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/**
* @page transition Transition Manual (1.x -> 2.0)
*
* [TOC]
*
* Rewriting libyang codebase and creating libyang version 2.0 was motivated mainly by improving long term maintainability.
* Especially some of the features and design decisions become killers for further development and maintaining the libyang
* codebase. On the other hand, most of the principles introduced in libyang 1.x to handle YANG schemas and manipulate
* instantiated data have proved successful. Therefore, we have decided to keep the basic mechanisms from version 1.x and
* remove the problematic features and modify the improper design decisions. Despite the vision to keep with the mechanisms
* also the API, the new version became a great opportunity to clean up the API and improve its usability mainly by unifying
* how the libyang functions are used. So, in the end, this manual is not just a description of the removed features listing
* removed, modified or added functions. The API should be even better prepared for adding new features and functions.
* Shortly, almost everything has changed at least a little, so you cannot move from version 1.x to 2.0 just by replacing
* code snippets. However, we believe that the change is good and libyang 2.0 is simply better.
*
* In this Manual, we want to introduce the differences between libyang 1.x and 2.0. It is intended for the transition
* from 1.x to 2.0, so if you are new to libyang, simply go to the @ref howto section, this Manual is not for you.
*
* The complete generated list of changes (without any additional notes) can be found in
* <a href="../compat_report.html">the compatibility report</a>.
*
* @section transitionGeneral General Changes
*
*
* @subsection transitionGeneralErros Errors Handling
*
* The most visible change is probably the changed approach to handling errors. While libyang 1.x was using variable
* *ly_errno* to provide error information in case the called function failed, there is no such variable in libyang 2.0.
* On the other hand, most API functions now return ::LY_ERR values directly stating the result. In addition, in case
* the error is somehow connected with the [context](@ref howtoContext), more detailed error information can be obtained
* from the context handler itself. Mainly this change is responsible for the backward incompatibility of almost all
* functions between versions 1.x and 2.0.
*
* Here is the overview of the changed / removed / added functions connected with errors and logging.
*
* libyang 1.x | libyang 2.0 | Notes
* :-------------------------|:-------------------------------------|:-------------------------------------------------------
* - | ::ly_err_last() | New API for handling errors.
* - | ::ly_errcode() | ^
* ly_verb_dbg() | ::ly_log_dbg_groups() | Rename to align with the names of the accepted values.
* ly_verb() | ::ly_log_level() | ^
*
* More information about error handling in libyang 2.0 can be found at @ref howtoErrors page.
*
* @subsection transitionGeneralInOut Input / Output Processing
*
* libyang 2.0 introduces input (::ly_in) and output (::ly_out) handlers covering the specific input sources for parsers and
* output targets for printers. They are supposed mainly to simplify parser's and printer's API to avoid the need for
* separate functions for each source/target. The handlers can be used repeatedly to split the inputs or join the outputs.
*
* More information can be found at @ref howtoInput and @ref howtoOutput pages.
*
*
* @subsection transitionGeneralOutputFormatting Output Formatting
*
* In libyang 1.x, there was an inconsistency in printing schemas and data. While the schemas were always printed formatted,
* the data were printed by default without additional indentation. It is clearly visible in the YIN format of the schema,
* which is XML, and the XML encoding of the data. While there was a possibility to format data output with the LYP_FORMAT
* flag, it wasn't possible to change schema output formatting.
*
* libyang 2.0 unifies the behavior of all printers. By default, all the output formats are formatted now. Both, the data as
* well as the schema printers, accept the option to remove additional formatting (different for the specific format, usually
* indentations and blank lines): ::LYD_PRINT_SHRINK for the data printer and ::LYS_PRINT_SHRINK for the schema printer.
*
*
* @subsection transitionGeneralXPath Addressing
*
* If you compare the @ref howtoXPath page from libyang 1.x and 2.0 documentation, you will be probably confused since they
* seem very different. In fact, we have tried to simplify the API by removing the original Schema path format from the
* public API. Since this format is used in YANG format, libyang still supports it internally, but it is not possible to use
* it anywhere in the API. The new formats XPath and Path, mentioned at the @ref howtoXPath page, are both the Data paths
* used in libyang 1.x. The Path format is a subset of XPath format limited to refer to a single node.
*
* This change was reflected in functions serving to get a node based on the specified path. Unfortunately, when comparing
* old and new API, the transition can be confusing since the names are sometimes overloaded (be careful mainly of
* ::lys_find_path()). The following table depicts the changes, but probably a better approach is to handle the functions as
* a completely new API.
*
* libyang 1.x | libyang 2.0 | Notes
* :-------------------------|:-------------------------------------|:-------------------------------------------------------
* ly_ctx_find_path() | - | To simplify the different [types of paths](@ref howtoXPath), the Schema path format is not supported for now. If there will be use cases for it, it can be re-added later, but for now try using ::lys_find_xpath().
* %lys_find_path() | - | To simplify the different [types of paths](@ref howtoXPath), the Schema path format is not supported for now. If there will be use cases for it, it can be re-added later, but for now try using ::lys_find_xpath().
* ly_ctx_get_node() | ::lys_find_path() | Renamed to unify API functions, note that there was lys_find_path in libyang 1.x with different functionality in comparison to the function of the same name from libyang 2.0.
* - | ::lys_find_path_atoms() | Extension of ::lys_find_path().
* - | ::lys_find_lypath_atoms() | ^
* - | ::lys_find_xpath() | New function reflecting updated @ref howtoXPath\.
* lys_xpath_atomize() | ::lys_find_xpath_atoms() | Rename to unify with the new API, extends ::lys_find_xpath().
* - | ::lys_find_expr_atoms() | Extension of ::lys_find_xpath().
* %lyd_path() | ::lyd_path() | Same purpose, just extended functionality.
* lyd_find_path() | ::lyd_find_xpath() | Rename to unify with the new API.
* - | ::lyd_find_path() | Simplified version of ::lyd_find_path().
* - | ::lyxp_get_expr() | Added functionality due to the changed representation of XPath expressions.
* ly_path_data2schema() | - | Removed since the schema path is not available in API.
* ly_path_xml2json() | - | Removed since done internally, note that even the generic XML parser is not available now.
* lys_node_xpath_atomize() | - | Removed as useless/redundant, use ::lys_find_xpath_atoms().
*
* @section transitionContext Context
*
* Context, as a concept of a storage interconnecting YANG modules into a YANG schema and YANG schema with the instantiated
* data, was preserved. However, it is now more supposed to be prepared just once before connecting it with any instantiated
* data. The possibility of removing YANG modules from the context was completely dropped. Furthermore, we would like to
* introduce some kind of context lock to completely abandon any change of the YANG modules after starting work with the
* instantiated data.
*
* Other significant changes connected with the context are depicted in the following table.
*
* libyang 1.x | libyang 2.0 | Notes
* :-------------------------|:-------------------------------------|:-------------------------------------------------------
* ly_ctx_clean() | - | Removed functionality of manipulating with the context and the modules already placed in the context.
* ly_ctx_remove_module() | - | ^
* ly_ctx_set_module_data_clb() and the associated ly_module_data_clb type. | - | ^
* ly_ctx_get_disabled_module() and the associated ly_ctx_get_disabled_module_iter() | - | ^
* ly_ctx_info() | ::ly_ctx_get_yanglib_data() | Clarification of what to expect as the output of the function and possibility to specify custom content ID.
* ly_ctx_get_module_set_id() | ::ly_ctx_get_change_count() | The functionality is the same but the exact meaning of the value was clarified.
* - | ::ly_ctx_unset_searchdir_last() | Extend the functionality of the ::ly_ctx_unset_searchdir() to make its use easier.
* ly_ctx_get_module_older() | - | Removed functionality.
* - | ::ly_ctx_get_module_implemented() | Supplement for ::ly_ctx_get_module()
* - | ::ly_ctx_get_module_latest() | ^
* - | ::ly_ctx_get_module_implemented_ns() | Supplement for ::ly_ctx_get_module_ns()
* - | ::ly_ctx_get_module_latest_ns() | ^
* - | ::ly_ctx_get_submodule_latest() | Supplement for ::ly_ctx_get_submodule()
* - | ::ly_ctx_get_submodule2_latest() | Supplement for ::ly_ctx_get_submodule2()
* ly_ctx_get_module_by_ns() | ::ly_ctx_get_module_ns () | Redesign the API - replace some of the parameters with standalone supplement functions.
* - | ::ly_ctx_reset_latests() | The new functionality of maintaining the latest module revision flag.
* ly_ctx_unset_searchdirs() | ::ly_ctx_unset_searchdir() | Simplify API and instead of index numbers, work with the values themselves.
* ly_ctx_set*() | ::ly_ctx_set_options() | API simplification.
* ly_ctx_unset*() | ::ly_ctx_unset_options() | ^
*
*
* @section transitionSchemas YANG Modules (Schema)
*
* The most significant change between libyang 1.x and 2.0 can be found in schema structures. The schema tree now has two
* different forms - parsed and compiled trees. While the parsed tree reflects the source of the YANG module, the compiled
* tree represents the final tree used to validate the instantiated data. Both formats can be found inside the covering
* ::lys_module structure. More about the new structures can be found at @ref howtoSchema page.
*
* This is an essential change allowing speed up and simplification of data validation, but requiring carefully determine
* which format is more suitable for the specific use case. As mentioned, the compiled trees are better for data validation
* and getting information about the intentioned structure of the schema with all the applied groupings, type modifications,
* augments, deviations, and any defined if-features. On the other hand, the parsed trees are useful for the schema format conversions since they
* provide the original structure of the modules. There is a number of new functions intended to work only with the
* parsed or the compiled tree. These functions are prefixed with `lysp_` and `lysp_` prefixes.
*
* Schema parser, as well as printer functions, are now extended to accept new
* [input / output handlers](@ref transitionGeneralInOut). The previous API working directly with inputs and outputs is
* preserved (or slightly changed), but the functions can be limited in the functionality of the new API. More information
* can be found at @ref howtoSchemaParsers and @ref howtoSchemaPrinters pages.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* - | ::lys_parse() | New generic schema parser API using [generic input handler](@ref howtoInput).
* - | ::lys_print_module() | New generic schema printer API using [generic output handler](@ref howtoOutput).
* - | ::lys_print_node() | ^
* - | ::lys_print_submodule() | ^
*
*
* The following table introduces other significant changes in the API functions connected with the schema.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lys_set_private() | - | Not needed, all ::lysc_node compatible structures have this pointer so it can be accessed directly.
* lys_is_disabled() | - | Make no sense since the nodes disabled by if-feature are not present in the compiled tree.
* lys_features_list() | - | Not needed, the list of features is available in the parsed tree of the module and submodule.
* lys_features_enable(), lys_features_enable_force() | ::lys_set_implemented() | Set of enabled features can be changed but it causes the whole context (all the modules) to recompile.
* lys_features_disable(), lys_features_disable_force() | - | ^
* lys_features_state() | - | Redesign of the features handling in the schema tree, the feature's status is newly directly visible as ::LYS_FENABLED flag (in parsed feature structure).
* - | ::lys_feature_value() | Simplified API to get feature's state only based on a feature name string.
* - | ::lysp_feature_next() | After redesigning features handling, this function helps to iterate over all features connected with the module.
* lys_iffeature_value() | ::lysc_iffeature_value() | Renamed, but note that after features handling redesign, the compiled if-feature structure to evaluate is only in ::lysp_feature.iffeatures_c.
* lys_iffeature_value() | - | Not needed since the if-feature statements are directly applied onto the compiled tree.
* lys_is_disabled() | - | ^
* lys_parent() | - | The compiled tree is more straightforward without the need to take care of nodes added via augments.
* lys_main_module() | - | The compiled tree does not include submodules, so there is always only the main module.
* lys_node_module() | - | ^
* lys_set_enabled() | - | It is not possible to change context this way (remove or disable modules).
* lys_set_disabled() | - | ^
* - | ::lys_find_child() | Helpers wrapper around ::lys_getnext().
* - | ::lys_getnext_ext() | Alternative to ::lys_getnext() allowing processing schema trees inside extension instances.
* - | ::lys_nodetype2str() | New functionality.
* lys_is_key() | ::lysc_is_key() | Renamed to connect with the compiled schema tree.
* - | ::lysc_is_userordered() | Added functionality to simplify the examination of generic compiled schema nodes.
* - | ::lysc_is_np_cont() | ^
* - | ::lysc_node_child() | ^
* - | ::lysc_node_actions() | ^
* - | ::lysc_node_notifs() | ^
* - | ::lysp_node_child() | Added functionality to simplify the examination of generic parsed schema nodes.
* - | ::lysp_node_actions() | ^
* - | ::lysp_node_notifs() | ^
* - | ::lysp_node_groupings() | ^
* - | ::lysp_node_typedefs() | ^
* - | ::lysc_tree_dfs_full() | Alternative DFS passing implementation to ::LYSC_TREE_DFS_BEGIN macro.
* - | ::lysc_module_dfs_full() | Supplement functionality to ::lysc_tree_dfs_full().
* lys_path(), lys_data_path() | ::lysc_path() | Redesigned functionality.
* lys_data_path_pattern() | - | Removed as useless
* lys_implemented_module() | ::ly_ctx_get_module_implemented() | Removed, the same result can be simply achieved using ::ly_ctx_get_module_implemented().
*
* There is a set of functions available to implement data type plugins for storing and manipulating data values in a more
* natural way to the specific data type. For example, IPv4 address type is defined as a string with a pattern, but it is
* more effective and usual to store and handle IPv4 as a 32-bit number.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:---------------------------------|:--------------------------------------------------------
* lys_getnext_union_type() | - | Removed after the type representation redesign.
* - | ::lyplg_type_identity_isderived()| Helper functions for base types.
* - | ::lyplg_type_parse_dec64() | ^
* - | ::lyplg_type_parse_int() | ^
* - | ::lyplg_type_parse_uint() | ^
* - | ::lyplg_type_validate_patterns() | ^
* - | ::lyplg_type_validate_range() | ^
* - | ::lyplg_type_get_prefix() | Helper functions for processing prefixes in data values.
* - | ::lyplg_type_prefix_data_new() | ^
* - | ::lyplg_type_prefix_data_dup() | ^
* - | ::lyplg_type_prefix_data_free() | ^
*
*
* YANG extensions are supported via [extension plugins API](@ref pluginsExtensions) allowing to implement specific extension
* and load its support into libyang as a shared module. libyang implements several extensions on its own (see
* @ref howtoPluginsExtensions), but even these internal implementations use the same API. The API and [mechanism of loading
* external plugins](@ref howtoPlugins) changed a lot in contrast to libyang 1.x. The plugins are now loaded automatically
* with creating the first libyang context. The only public function to handle external plugins is ::lyplg_add().
*
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lys_ext_complex_get_substmt()| lysc_ext_substmt() | Changed design of the extensions and the way how it's substatements are accessed.
* lys_ext_instance_presence() | lysc_ext_substmt() | ^
* lys_ext_instance_substmt() | lysc_ext_substmt() | ^
* ly_clean_plugins() | - | Manipulating external plugins (from plugins directories) is now automatically connected with creating (first) and destroying (last) libyang contexts.
* ly_get_loaded_plugins() | - | ^
* ly_load_plugins() | - | ^
* ly_register_exts() | ::lyplg_add() | Redesigned to a common function for any plugin type.
* ly_register_types() | ::lyplg_add() | ^
*
*
* @section transitionData Data Instances
*
* Conceptually, the data tree did not change as much as the schema tree. There is still a generic ::lyd_node structure that
* maps according to the schema node's nodetype to some of the other lyd_node_* structures. All the data nodes were extended
* by hashes to improve performance when searching and processing data trees. The hashes are used for example in the
* lyd_find_* functions.
*
* All the data nodes are also implicitly ordered following the order of the schema nodes. This is the
* reason to change the insertion function. Only the user-ordered lists and leaf-lists can be now placed relative to other
* instances of the same list/leaf-list. Otherwise, the data instance is always inserted/created at the correct place beside
* the right sibling nodes.
*
* For any functions that are available on inputs of different scale (node, subtree, all siblings, whole data tree),
* there are several variants of the specific function with suffix specifying what exactly the processed input will be
* (_single, _tree, _siblings, _all). This way the behavior is always clear in the code.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* %lyd_insert_after() | ::lyd_insert_after() | Changed meaning by limiting applicability only to user-ordered list and leaf-list instances.
* %lyd_insert_before() | ::lyd_insert_before() | ^
* lyd_schema_sort() | - | Not necessary since the nodes are sorted implicitly.
*
*
* Parsing data instances in XML format is newly done directly, without any interstep. Therefore, complete XML API
* (lyxml_*() functions) from libyang 1.x was removed.
*
* Parser's API was simplified to avoid variadic parameters. The functions are newly split to parsed data, notifications,
* RPCs and replies to the RPCs. Similarly to the schema parsers, also the new data parser API works with
* [input handlers](@ref transitionGeneralInOut). The data printer's API was also extended to use new
* [output handlers](@ref transitionGeneralInOut). However, part of the previous API working directly with inputs
* and outputs was preserved. More information about the data parser and printer can be found at
* @ref howtoDataParsers and @ref howtoDataPrinters pages.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* - | ::lyd_parse_data() | Redesigned data tree parser.
* lyd_parse_xml() | - | XML tree format was removed.
* lyd_parse_fd() | ::lyd_parse_data_fd() | Renamed and limited to data trees only.
* lyd_parse_mem() | ::lyd_parse_data_mem() | ^
* lyd_parse_path() | ::lyd_parse_data_path() | ^
* - | ::lyd_parse_ext_data() | Separated function for parsing data trees matching a schema tree of the given extension instance.
* - | ::lyd_parse_op() | Separated function for parsing RPCs, actions, replies, and notifications.
* - | ::lyd_parse_ext_op() | Separated function for parsing RPCs, actions, replies, and notifications of the given extension instance.
* - | ::lyd_print_all() | New API accepting ::ly_out.
* - | ::lyd_print_tree() | ^
*
*
* Data validation is still done as part of the parser's process. The standalone functionality is available to check the
* result of data manipulation with the values of the terminal nodes or with the structure of the data tree. In contrast to
* libyang 1.x, adding the default nodes was made available as a standalone function to simplify the data manipulation
* process before the final validation.
*
* Many validation flags were removed because they became obsolete (LYD_OPT_DESTRUCT, LYD_OPT_WHENAUTODEL,
* LYD_OPT_NOEXTDEPS, LYD_OPT_DATA_NO_YANGLIB, LYD_OPT_VAL_DIFF) or we consider them redundant (LYD_OPT_OBSOLETE,
* LYD_OPT_NOSIBLINGS, LYD_OPT_DATA_ADD_YANGLIB). As for LYD_OPT_TRUSTED, this option was mostly replaced with
* ::LYD_PARSE_ONLY because both skip validation but with the significant difference that LYD_OPT_TRUSTED also sets
* the data node flags to be considered validated. The current option ::LYD_PARSE_ONLY does not do this because
* there is now much better support for working with non-validated data trees. Also, in case an invalid tree was marked
* as validated, it could lead to some undesired behavior, which is now avoided.
*
* Worth mentioning is a difference in the LYB format, which now also stores its validation flags. So, in case
* a validated data tree is stored, it is also loaded as validated.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lyd_validate() | ::lyd_validate_all(), ::lyd_validate_op() | Redesigned functionality.
* lyd_validate_modules() | ::lyd_validate_module() | ^
* lyd_validate_value(), lyd_value_type() | ::lyd_value_validate() | Redesigned functionality.
* - | ::lyd_new_implicit_all() | New in API to explicitly add default nodes, previously done only as part of the validation process.
* - | ::lyd_new_implicit_module() | Supplement functionality to ::lyd_new_implicit_all().
* - | ::lyd_new_implicit_tree() | ^
*
*
* The `diff` functionality was completely redesigned. Instead of the array of operations to transform one tree into another,
* the difference between two data trees has newly a form of the annotated data tree describing the differences. A number of
* functions to use the diff tree was added into API. To simply compare just nodes, there are the `compare` functions.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lyd_diff() | ::lyd_diff_tree() | Redesigned functionality.
* - | ::lyd_diff_siblings() | Supplement functionality to ::lyd_diff_tree().
* - | ::lyd_diff_apply_all() | ^
* - | ::lyd_diff_apply_module() | ^
* - | ::lyd_diff_merge_all() | ^
* - | ::lyd_diff_merge_module() | ^
* - | ::lyd_diff_merge_tree() | ^
* - | ::lyd_diff_reverse_all() | ^
* lyd_free_diff() | - | Removed.
* lyd_free_val_diff() | - | Removed.
* - | ::lyd_compare_single() | Added functionality.
* - | ::lyd_compare_meta() | Supplement functionality to ::lyd_compare_single()
* - | ::lyd_compare_siblings() | ^
*
*
* For now, the functionality of moving data between two different contexts is not implemented. If you have a real use case
* for this functionality, let us know.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lyd_dup() | ::lyd_dup_single() | Redesigned functionality.
* lyd_dup_withsiblings() | ::lyd_dup_siblings() | ^
* - | ::lyd_dup_meta_single() | Supplement functionality to ::lyd_dup_single().
* lyd_dup_to_ctx() | - | Transferring data from one context to another is not supported.
* lyd_merge() | ::lyd_merge_tree() | Renamed.
* - | ::lyd_merge_siblings() | Supplement functionality to ::lyd_merge_tree()
* lyd_merge_to_ctx() | - | Transferring data from one context to another is not supported.
*
*
* There is a significant change in the value structure in terminal nodes. Thanks to the changes in the schema tree,
* it is now much more straightforward to get the type of the value and work with the alternative representation of the value
* fitting better to its type. There is also a new API for the type plugins (see @ref howtoPluginsTypes). Even the base YANG
* data types are now implemented using this API and can be taken as examples for implementing derived data types.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lyd_new(), lyd_new_output() | ::lyd_new_inner(), ::lyd_new_list(), ::lyd_new_list2() | Redesigned functionality to better fit new lyd_node structures, creating RPC's output data is now done via a flag parameter of the functions.
* lyd_new_leaf(), lyd_new_output_leaf() | ::lyd_new_term() | ^
* lyd_new_anydata(), lyd_new_output_anydata() | ::lyd_new_any() | ^
* lyd_new_yangdata() | ::lyd_new_ext_inner(), ::lyd_new_ext_list(), ::lyd_new_ext_term(), ::lyd_new_ext_any() | Additional functionality to lyd_new_* functions to cover top-level nodes in extension instances.
* lyd_insert_attr() | ::lyd_new_meta() | Unify naming used in other functions with the similar functionality.
* - | ::lyd_new_attr() | Added functionality to store the data (temporarily) not connected with schema definitions.
* - | ::lyd_new_attr2() | ^
* - | ::lyd_new_opaq() | ^
* - | ::lyd_new_opaq2() | ^
* - | ::lyd_new_path2() | Supplement functionality to ::lyd_new_path().
* - | ::lyd_new_ext_path() | Supplement functionality to ::lyd_new_path() covering data defined in extension instances.
* lyd_insert() | ::lyd_insert_child() | Renamed to better distinguish from ::lyd_insert_sibling().
* lyd_change_leaf() | ::lyd_change_term() | Align naming with changed names of data structures.
* - | ::lyd_change_meta() | Transferred functionality of ::lyd_change_term() to metadata.
* - | ::lyd_any_copy_value() | Added functionality.
* lyd_free() | ::lyd_free_tree() | Renamed.
* lyd_free_withsiblings() | ::lyd_free_all() | ^
* - | ::lyd_free_siblings() | Supplement functionality to ::lyd_free_siblings().
* lyd_free_attr() | ::lyd_free_attr_single() | Renamed.
* - | ::lyd_free_attr_siblings() | Supplement functionality to ::lyd_free_attr_single().
* - | ::lyd_free_meta_single() | Added functionality.
* - | ::lyd_free_meta_siblings() | ^
* lyd_unlink() | ::lyd_unlink_tree() | Renamed.
*
*
* Here is the table of other changes in data API.
*
* libyang 1.x | libyang 2.0 | Notes
* :----------------------------|:--------------------------------|:---------------------------------------------------------
* lyd_find_instance() | - | Removed.
* lyd_find_sibling() | - | Removed, functionality can be replaced by ::lyd_find_sibling_val().
* lyd_find_sibling_set() | - | ^
* - | ::lyd_find_sibling_first() | Alternative function to ::lyd_find_sibling_val().
* - | ::lyd_find_meta() | New functionality.
* lyd_wd_default() | ::lyd_is_default() | Renamed to unlink from with-default capability.
* - | ::lyd_parent() | New wrapper to get generic ::lyd_node pointer of the parent.
* - | ::lyd_child(), ::lyd_child_no_keys() | New wrapper to cover all children possibilities hidden behind a generic ::lyd_node structure.
* - | ::lyd_owner_module() | Added functionality.
* - | ::lyd_value_compare() | Added Functionality.
* - | ::lyd_target() | Added functionality for the instance-identifier representation.
* lyd_node_module() | - | Not necessary since the connection with the compiled modules is much more straightforward.
* lyd_leaf_type() | - | Not necessary since the real type information is much more clear from the new ::lyd_value.
* lyd_dec64_to_double() | - | Removed as useless.
* lyd_node_should_print() | - | ^
*/