short: %.3f, minimum is: %.3f",
+						obj->len, constraint);
+				ret = false;
+				break;
+			}
+		}
+#ifdef HAVE_REGEX_H
+		else if (elt->type == UCL_STRING &&
+				strcmp (ucl_object_key (elt), "pattern") == 0) {
+			if (regcomp (&re, ucl_object_tostring (elt),
+					REG_EXTENDED | REG_NOSUB) != 0) {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"cannot compile pattern %s", ucl_object_tostring (elt));
+				ret = false;
+				break;
+			}
+			if (regexec (&re, ucl_object_tostring (obj), 0, NULL, 0) != 0) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"string doesn't match regexp %s",
+						ucl_object_tostring (elt));
+				ret = false;
+			}
+			regfree (&re);
+		}
+#endif
+	}
+
+	return ret;
+}
+
+struct ucl_compare_node {
+	const ucl_object_t *obj;
+	TREE_ENTRY(ucl_compare_node) link;
+	struct ucl_compare_node *next;
+};
+
+typedef TREE_HEAD(_tree, ucl_compare_node) ucl_compare_tree_t;
+
+TREE_DEFINE(ucl_compare_node, link)
+
+static int
+ucl_schema_elt_compare (struct ucl_compare_node *n1, struct ucl_compare_node *n2)
+{
+	const ucl_object_t *o1 = n1->obj, *o2 = n2->obj;
+
+	return ucl_object_compare (o1, o2);
+}
+
+static bool
+ucl_schema_array_is_unique (const ucl_object_t *obj, struct ucl_schema_error *err)
+{
+	ucl_compare_tree_t tree = TREE_INITIALIZER (ucl_schema_elt_compare);
+	ucl_object_iter_t iter = NULL;
+	const ucl_object_t *elt;
+	struct ucl_compare_node *node, test, *nodes = NULL, *tmp;
+	bool ret = true;
+
+	while ((elt = ucl_iterate_object (obj, &iter, true)) != NULL) {
+		test.obj = elt;
+		node = TREE_FIND (&tree, ucl_compare_node, link, &test);
+		if (node != NULL) {
+			ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, elt,
+					"duplicate values detected while uniqueItems is true");
+			ret = false;
+			break;
+		}
+		node = calloc (1, sizeof (*node));
+		if (node == NULL) {
+			ucl_schema_create_error (err, UCL_SCHEMA_UNKNOWN, elt,
+					"cannot allocate tree node");
+			ret = false;
+			break;
+		}
+		node->obj = elt;
+		TREE_INSERT (&tree, ucl_compare_node, link, node);
+		LL_PREPEND (nodes, node);
+	}
+
+	LL_FOREACH_SAFE (nodes, node, tmp) {
+		free (node);
+	}
+
+	return ret;
+}
+
+static bool
+ucl_schema_validate_array (const ucl_object_t *schema,
+		const ucl_object_t *obj, struct ucl_schema_error *err,
+		const ucl_object_t *root)
+{
+	const ucl_object_t *elt, *it, *found, *additional_schema = NULL,
+			*first_unvalidated = NULL;
+	ucl_object_iter_t iter = NULL, piter = NULL;
+	bool ret = true, allow_additional = true, need_unique = false;
+	int64_t minmax;
+
+	while (ret && (elt = ucl_iterate_object (schema, &iter, true)) != NULL) {
+		if (strcmp (ucl_object_key (elt), "items") == 0) {
+			if (elt->type == UCL_ARRAY) {
+				found = obj->value.av;
+				while (ret && (it = ucl_iterate_object (elt, &piter, true)) != NULL) {
+					if (found) {
+						ret = ucl_schema_validate (it, found, false, err, root);
+						found = found->next;
+					}
+				}
+				if (found != NULL) {
+					/* The first element that is not validated */
+					first_unvalidated = found;
+				}
+			}
+			else if (elt->type == UCL_OBJECT) {
+				/* Validate all items using the specified schema */
+				while (ret && (it = ucl_iterate_object (obj, &piter, true)) != NULL) {
+					ret = ucl_schema_validate (elt, it, false, err, root);
+				}
+			}
+			else {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"items attribute is invalid in schema");
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "additionalItems") == 0) {
+			if (elt->type == UCL_BOOLEAN) {
+				if (!ucl_object_toboolean (elt)) {
+					/* Deny additional fields completely */
+					allow_additional = false;
+				}
+			}
+			else if (elt->type == UCL_OBJECT) {
+				/* Define validator for additional fields */
+				additional_schema = elt;
+			}
+			else {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
+						"additionalItems attribute is invalid in schema");
+				ret = false;
+				break;
+			}
+		}
+		else if (elt->type == UCL_BOOLEAN &&
+				strcmp (ucl_object_key (elt), "uniqueItems") == 0) {
+			need_unique = ucl_object_toboolean (elt);
+		}
+		else if (strcmp (ucl_object_key (elt), "minItems") == 0
+				&& ucl_object_toint_safe (elt, &minmax)) {
+			if (obj->len < minmax) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"array has not enough items: %u, minimum is: %u",
+						obj->len, (unsigned)minmax);
+				ret = false;
+				break;
+			}
+		}
+		else if (strcmp (ucl_object_key (elt), "maxItems") == 0
+				&& ucl_object_toint_safe (elt, &minmax)) {
+			if (obj->len > minmax) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+						"array has too many items: %u, maximum is: %u",
+						obj->len, (unsigned)minmax);
+				ret = false;
+				break;
+			}
+		}
+	}
+
+	if (ret) {
+		/* Additional properties */
+		if (!allow_additional || additional_schema != NULL) {
+			if (first_unvalidated != NULL) {
+				if (!allow_additional) {
+					ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+							"array has undefined item");
+					ret = false;
+				}
+				else if (additional_schema != NULL) {
+					elt = first_unvalidated;
+					while (elt) {
+						if (!ucl_schema_validate (additional_schema, elt, false,
+								err, root)) {
+							ret = false;
+							break;
+						}
+						elt = elt->next;
+					}
+				}
+			}
+		}
+		/* Required properties */
+		if (ret && need_unique) {
+			ret = ucl_schema_array_is_unique (obj, err);
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Returns whether this object is allowed for this type
+ */
+static bool
+ucl_schema_type_is_allowed (const ucl_object_t *type, const ucl_object_t *obj,
+		struct ucl_schema_error *err)
+{
+	ucl_object_iter_t iter = NULL;
+	const ucl_object_t *elt;
+	const char *type_str;
+	ucl_type_t t;
+
+	if (type == NULL) {
+		/* Any type is allowed */
+		return true;
+	}
+
+	if (type->type == UCL_ARRAY) {
+		/* One of allowed types */
+		while ((elt = ucl_iterate_object (type, &iter, true)) != NULL) {
+			if (ucl_schema_type_is_allowed (elt, obj, err)) {
+				return true;
+			}
+		}
+	}
+	else if (type->type == UCL_STRING) {
+		type_str = ucl_object_tostring (type);
+		if (!ucl_string_to_type (type_str, &t)) {
+			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, type,
+					"Type attribute is invalid in schema");
+			return false;
+		}
+		if (obj->type != t) {
+			/* Some types are actually compatible */
+			if (obj->type == UCL_TIME && t == UCL_FLOAT) {
+				return true;
+			}
+			else if (obj->type == UCL_INT && t == UCL_FLOAT) {
+				return true;
+			}
+			else {
+				ucl_schema_create_error (err, UCL_SCHEMA_TYPE_MISMATCH, obj,
+						"Invalid type of %s, expected %s",
+						ucl_object_type_to_string (obj->type),
+						ucl_object_type_to_string (t));
+			}
+		}
+		else {
+			/* Types are equal */
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*
+ * Check if object is equal to one of elements of enum
+ */
+static bool
+ucl_schema_validate_enum (const ucl_object_t *en, const ucl_object_t *obj,
+		struct ucl_schema_error *err)
+{
+	ucl_object_iter_t iter = NULL;
+	const ucl_object_t *elt;
+	bool ret = false;
+
+	while ((elt = ucl_iterate_object (en, &iter, true)) != NULL) {
+		if (ucl_object_compare (elt, obj) == 0) {
+			ret = true;
+			break;
+		}
+	}
+
+	if (!ret) {
+		ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+				"object is not one of enumerated patterns");
+	}
+
+	return ret;
+}
+
+
+/*
+ * Check a single ref component
+ */
+static const ucl_object_t *
+ucl_schema_resolve_ref_component (const ucl_object_t *cur,
+		const char *refc, int len,
+		struct ucl_schema_error *err)
+{
+	const ucl_object_t *res = NULL;
+	char *err_str;
+	int num, i;
+
+	if (cur->type == UCL_OBJECT) {
+		/* Find a key inside an object */
+		res = ucl_object_find_keyl (cur, refc, len);
+		if (res == NULL) {
+			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
+					"reference %s is invalid, missing path component", refc);
+			return NULL;
+		}
+	}
+	else if (cur->type == UCL_ARRAY) {
+		/* We must figure out a number inside array */
+		num = strtoul (refc, &err_str, 10);
+		if (err_str != NULL && *err_str != '/' && *err_str != '\0') {
+			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
+					"reference %s is invalid, invalid item number", refc);
+			return NULL;
+		}
+		res = cur->value.av;
+		i = 0;
+		while (res != NULL) {
+			if (i == num) {
+				break;
+			}
+			res = res->next;
+		}
+		if (res == NULL) {
+			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
+					"reference %s is invalid, item number %d does not exist",
+					refc, num);
+			return NULL;
+		}
+	}
+	else {
+		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
+				"reference %s is invalid, contains primitive object in the path",
+				refc);
+		return NULL;
+	}
+
+	return res;
+}
+/*
+ * Find reference schema
+ */
+static const ucl_object_t *
+ucl_schema_resolve_ref (const ucl_object_t *root, const char *ref,
+		struct ucl_schema_error *err)
+{
+	const char *p, *c;
+	const ucl_object_t *res = NULL;
+
+
+	if (ref[0] != '#') {
+		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, root,
+				"reference %s is invalid, not started with #", ref);
+		return NULL;
+	}
+	if (ref[1] == '/') {
+		p = &ref[2];
+	}
+	else if (ref[1] == '\0') {
+		return root;
+	}
+	else {
+		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, root,
+				"reference %s is invalid, not started with #/", ref);
+		return NULL;
+	}
+
+	c = p;
+	res = root;
+
+	while (*p != '\0') {
+		if (*p == '/') {
+			if (p - c == 0) {
+				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
+						"reference %s is invalid, empty path component", ref);
+				return NULL;
+			}
+			/* Now we have some url part, so we need to figure out where we are */
+			res = ucl_schema_resolve_ref_component (res, c, p - c, err);
+			if (res == NULL) {
+				return NULL;
+			}
+			c = p + 1;
+		}
+		p ++;
+	}
+
+	if (p - c != 0) {
+		res = ucl_schema_resolve_ref_component (res, c, p - c, err);
+	}
+
+	if (res == NULL || res->type != UCL_OBJECT) {
+		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
+				"reference %s is invalid, cannot find specified object",
+				ref);
+		return NULL;
+	}
+
+	return res;
+}
+
+static bool
+ucl_schema_validate_values (const ucl_object_t *schema, const ucl_object_t *obj,
+		struct ucl_schema_error *err)
+{
+	const ucl_object_t *elt, *cur;
+	int64_t constraint, i;
+
+	elt = ucl_object_find_key (schema, "maxValues");
+	if (elt != NULL && elt->type == UCL_INT) {
+		constraint = ucl_object_toint (elt);
+		cur = obj;
+		i = 0;
+		while (cur) {
+			if (i > constraint) {
+				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+					"object has more values than defined: %ld",
+					(long int)constraint);
+				return false;
+			}
+			i ++;
+			cur = cur->next;
+		}
+	}
+	elt = ucl_object_find_key (schema, "minValues");
+	if (elt != NULL && elt->type == UCL_INT) {
+		constraint = ucl_object_toint (elt);
+		cur = obj;
+		i = 0;
+		while (cur) {
+			if (i >= constraint) {
+				break;
+			}
+			i ++;
+			cur = cur->next;
+		}
+		if (i < constraint) {
+			ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
+					"object has less values than defined: %ld",
+					(long int)constraint);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool
+ucl_schema_validate (const ucl_object_t *schema,
+		const ucl_object_t *obj, bool try_array,
+		struct ucl_schema_error *err,
+		const ucl_object_t *root)
+{
+	const ucl_object_t *elt, *cur;
+	ucl_object_iter_t iter = NULL;
+	bool ret;
+
+	if (schema->type != UCL_OBJECT) {
+		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, schema,
+				"schema is %s instead of object", ucl_object_type_to_string (schema->type));
+		return false;
+	}
+
+	if (try_array) {
+		/*
+		 * Special case for multiple values
+		 */
+		if (!ucl_schema_validate_values (schema, obj, err)) {
+			return false;
+		}
+		LL_FOREACH (obj, cur) {
+			if (!ucl_schema_validate (schema, cur, false, err, root)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	elt = ucl_object_find_key (schema, "enum");
+	if (elt != NULL && elt->type == UCL_ARRAY) {
+		if (!ucl_schema_validate_enum (elt, obj, err)) {
+			return false;
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "allOf");
+	if (elt != NULL && elt->type == UCL_ARRAY) {
+		iter = NULL;
+		while ((cur = ucl_iterate_object (elt, &iter, true)) != NULL) {
+			ret = ucl_schema_validate (cur, obj, true, err, root);
+			if (!ret) {
+				return false;
+			}
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "anyOf");
+	if (elt != NULL && elt->type == UCL_ARRAY) {
+		iter = NULL;
+		while ((cur = ucl_iterate_object (elt, &iter, true)) != NULL) {
+			ret = ucl_schema_validate (cur, obj, true, err, root);
+			if (ret) {
+				break;
+			}
+		}
+		if (!ret) {
+			return false;
+		}
+		else {
+			/* Reset error */
+			err->code = UCL_SCHEMA_OK;
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "oneOf");
+	if (elt != NULL && elt->type == UCL_ARRAY) {
+		iter = NULL;
+		ret = false;
+		while ((cur = ucl_iterate_object (elt, &iter, true)) != NULL) {
+			if (!ret) {
+				ret = ucl_schema_validate (cur, obj, true, err, root);
+			}
+			else if (ucl_schema_validate (cur, obj, true, err, root)) {
+				ret = false;
+				break;
+			}
+		}
+		if (!ret) {
+			return false;
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "not");
+	if (elt != NULL && elt->type == UCL_OBJECT) {
+		if (ucl_schema_validate (elt, obj, true, err, root)) {
+			return false;
+		}
+		else {
+			/* Reset error */
+			err->code = UCL_SCHEMA_OK;
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "$ref");
+	if (elt != NULL) {
+		cur = ucl_schema_resolve_ref (root, ucl_object_tostring (elt), err);
+		if (cur == NULL) {
+			return false;
+		}
+		if (!ucl_schema_validate (cur, obj, try_array, err, root)) {
+			return false;
+		}
+	}
+
+	elt = ucl_object_find_key (schema, "type");
+	if (!ucl_schema_type_is_allowed (elt, obj, err)) {
+		return false;
+	}
+
+	switch (obj->type) {
+	case UCL_OBJECT:
+		return ucl_schema_validate_object (schema, obj, err, root);
+		break;
+	case UCL_ARRAY:
+		return ucl_schema_validate_array (schema, obj, err, root);
+		break;
+	case UCL_INT:
+	case UCL_FLOAT:
+		return ucl_schema_validate_number (schema, obj, err);
+		break;
+	case UCL_STRING:
+		return ucl_schema_validate_string (schema, obj, err);
+		break;
+	default:
+		break;
+	}
+
+	return true;
+}
+
+bool
+ucl_object_validate (const ucl_object_t *schema,
+		const ucl_object_t *obj, struct ucl_schema_error *err)
+{
+	return ucl_schema_validate (schema, obj, true, err, schema);
+}
diff --git a/contrib/libucl/src/ucl_util.c b/contrib/libucl/src/ucl_util.c
index 34080d4..63f5e62 100644
--- a/contrib/libucl/src/ucl_util.c
+++ b/contrib/libucl/src/ucl_util.c
@@ -25,7 +25,9 @@
 #include "ucl_internal.h"
 #include "ucl_chartable.h"
 
+#ifdef HAVE_LIBGEN_H
 #include <libgen.h> /* For dirname */
+#endif
 
 #ifdef HAVE_OPENSSL
 #include <openssl/err.h>
@@ -35,17 +37,36 @@
 #include <openssl/evp.h>
 #endif
 
+#ifdef CURL_FOUND
+#include <curl/curl.h>
+#endif
+#ifdef HAVE_FETCH_H
+#include <fetch.h>
+#endif
+
 #ifdef _WIN32
 #include <windows.h>
 
+#ifndef PROT_READ
 #define PROT_READ       1
+#endif
+#ifndef PROT_WRITE
 #define PROT_WRITE      2
+#endif
+#ifndef PROT_READWRITE
 #define PROT_READWRITE  3
+#endif
+#ifndef MAP_SHARED
 #define MAP_SHARED      1
+#endif
+#ifndef MAP_PRIVATE
 #define MAP_PRIVATE     2
+#endif
+#ifndef MAP_FAILED
 #define MAP_FAILED      ((void *) -1)
+#endif
 
-static void *mmap(char *addr, size_t length, int prot, int access, int fd, off_t offset)
+static void *ucl_mmap(char *addr, size_t length, int prot, int access, int fd, off_t offset)
 {
 	void *map = NULL;
 	HANDLE handle = INVALID_HANDLE_VALUE;
@@ -83,7 +104,7 @@ static void *mmap(char *addr, size_t length, int prot, int access, int fd, off_t
 	return (void *) ((char *) map + offset);
 }
 
-static int munmap(void *map,size_t length)
+static int ucl_munmap(void *map,size_t length)
 {
 	if (!UnmapViewOfFile(map)) {
 		return(-1);
@@ -91,7 +112,7 @@ static int munmap(void *map,size_t length)
 	return(0);
 }
 
-static char* realpath(const char *path, char *resolved_path) {
+static char* ucl_realpath(const char *path, char *resolved_path) {
     char *p;
     char tmp[MAX_PATH + 1];
     strncpy(tmp, path, sizeof(tmp)-1);
@@ -102,6 +123,10 @@ static char* realpath(const char *path, char *resolved_path) {
     }
     return _fullpath(resolved_path, tmp, MAX_PATH);
 }
+#else
+#define ucl_mmap mmap
+#define ucl_munmap munmap
+#define ucl_realpath realpath
 #endif
 
 /**
@@ -109,35 +134,76 @@ static char* realpath(const char *path, char *resolved_path) {
  * Utilities for rcl parsing
  */
 
+typedef void (*ucl_object_dtor) (ucl_object_t *obj);
+static void ucl_object_free_internal (ucl_object_t *obj, bool allow_rec,
+		ucl_object_dtor dtor);
+static void ucl_object_dtor_unref (ucl_object_t *obj);
 
 static void
-ucl_object_free_internal (ucl_object_t *obj, bool allow_rec)
+ucl_object_dtor_free (ucl_object_t *obj)
 {
-	ucl_object_t *sub, *tmp;
+	if (obj->trash_stack[UCL_TRASH_KEY] != NULL) {
+		UCL_FREE (obj->hh.keylen, obj->trash_stack[UCL_TRASH_KEY]);
+	}
+	if (obj->trash_stack[UCL_TRASH_VALUE] != NULL) {
+		UCL_FREE (obj->len, obj->trash_stack[UCL_TRASH_VALUE]);
+	}
+	UCL_FREE (sizeof (ucl_object_t), obj);
+}
 
-	while (obj != NULL) {
-		if (obj->trash_stack[UCL_TRASH_KEY] != NULL) {
-			UCL_FREE (obj->hh.keylen, obj->trash_stack[UCL_TRASH_KEY]);
-		}
-		if (obj->trash_stack[UCL_TRASH_VALUE] != NULL) {
-			UCL_FREE (obj->len, obj->trash_stack[UCL_TRASH_VALUE]);
+/*
+ * This is a helper function that performs exactly the same as
+ * `ucl_object_unref` but it doesn't iterate over elements allowing
+ * to use it for individual elements of arrays and multiple values
+ */
+static void
+ucl_object_dtor_unref_single (ucl_object_t *obj)
+{
+	if (obj != NULL) {
+#ifdef HAVE_ATOMIC_BUILTINS
+		unsigned int rc = __sync_sub_and_fetch (&obj->ref, 1);
+		if (rc == 0) {
+#else
+		if (--obj->ref == 0) {
+#endif
+			ucl_object_free_internal (obj, false, ucl_object_dtor_unref);
 		}
+	}
+}
 
+static void
+ucl_object_dtor_unref (ucl_object_t *obj)
+{
+	if (obj->ref == 0) {
+		ucl_object_dtor_free (obj);
+	}
+	else {
+		/* This may cause dtor unref being called one more time */
+		ucl_object_dtor_unref_single (obj);
+	}
+}
+
+static void
+ucl_object_free_internal (ucl_object_t *obj, bool allow_rec, ucl_object_dtor dtor)
+{
+	ucl_object_t *sub, *tmp;
+
+	while (obj != NULL) {
 		if (obj->type == UCL_ARRAY) {
 			sub = obj->value.av;
 			while (sub != NULL) {
 				tmp = sub->next;
-				ucl_object_free_internal (sub, false);
+				dtor (sub);
 				sub = tmp;
 			}
 		}
 		else if (obj->type == UCL_OBJECT) {
 			if (obj->value.ov != NULL) {
-				ucl_hash_destroy (obj->value.ov, (ucl_hash_free_func *)ucl_object_unref);
+				ucl_hash_destroy (obj->value.ov, (ucl_hash_free_func *)dtor);
 			}
 		}
 		tmp = obj->next;
-		UCL_FREE (sizeof (ucl_object_t), obj);
+		dtor (obj);
 		obj = tmp;
 
 		if (!allow_rec) {
@@ -149,7 +215,7 @@ ucl_object_free_internal (ucl_object_t *obj, bool allow_rec)
 void
 ucl_object_free (ucl_object_t *obj)
 {
-	ucl_object_free_internal (obj, true);
+	ucl_object_free_internal (obj, true, ucl_object_dtor_free);
 }
 
 size_t
@@ -158,6 +224,9 @@ ucl_unescape_json_string (char *str, size_t len)
 	char *t = str, *h = str;
 	int i, uval;
 
+	if (len <= 1) {
+		return len;
+	}
 	/* t is target (tortoise), h is source (hare) */
 
 	while (len) {
@@ -188,45 +257,53 @@ ucl_unescape_json_string (char *str, size_t len)
 			case 'u':
 				/* Unicode escape */
 				uval = 0;
-				for (i = 0; i < 4; i++) {
-					uval <<= 4;
-					if (isdigit (h[i])) {
-						uval += h[i] - '0';
+				if (len > 3) {
+					for (i = 0; i < 4; i++) {
+						uval <<= 4;
+						if (isdigit (h[i])) {
+							uval += h[i] - '0';
+						}
+						else if (h[i] >= 'a' && h[i] <= 'f') {
+							uval += h[i] - 'a' + 10;
+						}
+						else if (h[i] >= 'A' && h[i] <= 'F') {
+							uval += h[i] - 'A' + 10;
+						}
+						else {
+							break;
+						}
 					}
-					else if (h[i] >= 'a' && h[i] <= 'f') {
-						uval += h[i] - 'a' + 10;
+					h += 3;
+					len -= 3;
+					/* Encode */
+					if(uval < 0x80) {
+						t[0] = (char)uval;
+						t ++;
 					}
-					else if (h[i] >= 'A' && h[i] <= 'F') {
-						uval += h[i] - 'A' + 10;
+					else if(uval < 0x800) {
+						t[0] = 0xC0 + ((uval & 0x7C0) >> 6);
+						t[1] = 0x80 + ((uval & 0x03F));
+						t += 2;
+					}
+					else if(uval < 0x10000) {
+						t[0] = 0xE0 + ((uval & 0xF000) >> 12);
+						t[1] = 0x80 + ((uval & 0x0FC0) >> 6);
+						t[2] = 0x80 + ((uval & 0x003F));
+						t += 3;
+					}
+					else if(uval <= 0x10FFFF) {
+						t[0] = 0xF0 + ((uval & 0x1C0000) >> 18);
+						t[1] = 0x80 + ((uval & 0x03F000) >> 12);
+						t[2] = 0x80 + ((uval & 0x000FC0) >> 6);
+						t[3] = 0x80 + ((uval & 0x00003F));
+						t += 4;
+					}
+					else {
+						*t++ = '?';
 					}
-				}
-				h += 3;
-				len -= 3;
-				/* Encode */
-				if(uval < 0x80) {
-					t[0] = (char)uval;
-					t ++;
-				}
-				else if(uval < 0x800) {
-					t[0] = 0xC0 + ((uval & 0x7C0) >> 6);
-					t[1] = 0x80 + ((uval & 0x03F));
-					t += 2;
-				}
-				else if(uval < 0x10000) {
-					t[0] = 0xE0 + ((uval & 0xF000) >> 12);
-					t[1] = 0x80 + ((uval & 0x0FC0) >> 6);
-					t[2] = 0x80 + ((uval & 0x003F));
-					t += 3;
-				}
-				else if(uval <= 0x10FFFF) {
-					t[0] = 0xF0 + ((uval & 0x1C0000) >> 18);
-					t[1] = 0x80 + ((uval & 0x03F000) >> 12);
-					t[2] = 0x80 + ((uval & 0x000FC0) >> 6);
-					t[3] = 0x80 + ((uval & 0x00003F));
-					t += 4;
 				}
 				else {
-					*t++ = '?';
+					*t++ = 'u';
 				}
 				break;
 			default:
@@ -246,41 +323,54 @@ ucl_unescape_json_string (char *str, size_t len)
 	return (t - str);
 }
 
-UCL_EXTERN char *
-ucl_copy_key_trash (ucl_object_t *obj)
+char *
+ucl_copy_key_trash (const ucl_object_t *obj)
 {
+	ucl_object_t *deconst;
+
+	if (obj == NULL) {
+		return NULL;
+	}
 	if (obj->trash_stack[UCL_TRASH_KEY] == NULL && obj->key != NULL) {
-		obj->trash_stack[UCL_TRASH_KEY] = malloc (obj->keylen + 1);
-		if (obj->trash_stack[UCL_TRASH_KEY] != NULL) {
-			memcpy (obj->trash_stack[UCL_TRASH_KEY], obj->key, obj->keylen);
-			obj->trash_stack[UCL_TRASH_KEY][obj->keylen] = '\0';
+		deconst = __DECONST (ucl_object_t *, obj);
+		deconst->trash_stack[UCL_TRASH_KEY] = malloc (obj->keylen + 1);
+		if (deconst->trash_stack[UCL_TRASH_KEY] != NULL) {
+			memcpy (deconst->trash_stack[UCL_TRASH_KEY], obj->key, obj->keylen);
+			deconst->trash_stack[UCL_TRASH_KEY][obj->keylen] = '\0';
 		}
-		obj->key = obj->trash_stack[UCL_TRASH_KEY];
-		obj->flags |= UCL_OBJECT_ALLOCATED_KEY;
+		deconst->key = obj->trash_stack[UCL_TRASH_KEY];
+		deconst->flags |= UCL_OBJECT_ALLOCATED_KEY;
 	}
 
 	return obj->trash_stack[UCL_TRASH_KEY];
 }
 
-UCL_EXTERN char *
-ucl_copy_value_trash (ucl_object_t *obj)
+char *
+ucl_copy_value_trash (const ucl_object_t *obj)
 {
+	ucl_object_t *deconst;
+
+	if (obj == NULL) {
+		return NULL;
+	}
 	if (obj->trash_stack[UCL_TRASH_VALUE] == NULL) {
+		deconst = __DECONST (ucl_object_t *, obj);
 		if (obj->type == UCL_STRING) {
+
 			/* Special case for strings */
-			obj->trash_stack[UCL_TRASH_VALUE] = malloc (obj->len + 1);
-			if (obj->trash_stack[UCL_TRASH_VALUE] != NULL) {
-				memcpy (obj->trash_stack[UCL_TRASH_VALUE], obj->value.sv, obj->len);
-				obj->trash_stack[UCL_TRASH_VALUE][obj->len] = '\0';
-				obj->value.sv = obj->trash_stack[UCL_TRASH_VALUE];
+			deconst->trash_stack[UCL_TRASH_VALUE] = malloc (obj->len + 1);
+			if (deconst->trash_stack[UCL_TRASH_VALUE] != NULL) {
+				memcpy (deconst->trash_stack[UCL_TRASH_VALUE], obj->value.sv, obj->len);
+				deconst->trash_stack[UCL_TRASH_VALUE][obj->len] = '\0';
+				deconst->value.sv = obj->trash_stack[UCL_TRASH_VALUE];
 			}
 		}
 		else {
 			/* Just emit value in json notation */
-			obj->trash_stack[UCL_TRASH_VALUE] = ucl_object_emit_single_json (obj);
-			obj->len = strlen (obj->trash_stack[UCL_TRASH_VALUE]);
+			deconst->trash_stack[UCL_TRASH_VALUE] = ucl_object_emit_single_json (obj);
+			deconst->len = strlen (obj->trash_stack[UCL_TRASH_VALUE]);
 		}
-		obj->flags |= UCL_OBJECT_ALLOCATED_VALUE;
+		deconst->flags |= UCL_OBJECT_ALLOCATED_VALUE;
 	}
 	return obj->trash_stack[UCL_TRASH_VALUE];
 }
@@ -304,6 +394,10 @@ ucl_parser_free (struct ucl_parser *parser)
 	struct ucl_pubkey *key, *ktmp;
 	struct ucl_variable *var, *vtmp;
 
+	if (parser == NULL) {
+		return;
+	}
+
 	if (parser->top_obj != NULL) {
 		ucl_object_unref (parser->top_obj);
 	}
@@ -338,6 +432,10 @@ ucl_parser_free (struct ucl_parser *parser)
 UCL_EXTERN const char *
 ucl_parser_get_error(struct ucl_parser *parser)
 {
+	if (parser == NULL) {
+		return NULL;
+	}
+
 	if (parser->err == NULL)
 		return NULL;
 
@@ -360,6 +458,10 @@ ucl_pubkey_add (struct ucl_parser *parser, const unsigned char *key, size_t len)
 
 	mem = BIO_new_mem_buf ((void *)key, len);
 	nkey = UCL_ALLOC (sizeof (struct ucl_pubkey));
+	if (nkey == NULL) {
+		ucl_create_err (&parser->err, "cannot allocate memory for key");
+		return false;
+	}
 	nkey->key = PEM_read_bio_PUBKEY (mem, &nkey->key, NULL, NULL);
 	BIO_free (mem);
 	if (nkey->key == NULL) {
@@ -527,7 +629,7 @@ ucl_fetch_file (const unsigned char *filename, unsigned char **buf, size_t *bufl
 					filename, strerror (errno));
 			return false;
 		}
-		if ((*buf = mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+		if ((*buf = ucl_mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
 			close (fd);
 			ucl_create_err (err, "cannot mmap file %s: %s",
 					filename, strerror (errno));
@@ -629,12 +731,12 @@ ucl_include_url (const unsigned char *data, size_t len,
 							urlbuf,
 							ERR_error_string (ERR_get_error (), NULL));
 			if (siglen > 0) {
-				munmap (sigbuf, siglen);
+				ucl_munmap (sigbuf, siglen);
 			}
 			return false;
 		}
 		if (siglen > 0) {
-			munmap (sigbuf, siglen);
+			ucl_munmap (sigbuf, siglen);
 		}
 #endif
 	}
@@ -678,7 +780,7 @@ ucl_include_file (const unsigned char *data, size_t len,
 	int prev_state;
 
 	snprintf (filebuf, sizeof (filebuf), "%.*s", (int)len, data);
-	if (realpath (filebuf, realbuf) == NULL) {
+	if (ucl_realpath (filebuf, realbuf) == NULL) {
 		if (!must_exist) {
 			return true;
 		}
@@ -706,12 +808,12 @@ ucl_include_file (const unsigned char *data, size_t len,
 							filebuf,
 							ERR_error_string (ERR_get_error (), NULL));
 			if (siglen > 0) {
-				munmap (sigbuf, siglen);
+				ucl_munmap (sigbuf, siglen);
 			}
 			return false;
 		}
 		if (siglen > 0) {
-			munmap (sigbuf, siglen);
+			ucl_munmap (sigbuf, siglen);
 		}
 #endif
 	}
@@ -734,7 +836,7 @@ ucl_include_file (const unsigned char *data, size_t len,
 	parser->state = prev_state;
 
 	if (buflen > 0) {
-		munmap (buf, buflen);
+		ucl_munmap (buf, buflen);
 	}
 
 	return res;
@@ -803,7 +905,7 @@ ucl_parser_set_filevars (struct ucl_parser *parser, const char *filename, bool n
 
 	if (filename != NULL) {
 		if (need_expand) {
-			if (realpath (filename, realbuf) == NULL) {
+			if (ucl_realpath (filename, realbuf) == NULL) {
 				return false;
 			}
 		}
@@ -834,7 +936,7 @@ ucl_parser_add_file (struct ucl_parser *parser, const char *filename)
 	bool ret;
 	char realbuf[PATH_MAX];
 
-	if (realpath (filename, realbuf) == NULL) {
+	if (ucl_realpath (filename, realbuf) == NULL) {
 		ucl_create_err (&parser->err, "cannot open file %s: %s",
 				filename,
 				strerror (errno));
@@ -849,7 +951,7 @@ ucl_parser_add_file (struct ucl_parser *parser, const char *filename)
 	ret = ucl_parser_add_chunk (parser, buf, len);
 
 	if (len > 0) {
-		munmap (buf, len);
+		ucl_munmap (buf, len);
 	}
 
 	return ret;
@@ -1014,13 +1116,15 @@ ucl_object_fromstring_common (const char *str, size_t len, enum ucl_string_flags
 				if (!ucl_maybe_parse_boolean (obj, dst, obj->len) && (flags & UCL_STRING_PARSE_NUMBER)) {
 					ucl_maybe_parse_number (obj, dst, dst + obj->len, &pos,
 							flags & UCL_STRING_PARSE_DOUBLE,
-							flags & UCL_STRING_PARSE_BYTES);
+							flags & UCL_STRING_PARSE_BYTES,
+							flags & UCL_STRING_PARSE_TIME);
 				}
 			}
 			else {
 				ucl_maybe_parse_number (obj, dst, dst + obj->len, &pos,
 						flags & UCL_STRING_PARSE_DOUBLE,
-						flags & UCL_STRING_PARSE_BYTES);
+						flags & UCL_STRING_PARSE_BYTES,
+						flags & UCL_STRING_PARSE_TIME);
 			}
 		}
 	}
@@ -1028,21 +1132,22 @@ ucl_object_fromstring_common (const char *str, size_t len, enum ucl_string_flags
 	return obj;
 }
 
-static ucl_object_t *
+static bool
 ucl_object_insert_key_common (ucl_object_t *top, ucl_object_t *elt,
 		const char *key, size_t keylen, bool copy_key, bool merge, bool replace)
 {
-	ucl_object_t *found, *cur;
+	ucl_object_t *found, *tmp;
+	const ucl_object_t *cur;
 	ucl_object_iter_t it = NULL;
 	const char *p;
+	int ret = true;
 
 	if (elt == NULL || key == NULL) {
-		return NULL;
+		return false;
 	}
 
 	if (top == NULL) {
-		top = ucl_object_new ();
-		top->type = UCL_OBJECT;
+		return false;
 	}
 
 	if (top->type != UCL_OBJECT) {
@@ -1052,7 +1157,7 @@ ucl_object_insert_key_common (ucl_object_t *top, ucl_object_t *elt,
 		}
 		else {
 			/* Refuse converting of other object types */
-			return top;
+			return false;
 		}
 	}
 
@@ -1078,11 +1183,15 @@ ucl_object_insert_key_common (ucl_object_t *top, ucl_object_t *elt,
 		ucl_copy_key_trash (elt);
 	}
 
-	found = ucl_hash_search_obj (top->value.ov, elt);
+	found = __DECONST (ucl_object_t *, ucl_hash_search_obj (top->value.ov, elt));
 
 	if (!found) {
 		top->value.ov = ucl_hash_insert_object (top->value.ov, elt);
 		DL_APPEND (found, elt);
+		top->len ++;
+		if (replace) {
+			ret = false;
+		}
 	}
 	else {
 		if (replace) {
@@ -1095,19 +1204,22 @@ ucl_object_insert_key_common (ucl_object_t *top, ucl_object_t *elt,
 		else if (merge) {
 			if (found->type != UCL_OBJECT && elt->type == UCL_OBJECT) {
 				/* Insert old elt to new one */
-				elt = ucl_object_insert_key_common (elt, found, found->key, found->keylen, copy_key, false, false);
+				ucl_object_insert_key_common (elt, found, found->key,
+						found->keylen, copy_key, false, false);
 				ucl_hash_delete (top->value.ov, found);
 				top->value.ov = ucl_hash_insert_object (top->value.ov, elt);
 			}
 			else if (found->type == UCL_OBJECT && elt->type != UCL_OBJECT) {
 				/* Insert new to old */
-				found = ucl_object_insert_key_common (found, elt, elt->key, elt->keylen, copy_key, false, false);
+				ucl_object_insert_key_common (found, elt, elt->key,
+						elt->keylen, copy_key, false, false);
 			}
 			else if (found->type == UCL_OBJECT && elt->type == UCL_OBJECT) {
 				/* Mix two hashes */
 				while ((cur = ucl_iterate_object (elt, &it, true)) != NULL) {
-					ucl_object_ref (cur);
-					found = ucl_object_insert_key_common (found, cur, cur->key, cur->keylen, copy_key, false, false);
+					tmp = ucl_object_ref (cur);
+					ucl_object_insert_key_common (found, tmp, cur->key,
+							cur->keylen, copy_key, false, false);
 				}
 				ucl_object_unref (elt);
 			}
@@ -1121,20 +1233,25 @@ ucl_object_insert_key_common (ucl_object_t *top, ucl_object_t *elt,
 		}
 	}
 
-	return top;
+	return ret;
 }
 
 bool
-ucl_object_delete_keyl(ucl_object_t *top, const char *key, size_t keylen)
+ucl_object_delete_keyl (ucl_object_t *top, const char *key, size_t keylen)
 {
 	ucl_object_t *found;
 
-	found = ucl_object_find_keyl(top, key, keylen);
+	if (top == NULL || key == NULL) {
+		return false;
+	}
+
+	found = __DECONST (ucl_object_t *, ucl_object_find_keyl (top, key, keylen));
 
-	if (found == NULL)
+	if (found == NULL) {
 		return false;
+	}
 
-	ucl_hash_delete(top->value.ov, found);
+	ucl_hash_delete (top->value.ov, found);
 	ucl_object_unref (found);
 	top->len --;
 
@@ -1142,36 +1259,62 @@ ucl_object_delete_keyl(ucl_object_t *top, const char *key, size_t keylen)
 }
 
 bool
-ucl_object_delete_key(ucl_object_t *top, const char *key)
+ucl_object_delete_key (ucl_object_t *top, const char *key)
 {
-	return ucl_object_delete_keyl(top, key, 0);
+	return ucl_object_delete_keyl (top, key, strlen(key));
 }
 
-ucl_object_t *
+ucl_object_t*
+ucl_object_pop_keyl (ucl_object_t *top, const char *key, size_t keylen)
+{
+	const ucl_object_t *found;
+
+	if (top == NULL || key == NULL) {
+		return false;
+	}
+	found = ucl_object_find_keyl (top, key, keylen);
+
+	if (found == NULL) {
+		return NULL;
+	}
+	ucl_hash_delete (top->value.ov, found);
+	top->len --;
+
+	return __DECONST (ucl_object_t *, found);
+}
+
+ucl_object_t*
+ucl_object_pop_key (ucl_object_t *top, const char *key)
+{
+	return ucl_object_pop_keyl (top, key, strlen(key));
+}
+
+bool
 ucl_object_insert_key (ucl_object_t *top, ucl_object_t *elt,
 		const char *key, size_t keylen, bool copy_key)
 {
 	return ucl_object_insert_key_common (top, elt, key, keylen, copy_key, false, false);
 }
 
-ucl_object_t *
+bool
 ucl_object_insert_key_merged (ucl_object_t *top, ucl_object_t *elt,
 		const char *key, size_t keylen, bool copy_key)
 {
 	return ucl_object_insert_key_common (top, elt, key, keylen, copy_key, true, false);
 }
 
-ucl_object_t *
+bool
 ucl_object_replace_key (ucl_object_t *top, ucl_object_t *elt,
 		const char *key, size_t keylen, bool copy_key)
 {
 	return ucl_object_insert_key_common (top, elt, key, keylen, copy_key, false, true);
 }
 
-ucl_object_t *
-ucl_object_find_keyl (ucl_object_t *obj, const char *key, size_t klen)
+const ucl_object_t *
+ucl_object_find_keyl (const ucl_object_t *obj, const char *key, size_t klen)
 {
-	ucl_object_t *ret, srch;
+	const ucl_object_t *ret;
+	ucl_object_t srch;
 
 	if (obj == NULL || obj->type != UCL_OBJECT || key == NULL) {
 		return NULL;
@@ -1184,33 +1327,28 @@ ucl_object_find_keyl (ucl_object_t *obj, const char *key, size_t klen)
 	return ret;
 }
 
-ucl_object_t *
-ucl_object_find_key (ucl_object_t *obj, const char *key)
+const ucl_object_t *
+ucl_object_find_key (const ucl_object_t *obj, const char *key)
 {
-	size_t klen;
-	ucl_object_t *ret, srch;
-
-	if (obj == NULL || obj->type != UCL_OBJECT || key == NULL) {
+	if (key == NULL)
 		return NULL;
-	}
-
-	klen = strlen (key);
-	srch.key = key;
-	srch.keylen = klen;
-	ret = ucl_hash_search_obj (obj->value.ov, &srch);
 
-	return ret;
+	return ucl_object_find_keyl (obj, key, strlen(key));
 }
 
-ucl_object_t*
-ucl_iterate_object (ucl_object_t *obj, ucl_object_iter_t *iter, bool expand_values)
+const ucl_object_t*
+ucl_iterate_object (const ucl_object_t *obj, ucl_object_iter_t *iter, bool expand_values)
 {
-	ucl_object_t *elt;
+	const ucl_object_t *elt;
+
+	if (obj == NULL || iter == NULL) {
+		return NULL;
+	}
 
 	if (expand_values) {
 		switch (obj->type) {
 		case UCL_OBJECT:
-			return (ucl_object_t*)ucl_hash_iterate (obj->value.ov, iter);
+			return (const ucl_object_t*)ucl_hash_iterate (obj->value.ov, iter);
 			break;
 		case UCL_ARRAY:
 			elt = *iter;
@@ -1241,9 +1379,580 @@ ucl_iterate_object (ucl_object_t *obj, ucl_object_iter_t *iter, bool expand_valu
 	else if (elt == obj) {
 		return NULL;
 	}
-	*iter = elt->next ? elt->next : obj;
+	*iter = __DECONST (void *, elt->next ? elt->next : obj);
 	return elt;
 
 	/* Not reached */
 	return NULL;
 }
+
+const ucl_object_t *
+ucl_lookup_path (const ucl_object_t *top, const char *path_in) {
+	const ucl_object_t *o = NULL, *found;
+	const char *p, *c;
+	char *err_str;
+	unsigned index;
+
+	if (path_in == NULL || top == NULL) {
+		return NULL;
+	}
+
+	found = NULL;
+	p = path_in;
+
+	/* Skip leading dots */
+	while (*p == '.') {
+		p ++;
+	}
+
+	c = p;
+	while (*p != '\0') {
+		p ++;
+		if (*p == '.' || *p == '\0') {
+			if (p > c) {
+				switch (top->type) {
+				case UCL_ARRAY:
+					/* Key should be an int */
+					index = strtoul (c, &err_str, 10);
+					if (err_str != NULL && (*err_str != '.' && *err_str != '\0')) {
+						return NULL;
+					}
+					o = ucl_array_find_index (top, index);
+					break;
+				default:
+					o = ucl_object_find_keyl (top, c, p - c);
+					break;
+				}
+				if (o == NULL) {
+					return NULL;
+				}
+				top = o;
+			}
+			if (*p != '\0') {
+				c = p + 1;
+			}
+		}
+	}
+	found = o;
+
+	return found;
+}
+
+
+ucl_object_t *
+ucl_object_new (void)
+{
+	ucl_object_t *new;
+	new = malloc (sizeof (ucl_object_t));
+	if (new != NULL) {
+		memset (new, 0, sizeof (ucl_object_t));
+		new->ref = 1;
+		new->type = UCL_NULL;
+	}
+	return new;
+}
+
+ucl_object_t *
+ucl_object_typed_new (ucl_type_t type)
+{
+	ucl_object_t *new;
+	new = malloc (sizeof (ucl_object_t));
+	if (new != NULL) {
+		memset (new, 0, sizeof (ucl_object_t));
+		new->ref = 1;
+		new->type = (type <= UCL_NULL ? type : UCL_NULL);
+	}
+	return new;
+}
+
+ucl_type_t
+ucl_object_type (const ucl_object_t *obj)
+{
+	return obj->type;
+}
+
+ucl_object_t*
+ucl_object_fromstring (const char *str)
+{
+	return ucl_object_fromstring_common (str, 0, UCL_STRING_ESCAPE);
+}
+
+ucl_object_t *
+ucl_object_fromlstring (const char *str, size_t len)
+{
+	return ucl_object_fromstring_common (str, len, UCL_STRING_ESCAPE);
+}
+
+ucl_object_t *
+ucl_object_fromint (int64_t iv)
+{
+	ucl_object_t *obj;
+
+	obj = ucl_object_new ();
+	if (obj != NULL) {
+		obj->type = UCL_INT;
+		obj->value.iv = iv;
+	}
+
+	return obj;
+}
+
+ucl_object_t *
+ucl_object_fromdouble (double dv)
+{
+	ucl_object_t *obj;
+
+	obj = ucl_object_new ();
+	if (obj != NULL) {
+		obj->type = UCL_FLOAT;
+		obj->value.dv = dv;
+	}
+
+	return obj;
+}
+
+ucl_object_t*
+ucl_object_frombool (bool bv)
+{
+	ucl_object_t *obj;
+
+	obj = ucl_object_new ();
+	if (obj != NULL) {
+		obj->type = UCL_BOOLEAN;
+		obj->value.iv = bv;
+	}
+
+	return obj;
+}
+
+bool
+ucl_array_append (ucl_object_t *top, ucl_object_t *elt)
+{
+	ucl_object_t *head;
+
+	if (elt == NULL || top == NULL) {
+		return false;
+	}
+
+	head = top->value.av;
+	if (head == NULL) {
+		top->value.av = elt;
+		elt->prev = elt;
+	}
+	else {
+		elt->prev = head->prev;
+		head->prev->next = elt;
+		head->prev = elt;
+	}
+	elt->next = NULL;
+	top->len ++;
+
+	return true;
+}
+
+bool
+ucl_array_prepend (ucl_object_t *top, ucl_object_t *elt)
+{
+	ucl_object_t *head;
+
+	if (elt == NULL || top == NULL) {
+		return false;
+	}
+
+
+	head = top->value.av;
+	if (head == NULL) {
+		top->value.av = elt;
+		elt->prev = elt;
+	}
+	else {
+		elt->prev = head->prev;
+		head->prev = elt;
+	}
+	elt->next = head;
+	top->value.av = elt;
+	top->len ++;
+
+	return true;
+}
+
+ucl_object_t *
+ucl_array_delete (ucl_object_t *top, ucl_object_t *elt)
+{
+	ucl_object_t *head;
+
+	if (top == NULL || top->type != UCL_ARRAY || top->value.av == NULL) {
+		return NULL;
+	}
+	head = top->value.av;
+
+	if (elt->prev == elt) {
+		top->value.av = NULL;
+	}
+	else if (elt == head) {
+		elt->next->prev = elt->prev;
+		top->value.av = elt->next;
+	}
+	else {
+		elt->prev->next = elt->next;
+		if (elt->next) {
+			elt->next->prev = elt->prev;
+		}
+		else {
+			head->prev = elt->prev;
+		}
+	}
+	elt->next = NULL;
+	elt->prev = elt;
+	top->len --;
+
+	return elt;
+}
+
+const ucl_object_t *
+ucl_array_head (const ucl_object_t *top)
+{
+	if (top == NULL || top->type != UCL_ARRAY || top->value.av == NULL) {
+		return NULL;
+	}
+	return top->value.av;
+}
+
+const ucl_object_t *
+ucl_array_tail (const ucl_object_t *top)
+{
+	if (top == NULL || top->type != UCL_ARRAY || top->value.av == NULL) {
+		return NULL;
+	}
+	return top->value.av->prev;
+}
+
+ucl_object_t *
+ucl_array_pop_last (ucl_object_t *top)
+{
+	return ucl_array_delete (top, __DECONST(ucl_object_t *, ucl_array_tail (top)));
+}
+
+ucl_object_t *
+ucl_array_pop_first (ucl_object_t *top)
+{
+	return ucl_array_delete (top, __DECONST(ucl_object_t *, ucl_array_head (top)));
+}
+
+const ucl_object_t *
+ucl_array_find_index (const ucl_object_t *top, unsigned int index)
+{
+	ucl_object_iter_t it = NULL;
+	const ucl_object_t *ret;
+
+	if (top == NULL || top->type != UCL_ARRAY || top->len == 0 ||
+	    (index + 1) > top->len) {
+		return NULL;
+	}
+
+	while ((ret = ucl_iterate_object (top, &it, true)) != NULL) {
+		if (index == 0) {
+			return ret;
+		}
+		--index;
+	}
+
+	return NULL;
+}
+
+ucl_object_t *
+ucl_elt_append (ucl_object_t *head, ucl_object_t *elt)
+{
+
+	if (head == NULL) {
+		elt->next = NULL;
+		elt->prev = elt;
+		head = elt;
+	}
+	else {
+		elt->prev = head->prev;
+		head->prev->next = elt;
+		head->prev = elt;
+		elt->next = NULL;
+	}
+
+	return head;
+}
+
+bool
+ucl_object_todouble_safe (const ucl_object_t *obj, double *target)
+{
+	if (obj == NULL || target == NULL) {
+		return false;
+	}
+	switch (obj->type) {
+	case UCL_INT:
+		*target = obj->value.iv; /* Probaly could cause overflow */
+		break;
+	case UCL_FLOAT:
+	case UCL_TIME:
+		*target = obj->value.dv;
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+double
+ucl_object_todouble (const ucl_object_t *obj)
+{
+	double result = 0.;
+
+	ucl_object_todouble_safe (obj, &result);
+	return result;
+}
+
+bool
+ucl_object_toint_safe (const ucl_object_t *obj, int64_t *target)
+{
+	if (obj == NULL || target == NULL) {
+		return false;
+	}
+	switch (obj->type) {
+	case UCL_INT:
+		*target = obj->value.iv;
+		break;
+	case UCL_FLOAT:
+	case UCL_TIME:
+		*target = obj->value.dv; /* Loosing of decimal points */
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+int64_t
+ucl_object_toint (const ucl_object_t *obj)
+{
+	int64_t result = 0;
+
+	ucl_object_toint_safe (obj, &result);
+	return result;
+}
+
+bool
+ucl_object_toboolean_safe (const ucl_object_t *obj, bool *target)
+{
+	if (obj == NULL || target == NULL) {
+		return false;
+	}
+	switch (obj->type) {
+	case UCL_BOOLEAN:
+		*target = (obj->value.iv == true);
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+bool
+ucl_object_toboolean (const ucl_object_t *obj)
+{
+	bool result = false;
+
+	ucl_object_toboolean_safe (obj, &result);
+	return result;
+}
+
+bool
+ucl_object_tostring_safe (const ucl_object_t *obj, const char **target)
+{
+	if (obj == NULL || target == NULL) {
+		return false;
+	}
+
+	switch (obj->type) {
+	case UCL_STRING:
+		*target = ucl_copy_value_trash (obj);
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+const char *
+ucl_object_tostring (const ucl_object_t *obj)
+{
+	const char *result = NULL;
+
+	ucl_object_tostring_safe (obj, &result);
+	return result;
+}
+
+const char *
+ucl_object_tostring_forced (const ucl_object_t *obj)
+{
+	return ucl_copy_value_trash (obj);
+}
+
+bool
+ucl_object_tolstring_safe (const ucl_object_t *obj, const char **target, size_t *tlen)
+{
+	if (obj == NULL || target == NULL) {
+		return false;
+	}
+	switch (obj->type) {
+	case UCL_STRING:
+		*target = obj->value.sv;
+		if (tlen != NULL) {
+			*tlen = obj->len;
+		}
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+const char *
+ucl_object_tolstring (const ucl_object_t *obj, size_t *tlen)
+{
+	const char *result = NULL;
+
+	ucl_object_tolstring_safe (obj, &result, tlen);
+	return result;
+}
+
+const char *
+ucl_object_key (const ucl_object_t *obj)
+{
+	return ucl_copy_key_trash (obj);
+}
+
+const char *
+ucl_object_keyl (const ucl_object_t *obj, size_t *len)
+{
+	if (len == NULL || obj == NULL) {
+		return NULL;
+	}
+	*len = obj->keylen;
+	return obj->key;
+}
+
+ucl_object_t *
+ucl_object_ref (const ucl_object_t *obj)
+{
+	ucl_object_t *res = NULL;
+
+	if (obj != NULL) {
+		res = __DECONST (ucl_object_t *, obj);
+#ifdef HAVE_ATOMIC_BUILTINS
+		(void)__sync_add_and_fetch (&res->ref, 1);
+#else
+		res->ref ++;
+#endif
+	}
+	return res;
+}
+
+void
+ucl_object_unref (ucl_object_t *obj)
+{
+	if (obj != NULL) {
+#ifdef HAVE_ATOMIC_BUILTINS
+		unsigned int rc = __sync_sub_and_fetch (&obj->ref, 1);
+		if (rc == 0) {
+#else
+		if (--obj->ref == 0) {
+#endif
+			ucl_object_free_internal (obj, true, ucl_object_dtor_unref);
+		}
+	}
+}
+
+int
+ucl_object_compare (const ucl_object_t *o1, const ucl_object_t *o2)
+{
+	const ucl_object_t *it1, *it2;
+	ucl_object_iter_t iter = NULL;
+	int ret = 0;
+
+	if (o1->type != o2->type) {
+		return (o1->type) - (o2->type);
+	}
+
+	switch (o1->type) {
+	case UCL_STRING:
+		if (o1->len == o2->len) {
+			ret = strcmp (ucl_object_tostring(o1), ucl_object_tostring(o2));
+		}
+		else {
+			ret = o1->len - o2->len;
+		}
+		break;
+	case UCL_FLOAT:
+	case UCL_INT:
+	case UCL_TIME:
+		ret = ucl_object_todouble (o1) - ucl_object_todouble (o2);
+		break;
+	case UCL_BOOLEAN:
+		ret = ucl_object_toboolean (o1) - ucl_object_toboolean (o2);
+		break;
+	case UCL_ARRAY:
+		if (o1->len == o2->len) {
+			it1 = o1->value.av;
+			it2 = o2->value.av;
+			/* Compare all elements in both arrays */
+			while (it1 != NULL && it2 != NULL) {
+				ret = ucl_object_compare (it1, it2);
+				if (ret != 0) {
+					break;
+				}
+				it1 = it1->next;
+				it2 = it2->next;
+			}
+		}
+		else {
+			ret = o1->len - o2->len;
+		}
+		break;
+	case UCL_OBJECT:
+		if (o1->len == o2->len) {
+			while ((it1 = ucl_iterate_object (o1, &iter, true)) != NULL) {
+				it2 = ucl_object_find_key (o2, ucl_object_key (it1));
+				if (it2 == NULL) {
+					ret = 1;
+					break;
+				}
+				ret = ucl_object_compare (it1, it2);
+				if (ret != 0) {
+					break;
+				}
+			}
+		}
+		else {
+			ret = o1->len - o2->len;
+		}
+		break;
+	default:
+		ret = 0;
+		break;
+	}
+
+	return ret;
+}
+
+void
+ucl_object_array_sort (ucl_object_t *ar,
+		int (*cmp)(const ucl_object_t *o1, const ucl_object_t *o2))
+{
+	if (cmp == NULL || ar == NULL || ar->type != UCL_ARRAY) {
+		return;
+	}
+
+	DL_SORT (ar->value.av, cmp);
+}