YANG Schema Comparison
CESNET
mvasko@cesnet.cz
Ionio Systems
per.ietf@ionio.se
Cisco Systems, Inc.
rwilton@cisco.com
This document specifies an algorithm with two input variants for
comparing revisions of a YANG schema to determine the scope of
changes and produce a list of the changes between the revisions.
The output of the algorithm can be used to help select an
appropriate YANG semantic version number for a new YANG Module
revision. It also specifies a YANG module for YANG-structured
output of these algorithms, that can be easily consumed in a
machine-readable way.
Introduction
This document defines a common algorithm for comparing two
revisions of a YANG schema. As input, there can be two types of
YANG schema representations: single locally resolved YANG modules
or fully resolved set of YANG modules (on-the-wire schema). The
algorithm output for each of these representations serves a
different purpose. It can help YANG authors with assigning the
correct semantic version of a module based on
or
tools processing YANG instance data can use it to learn about the
exact data changes, respectively.
The algorithm operates in a straightforward way traversing all the
statements and their substatements in both the old and new module
representations collecting identified changes. These are then
reported in a concise output with information about the overall
backwards compatibility between the two modules. Exact output
format is out of scope for this document but Appendix A includes an
example of a YANG module whose YANG data can represent all the
possible changes and so a complete output of this algorithm.
Every change is classified as editorial, backwards-compatible, or
non-backwards-compatible. This conformance is decided based on
rules found in other documents, specifically
,
,
and .
For older YANG 1.0 modules, the rules in
apply instead.
Terminology and ConventionsThe key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP 14
when, and only when, they
appear in all capitals, as shown here.
This document makes use of the following terminology introduced in
the YANG 1.1 Data Modeling Language :
moduleschema nodedata nodedata definition statement
In addition, this document uses the following terminology:
locally resolved module: A parsed YANG module with all its
submodules and local references resolved.fully resolved schema: A locally resolved module with all the
imported references resolved as well and with non data
definition statements removed.Schema representations
The YANG language defines several statements that act as syntactic
abstraction and need to be processed before a YANG module can be
used for handling YANG instance data. For example, a “uses”
statement is replaced by all the substatements of a referenced
“grouping” statement or a “typedef” statement can be linked to
other “type” statements. The referenced statements can be local
(defined in the same module, or included submodule) but also
foreign (defined in another imported module).
Locally resolved module (single module)
This representation of a YANG module includes all submodules of the
main module but resolves only statements that reference other
statements found in the same module. No references to imported
modules (that are using an imported prefix) are resolved.
For example, any changes of a referenced “typedef” or “grouping”
defined in an imported module would not affect the locally resolved
module and are out of scope for this representation.
All the rules for classifying individual statement changes
mentioned in
apply to this module representation.
Deviation
Regardless of whether the “deviation” target node is local
in the same module or in an imported module, it is never
resolved and applied. Instead, the “deviation” statement
with all its substatements is kept in the locally resolved
module so that it can be considered in the schema
comparison algorithm.
Refine
The “refine” statement is processed differently based on
whether the affected “grouping” is defined in an imported
module or the local YANG module. In the former case, when
the relevant grouping is imported, the “refine” is not
resolved and kept in the module. And then examined in the
comparison algorithm, similarly to the “deviation” statement.
However, all the “refine” statements targeting a local
“grouping” are applied on the nodes of the grouping when
the “uses” is resolved. After processing the “refine”
statements with all its substatements, they are effectively
removed from the locally resolved module to avoid reporting
changes of any “refine” statements twice.
Augment
All the “augment” statements are processed similarly to
“refine” statements. Meaning that augments of imported
groupings are not resolved and compared directly while
augments of local groupings are applied and then removed
from the module.
Fully resolved schema (set of modules)
The fully resolved schema representation consists of one or
more YANG modules. Each of these is fully resolved according to
the rules of the YANG language meaning that every referenced
statement, including to other imported modules, is resolved,
unlike locally resolved modules. The result is one large tree
with schema nodes of all the YANG modules. The comparison
algorithm MAY then choose to compare top-level schema node
subtrees belonging only to a single YANG module.
Next, all the statements used only for syntactic abstraction
that do not affect YANG instance data are removed. Note that
the “description” or “units” statements are kept because they
may influence the data. Also, “error-app-tag” and
“error-message” statements remain in the fully resolved schema
for applications to learn that the generated error information
has changed.
The steps taken when fully resolving a module include:
All submodules of a single module are merged to create one
large YANG module.
"Import" statements are resolved by finding the referenced
YANG modules and making their contents available.
"Uses" statements are replaced by the referenced
"groupings" and the YANG nodes they define.
Any “when” statement of the “uses” is moved down to all the
direct descendant schema nodes of the “grouping”.
Types referencing any "typedef" statements are replaced
with the actual type details.
Augments are resolved by placing the included YANG nodes in
their targets.
Any “when” statement of the “augment” is moved down to all
the direct descendant schema nodes of the “augment”.
"Deviation" and "refine" statements are applied by changing
the appropriate schema nodes.
All the "if-feature" statements are evaluated based on the
enabled "features" of implemented YANG modules and the
disabled schema nodes are removed.
All the extension-instances have a matching “extension”
defintion.
After the resolution, the following statements are completely
removed with their substatements:
organization
contact
reference
import
include
revision
typedef
grouping
augment
deviation
feature
if-feature
refine
extension
Also, these schema nodes are removed but replaced with their
schema node substatements:
choice
case
The term “schema” was chosen instead of “module” on purpose
because when statements are imported from external modules, the
resulting schema then includes statements from several YANG
modules. But the fully resolved schema representation of a
module always includes only the top-level schema node trees of
that module.
Only a subset of the module update rules in
apply for
the fully resolved schema. Specifically, the rules for removed
statements cannot be applied but other present statements are
processed normally.
How the concrete set of YANG modules of a fully resolved schema
is described is out of scope of this document. But suitable
existing structures include YANG data of “ietf-yang-library” from
or
“ietf-yang-package-instance” in
.
Choosing a schema representation
Selecting a suitable schema representation for the comparison
algorithm depends on the desired purpose. But for a complete
set of changes, both the representations should be compared and
their output merged to get the combined output of the two
comparisons.
YANG module authors will primarily be interested in the locally
resolved module representation. Using it for the comparison
algorithm will yield all the changes that occurred in the
specific YANG module only while ignoring any possible changes
in imported modules. This information can then directly be used
to decide the correct semantic version of the new revision of
this module. The rules for selecting versions are defined in
.
Any YANG-based application handling YANG instance data always
uses the fully resolved schema representation. So, when running
the schema comparison algorithm with the intent of learning the
changes in the corresponding valid YANG instance data of the
module, this representation should be used. With some
additional information, the output of this comparison can then
also be used to transform valid data of the old schema revision
to data valid for the new schema revision. All these tools and
applications are typically clients or servers of YANG-driven
protocols, e.g. NETCONF, RESTCONF, or gRPC.
Examples
To illustrate the different output of the comparison
algorithm each schema representation can generate for the
same YANG module changes, following are a few examples.
When a “typedef” or “grouping” name changes, the algorithm
for locally resolved module will detect the change and
report it as non-backwards-compatible. This is useful
especially when importing such a module to learn that any
references to the original statements will no longer be
valid. However, if using the fully resolved schema, this
difference will not be detected at all since it does not
affect YANG instance data corresponding to this module.
Another specific use-case is when a module with “uses” that
referenced an external “grouping” replaces that “uses” node
directly with schema nodes in the “grouping” effectively
resolving the “uses” similarly to a YANG module parser.
Such a change is non-backwards-compatible based on the YANG
1.1 updating rules and reported that way when using a
locally resolved module. But the fully resolved schemas
will be completely the same before and after the change so
the comparison algorithm will not generate any changes and
report full compatibility of the old and the new modules
with their instance data.
Comparison algorithm
This algorithm is defined for individual locally resolved
modules and fully resolved schemas. All the statements are
compared with their content, recursively, in the old revision
and the new revision of the module or schema. Depth-first
search order for the statement traversal SHOULD be used.
The non data definition statements are considered modified when
their content is changed or any of their substatements are
changed. If a statement is present in the old revision and
missing in the new revision, it is considered removed.
Conversely, if missing in the old revision but present in the
new revision, it is considered added.
Data definition statements are compared similarly except that a
change in a descendant data definition statement is not
considered a change of the parent data definition statement but
a separate change instead.
Only statements with any changes are reported and included in
the comparison algorithm output.
Module identification
When generating the comparison output of two modules,
unique identification of these modules SHOULD be included.
For both the old and the new revision of the base module,
its name, revision, list of submodules, and a leaf-list of
enabled features is included. For the fully resolved
schema, the same information is also reported for all the
imported YANG modules, recursively. This ensures that if
any other output is produced with a different set of
changes for two fully resolved schemas, their
identification information must also differ.
Change conformance
Every change is classified as editorial,
backwards-compatible, or non-backwards-compatible. The
classification is based on Section 11 of
which mentions
most of the possible changes between two revisions of a
YANG 1.1 module and Section 3.1 of
adds more details about the exact conformance of statements
with various "status" statement values. Finally,
defines what classifies as an editorial change.
General non-normative explanation of change conformance
classification can be found in
.
Deviations, Refines, and Augments
All the statement change conformance follows the
general rules above if these statements are present in
the schema representation, see
.
But this clarification is added to make certain that
the rules are interpreted correctly.
Since “deviation” and “refine” statements are not among
the allowed statements that can be changed when
updating a module in Section 11 of
, any
non-editorial change of these statements or their
substatements is treated as non-backwards-compatible.
But since “augment” statements can only add schema
nodes, these can be processed and compared normally.
So, for example, even if removing the “mandatory”
statement is considered backwards-compatible, a new
“deviation” removing the “mandatory” statement from its
target node is considered a non-backwards-compatible
change. Similarly a “refine” of the “description” of a
node is classified as non-backward-compatible change.
However, a change in the “description” of a “deviation”
statement is treated as a standard “description” change
because it describes the “deviation” statement itself
and does not affect the deviation target node.
Conformance extensions
There are cases when it may be impossible for tooling
to accurately determine the conformance of a change but
a default conformance is always assumed for every
statement. The affected ambiguous statements with their
default conformances are:
pattern - NBC
when - NBC
must - NBC
description - Editorial
reference - Editorial
presence - Editorial
extension instance - BC
Normally, any modification of these statements is
reported with the default change conformance. However,
if the author of the new revision of a YANG module
determines that the change of one of the aforementioned
statements has a different conformance based on the
compatibility rules for the specific statement, they
can decide to use the special extension instances to
signify this fact. These are:
ed-change-at SEMVER
bc-change-at SEMVER
nbc-change-at SEMVER
They determine the conformance of the change of the
marked statement to be editorial, backwards-compatible,
or non-backwards-compatible, respectively. The argument
is a semantic version of the YANG module revision that
introduced the specific change and these extension
instances are sticky, meaning they remain in the module
even in its later revisions. Also, a YANG statement can
have multiple conformance extension statements. For
example, when a pattern changes in multiple versions of
a module, each change can be marked with an extension
to explicitly state the conformance of the change.
Algorithm variants support
Tools implementing schema comparison SHOULD support
comparing locally resolved modules, fully resolved schemas,
and both representations together. In case the comparison
generates YANG data for the
"ietf-yang-schema-comparison-output" YANG module, simple
XPath filters can be used to select any subset of changes.
Data definition statements are present in both the locally
resolved module and fully resolved schema. So if both
representations are compared normally, there would be
duplicate changes reported in the algorithm output. These
duplicate changes MUST be avoided and filtered out.
Schema Comparison YANG Module
YANG module with extensions for fine-tuning the classification
of differences between two revisions of YANG schemas.
WG Web: https://datatracker.ietf.org/wg/netmod
Author: Michal Vaško
Author: Rob Wilton
Author: Per Andersson
";
description
"This YANG 1.1 module contains extensions to support comparison
between different versions of YANG schemas.
Copyright (c) 2026 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Revised
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document
are to be interpreted as described in BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
// RFC Ed.: replace XXXX (inc above) with actual RFC number and
// remove this note.
revision 2026-09-02 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Schema Comparison";
}
extension ed-change-at {
argument semver;
description
"Marks statements in a new revision of a module
that introduces an editorial change of the statement.
The argument marks the most recent version of the
module where the statement has been changed.
Can only be a substatement of 'pattern', 'when',
'must', 'description', 'reference', 'presence', or
extension instance statements.";
reference
"RFC 7950: The YANG 1.1 Data Modeling Language, section 11;
RFC 6020: YANG - A Data Modeling Language for the Network
Configuration Protocol (NETCONF), section 10";
}
extension bc-change-at {
argument semver;
description
"Marks statements in a new revision of a module
that introduces a backwards-compatible change of
the statement.
The argument marks the most recent version of the
module where the statement has been changed.
Can only be a substatement of 'pattern', 'when',
'must', 'description', 'reference', 'presence', or
extension instance statements.";
reference
"RFC 7950: The YANG 1.1 Data Modeling Language, section 11;
RFC 6020: YANG - A Data Modeling Language for the Network
Configuration Protocol (NETCONF), section 10";
}
extension nbc-change-at {
argument semver;
description
"Marks statements in a new revision of a module
that introduces a non-backwards-compatible change of
the statement.
The argument marks the most recent version of the
module where the statement has been changed.
Can only be a substatement of 'pattern', 'when',
'must', 'description', 'reference', 'presence', or
extension instance statements.";
reference
"RFC 7950: The YANG 1.1 Data Modeling Language, section 11;
RFC 6020: YANG - A Data Modeling Language for the Network
Configuration Protocol (NETCONF), section 10";
}
}
]]>ContributorsThis document grew out of the YANG module versioning design team that
was formed after IETF 101. The following individuals are (or have been) members
of the design team and have contributed on the YANG versioning project:
Balazs Lengyel
Benoit Claise
Bo Wu
Ebben Aries
Jason Sterne
Joe Clarke
Juergen Schoenwaelder
Mahesh Jethanandani
Michael Wang
Qin Wu
Reshad Rahman
Rob Wilton
Jan Lindblad
Per Andersson
The idea of a tooling-based comparison of YANG module revisions was
first described in .
This document builds on those initial ideas.Security Considerations
This section is modeled after the template described in Section 3.7.1
of .
The YANG modules specified in this document define extensions
("ietf-yang-schema-comparison") and a schema for data
("ietf-yang-schema-comparison-output") that are designed to be used
by offline tooling to generate output describing the differences
between two supplied YANG modules.
The YANG module specified in this document MAY be accessed via
network management protocols such as NETCONF
or RESTCONF . The
lowest NETCONF layer is the secure transport layer, and the
mandatory-to-implement secure transport is Secure Shell (SSH)
. The lowest RESTCONF layer is HTTPS, and
the mandatory-to-implement secure transport is TLS
.
The Network Configuration Access Control Model (NACM)
provides the means to restrict access for
particular NETCONF or RESTCONF users to a preconfigured subset of
all available NETCONF or RESTCONF protocol operations and content.
When the module is used by offline tooling, there are no security
considerations, since the user has full access to all YANG modules
being used.
The "schema-comparison" structure defined in the
"ietf-yang-schema-comparison-output" module contains all the
groupings reflecting the changes between YANG modules. If instances
of this structure are generated or published by online tooling,
care needs to be taken so that information about non-public YANG
modules is not inadvertently disclosed.
Since the module does not define any RPCs, actions, or
notifications, the security considerations for such statements are
not provided here.
IANA ConsiderationsThe "IETF XML" RegistryThis document registers two URIs in the "ns" subregistry of
the IETF XML Registry
maintained at .
Following the format defined in ,
the following registrations are requested:
URI: urn:ietf:params:xml:ns:yang:ietf-yang-schema-comparison
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-yang-schema-comparison-output
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
The "YANG Module Names" RegistryThis document registers two YANG modules in the YANG Module Names
registry maintained at
.
Following the format defined in , the following
registrations are requested:
Name: ietf-yang-schema-comparison
XML Namespace: urn:ietf:params:xml:ns:yang:ietf-yang-schema-comparison
Prefix: schema-cmp
Reference: RFC XXXX
Name: ietf-yang-schema-comparison-output
XML Namespace: urn:ietf:params:xml:ns:yang:ietf-yang-schema-comparison-output
Prefix: schema-cmp-out
Reference: RFC XXXX
Schema Comparison Algorithm Output YANG Module
This YANG module defines the specific output of the schema
comparison algorithm, supporting comparison of the locally
resolved module, fully resolved schema, or both. The
"ietf-yang-schema-comparison-output" YANG module imports
definitions from the "ietf-yang-types" module defined in
, the "ietf-yang-library" module defined in
, and the "ietf-yang-structure-ext" module
defined in .
Generating schema comparison data in the form of YANG instance data
compliant with this YANG module is optional but makes it easier for
further automatic processing by tools and also allows for simple
filtering of the data.
Non data definition statements are uniquely identified with their
YANG identifier and data definition statements with their absolute
schema node-ids. For every change, the changed statement and the
parent of the changed statement are included. While redundant in
many cases, it allows the algorithm to uniquely report changes in
nested statements, e.g. an extension instance change in the type of
a leaf statement. Also, all the unchanged substatements with their
value or content are included for every changed statement, for both
the older and the newer revision of the YANG module, if applicable.
This ensures that the output includes all the possibly required
information without relying on learning it from the YANG modules
themselves.
WG Web: https://datatracker.ietf.org/wg/netmod
Author: Michal Vaško
Author: Rob Wilton
Author: Per Andersson
";
description
"This YANG 1.1 module contains definitions of output of comparison
between different versions of YANG schemas. The base schema nodes
describe changes in a compiled YANG module with all of its
included submodules and imported modules. The rest of the schema
nodes are optional and describe changes in all the statements of a
single YANG module.
Copyright (c) 2026 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Revised
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document
are to be interpreted as described in BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
// RFC Ed.: replace XXXX (inc above) with actual RFC number and
// remove this note.
revision 2026-09-02 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Schema Comparison";
}
typedef schema-node-path {
type string;
description
"Node schema path (node-id). A generic type is used to not enforce
their evaluation or validation in this context.";
}
typedef schema-stmt-path {
type string;
description
"Path to a statement. Any non data node parents are encoded
specially.";
}
typedef stmt-type {
type enumeration {
enum base {
description
"YANG statement 'base'.";
}
enum bit {
description
"YANG statement 'bit'.";
}
enum config {
description
"YANG statement 'config'.";
}
enum contact {
description
"YANG statement 'contact'.";
}
enum default {
description
"YANG statement 'default'.";
}
enum description {
description
"YANG statement 'description'.";
}
enum enum {
description
"YANG statement 'enum'.";
}
enum error-app-tag {
description
"YANG statement 'error-app-tag'.";
}
enum error-message {
description
"YANG statement 'error-message'.";
}
enum extension {
description
"YANG statement 'extension'.";
}
enum extension-instance {
description
"Any extension instance YANG statement.";
}
enum feature {
description
"YANG statement 'feature'.";
}
enum fraction-digits {
description
"YANG statement 'fraction-digits'.";
}
enum identity {
description
"YANG statement 'identity'.";
}
enum if-feature {
description
"YANG statement 'if-feature'.";
}
enum import {
description
"YANG statement 'import'.";
}
enum include {
description
"YANG statement 'include'.";
}
enum length {
description
"YANG statement 'length'.";
}
enum mandatory {
description
"YANG statement 'mandatory'.";
}
enum max-elements {
description
"YANG statement 'max-elements'.";
}
enum min-elements {
description
"YANG statement 'min-elements'.";
}
enum must {
description
"YANG statement 'must'.";
}
enum node {
description
"YANG statement 'container', 'leaf', 'leaf-list', 'list',
'anydata', 'anyxml', 'rpc', 'action', or 'notification'.
If the locally resolved module is also compared, it can
additionally be 'choice', 'case', 'input', 'output',
'uses', 'augment', or 'grouping'.";
}
enum ordered-by {
description
"YANG statement 'ordered-by'.";
}
enum organization {
description
"YANG statement 'organization'.";
}
enum path {
description
"YANG statement 'path'.";
}
enum pattern {
description
"YANG statement 'pattern'.";
}
enum prefix {
description
"YANG statement 'prefix'.";
}
enum presence {
description
"YANG statement 'presence'.";
}
enum range {
description
"YANG statement 'range'.";
}
enum reference {
description
"YANG statement 'reference'.";
}
enum refine {
description
"YANG statement 'refine'.";
}
enum require-instance {
description
"YANG statement 'require-instance'.";
}
enum revision-date {
description
"YANG statement 'revision-date'.";
}
enum status {
description
"YANG statement 'status'.";
}
enum type {
description
"YANG statement 'type'.";
}
enum typedef {
description
"YANG statement 'typedef'.";
}
enum units {
description
"YANG statement 'units'.";
}
enum unique {
description
"YANG statement 'unique'.";
}
enum when {
description
"YANG statement 'when'.";
}
enum yang-version {
description
"YANG statement 'yang-version'.";
}
}
description
"Type of the statement that a change affects.";
}
typedef revision-or-empty {
type union {
type empty;
type yanglib:revision-identifier;
}
description
"Module or submodule revision. If it has none, an empty value is used.";
}
grouping if-feature-stmts {
description
"Describes changes of all the if-features on a statement.";
leaf-list if-feature {
type string;
description
"Value of an if-feature statement.";
}
}
grouping ext-instance-stmt {
description
"Describes changes of an extension instance.";
leaf module {
type yang:yang-identifier;
mandatory true;
description
"Module with the extension definition of an extension
instance.";
}
leaf name {
type yang:yang-identifier;
mandatory true;
description
"Name of the extension definition of an extension instance.";
}
leaf argument {
type string;
description
"Argument used of an extension definition.";
}
anydata substatements {
description
"Any substatements of the extension instance.";
}
}
grouping ext-instance-stmts {
description
"Describes changes of all the extension instances.";
list ext-instance {
description
"List of extension-instance substatements.";
uses ext-instance-stmt;
}
}
grouping status-stmt {
description
"Describes a status statement change.";
leaf status {
type enumeration {
enum current {
description
"Current effective status of a statement.";
}
enum deprecated {
description
"Deprecated effective status of a statement.";
}
enum obsolete {
description
"Obsolete effective status of a statement.";
}
}
mandatory true;
description
"Status substatement value.";
}
}
grouping must-stmts {
description
"Describes changes of all the must statements of a specific parent
statement.";
list must {
description
"List of must substatements.";
leaf condition {
type string;
description
"Condition substatement value.";
}
uses restriction-substmts;
}
}
grouping when-stmts {
description
"Describes changes of all the when statements of a specific parent
statement.";
list when {
description
"List of when substatements.";
leaf condition {
type string;
description
"Condition substatement value.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses status-stmt;
uses ext-instance-stmts;
}
}
grouping restriction-substmts {
description
"Common substatements shared by all restriction statements.";
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
leaf error-message {
type string;
description
"Error-message substatement value.";
}
leaf error-app-tag {
type string;
description
"Error-app-tag substatement value.";
}
uses ext-instance-stmts;
}
grouping type-substmts {
description
"Describes a type statement change.";
leaf base-type {
type enumeration {
enum int8 {
description
"YANG built-in type 'int8'.";
}
enum int16 {
description
"YANG built-in type 'int16'.";
}
enum int32 {
description
"YANG built-in type 'int32'.";
}
enum int64 {
description
"YANG built-in type 'int64'.";
}
enum uint8 {
description
"YANG built-in type 'uint8'.";
}
enum uint16 {
description
"YANG built-in type 'uint16'.";
}
enum uint32 {
description
"YANG built-in type 'uint32'.";
}
enum uint64 {
description
"YANG built-in type 'uint64'.";
}
enum decimal64 {
description
"YANG built-in type 'decimal64'.";
}
enum string {
description
"YANG built-in type 'string'.";
}
enum boolean {
description
"YANG built-in type 'boolean'.";
}
enum enumeration {
description
"YANG built-in type 'enumeration'.";
}
enum bits {
description
"YANG built-in type 'bits'.";
}
enum binary {
description
"YANG built-in type 'binary'.";
}
enum leafref {
description
"YANG built-in type 'leafref'.";
}
enum identityref {
description
"YANG built-in type 'identityref'.";
}
enum empty {
description
"YANG built-in type 'empty'.";
}
enum union {
description
"YANG built-in type 'union'.";
}
enum instance-identifier {
description
"YANG built-in type 'instance-identifier'.";
}
}
description
"Type substatement value.";
}
container range {
description
"Range statement substatements.";
list interval {
description
"Intervals of a range statement.";
leaf min {
type int64;
description
"Lower boundary of an interval of a range statement.";
}
leaf max {
type int64;
description
"Upper boundary of an interval of a range statement.";
}
}
uses restriction-substmts;
}
container length {
description
"Length statement substatements.";
list interval {
description
"Intervals of a length statement.";
leaf min {
type uint64;
description
"Lower boundary of an interval of a length statement.";
}
leaf max {
type uint64;
description
"Upper boundary of an interval of a length statement.";
}
}
uses restriction-substmts;
}
leaf fraction-digits {
type uint8;
description
"Fraction-digits substatement value.";
}
list pattern {
description
"List of pattern statements.";
leaf expression {
type string;
description
"Pattern substatement value.";
}
leaf inverted {
type boolean;
description
"A value of true indicates that the pattern's 'modifier'
substatement is 'invert-match'.";
reference
"RFC 7950 Section 9.4.6";
}
uses restriction-substmts;
}
list enum {
key "name";
ordered-by user;
description
"List of enum statements. Keeps the same order of the statements
as in the module.";
leaf name {
type yang:yang-identifier;
description
"Enum statement name.";
}
uses if-feature-stmts {
description
"Populated only for locally resolved module.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
leaf value {
type int32;
description
"Value substatement value.";
}
uses status-stmt;
uses ext-instance-stmts;
}
list bit {
key "name";
ordered-by user;
description
"List of bit statements. Keeps the same order of the statements
as in the module.";
leaf name {
type yang:yang-identifier;
description
"Bit statement name.";
}
uses if-feature-stmts {
description
"Populated only for locally resolved module.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
leaf position {
type uint32;
description
"Position substatement value.";
}
uses status-stmt;
uses ext-instance-stmts;
}
leaf path {
type string;
description
"Path substatement value.";
}
leaf require-instance {
type boolean;
description
"Require-instance substatement value.";
}
leaf-list base {
type yang:yang-identifier;
description
"List of base substatement values.";
}
uses ext-instance-stmts;
}
grouping type-local-substmts {
description
"Describes a locally resolved module type statement change.";
leaf name {
type yang:yang-identifier;
description
"Type argument substatement value.";
}
container range {
description
"Range statement substatements.";
leaf restriction {
type string;
description
"Range argument substatement value.";
}
uses restriction-substmts;
}
container length {
description
"Length statement substatements.";
leaf restriction {
type string;
description
"Length argument substatement value.";
}
uses restriction-substmts;
}
leaf fraction-digits {
type uint8;
description
"Fraction-digits substatement value.";
}
list pattern {
description
"List of pattern statements.";
leaf expression {
type string;
description
"Pattern substatement value.";
}
leaf inverted {
type empty;
description
"Presence indicates that the pattern's 'modifier'
substatement is 'invert-match'.";
reference
"RFC 7950 Section 9.4.6";
}
uses restriction-substmts;
}
list enum {
key "name";
ordered-by user;
description
"List of enum statements. Keeps the same order of the statements
as in the module.";
leaf name {
type yang:yang-identifier;
description
"Enum statement name.";
}
uses if-feature-stmts;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
leaf value {
type int32;
description
"Value substatement value.";
}
uses status-stmt;
uses ext-instance-stmts;
}
list bit {
key "name";
ordered-by user;
description
"List of bit statements. Keeps the same order of the statements
as in the module.";
leaf name {
type yang:yang-identifier;
description
"Bit statement name.";
}
uses if-feature-stmts;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
leaf position {
type uint32;
description
"Position substatement value.";
}
uses status-stmt;
uses ext-instance-stmts;
}
leaf path {
type string;
description
"Path substatement value.";
}
leaf require-instance {
type boolean;
description
"Require-instance substatement value.";
}
leaf-list base {
type yang:yang-identifier;
description
"List of base substatement values.";
}
uses ext-instance-stmts;
}
grouping refine-node-substmts {
description
"All substatements of a data-definition node that can be changed
by a refine statement.";
uses must-stmts;
leaf-list default {
type string;
description
"List of default substatement values.";
}
leaf config {
type boolean;
description
"Config substatement value.";
}
leaf mandatory {
type boolean;
description
"Mandatory substatement value.";
}
leaf min-elements {
type uint32;
description
"Min-elements substatement value.";
}
leaf max-elements {
type uint32;
description
"Max-elements substatement value.";
}
}
grouping node-substmts {
description
"All substatements of a data-definition node.";
uses if-feature-stmts {
when "../../locally-resolved";
}
uses when-stmts;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses status-stmt;
uses refine-node-substmts;
leaf-list key {
type yang:yang-identifier;
description
"Leaf-list of nodes referenced by a key statement.";
}
leaf ordered-by {
type enumeration {
enum system {
description
"System-ordered list or leaf-list of items.";
}
enum user {
description
"User-ordered list or leaf-list of items.";
}
}
description
"Ordered-by substatement value.";
}
container type {
description
"Type substatement.";
uses type-substmts;
list union-type {
description
"List of a union type substatements.";
uses type-substmts;
}
}
leaf units {
type string;
description
"Units substatement value.";
}
list unique {
description
"List of unique substatements.";
leaf-list node {
type yang:yang-identifier;
description
"List of nodes referenced by a unique substatement.";
}
}
leaf presence {
type boolean;
description
"Indicates whether a presence substatement is defined for
the container in the compiled schema. The textual argument
of 'presence' is reported via the locally resolved module
comparison (see the 'presence' leaf in 'local-substmts').";
}
uses ext-instance-stmts;
}
grouping module-substmts {
description
"All non-data-definition substatements of a module.";
leaf yang-version {
type string;
description
"YANG version substatement value.";
}
leaf prefix {
when "../../../locally-resolved";
type string;
description
"Prefix substatement value.";
}
container import {
when "../../../locally-resolved";
presence "Exists only when there is a difference in this import.";
description
"Import substatements.";
leaf module {
type yang:yang-identifier;
mandatory true;
description
"Imported module.";
}
leaf prefix {
type yang:yang-identifier;
mandatory true;
description
"Imported module prefix.";
}
leaf revision-date {
type yanglib:revision-identifier;
description
"Imported module revision-date.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses ext-instance-stmts;
}
container include {
when "../../../locally-resolved";
presence
"Exists only when there is a difference in this include.";
description
"Include substatements.";
leaf submodule {
type yang:yang-identifier;
mandatory true;
description
"Included submodule.";
}
leaf revision-date {
type yanglib:revision-identifier;
description
"Included submodule revision-date.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses ext-instance-stmts;
}
leaf organization {
type string;
description
"Organization substatement value.";
}
leaf contact {
type string;
description
"Contact substatement value.";
}
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
container extension {
when "../../../locally-resolved";
presence
"Exists only when there is a difference in this extension.";
description
"Extension substatements.";
leaf name {
type yang:yang-identifier;
mandatory true;
description
"Extension name.";
}
leaf argument {
type yang:yang-identifier;
description
"Argument substatement value.";
}
uses status-stmt;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses ext-instance-stmts;
}
container feature {
when "../../../locally-resolved";
presence
"Exists only when there is a difference in this feature.";
description
"Feature substatements.";
leaf name {
type yang:yang-identifier;
mandatory true;
description
"Feature name.";
}
uses if-feature-stmts;
uses status-stmt;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses ext-instance-stmts;
}
container identity {
description
"Identity substatements.";
leaf name {
type yang:yang-identifier;
mandatory true;
description
"Identity statement name.";
}
uses if-feature-stmts {
when "../../../locally-resolved";
}
leaf-list base {
when "../../../../locally-resolved";
type yang:yang-identifier;
description
"List of bases of an identity.";
}
uses ext-instance-stmts;
}
container ext-instance {
presence
"Exists only when there is a difference in this
extension-instance.";
description
"Extension-instance substatements.";
uses ext-instance-stmt;
}
}
grouping local-substmts {
description
"All locally-resolved-module-only statements that can be direct
substatements of a module or nested in a node.";
uses if-feature-stmts;
uses when-stmts;
leaf description {
type string;
description
"Description substatement value.";
}
leaf reference {
type string;
description
"Reference substatement value.";
}
uses status-stmt;
uses refine-node-substmts;
container type {
description
"Type substatement.";
uses type-local-substmts;
list union-type {
description
"List of a union type substatements.";
uses type-local-substmts;
}
}
leaf units {
type string;
description
"Units substatement value.";
}
leaf presence {
type string;
description
"Presence substatement value.";
}
uses ext-instance-stmts;
}
grouping conformance-type {
description
"Conformance type of a change.";
leaf conformance {
type enumeration {
enum editorial {
description
"Editorial change.";
}
enum backwards-compatible {
description
"Backwards-compatible change.";
}
enum non-backwards-compatible {
description
"Non-backwards-compatible change.";
}
}
mandatory true;
description
"Conformance information of a change in the compared YANG
modules.";
}
}
grouping change-info {
description
"Details of a single change.";
list changed {
key "stmt";
min-elements 1;
description
"List of changes.";
leaf stmt {
type stmt-type;
description
"Changed statement.";
}
leaf parent-stmt {
type stmt-type;
description
"Parent statement of the changed statement.";
}
leaf change {
type enumeration {
enum modified {
description
"Statement existed and was modified.";
}
enum added {
description
"Statement was added.";
}
enum removed {
description
"Statement was removed.";
}
enum moved {
description
"Statement was moved and the position affects the
meaning.";
}
}
mandatory true;
description
"Type of change of the statement.";
}
uses conformance-type;
}
}
grouping module-params {
description
"Identification details of a processed YANG module.";
leaf module {
type yang:yang-identifier;
description
"Compared module name.";
}
leaf revision {
type revision-or-empty;
description
"Compared module revision.";
}
leaf version {
type ysv:version;
description
"Compared module semantic version, if defined.";
}
list submodule {
key "name revision";
leaf name {
type yang:yang-identifier;
description
"Submodule name.";
}
leaf revision {
type revision-or-empty;
description
"Submodule revision.";
}
description
"Submodule of the main module.";
}
leaf-list enabled-feature {
type yang:yang-identifier;
description
"All the enabled features of the module.";
}
}
grouping local-info {
description
"Information about all the changed locally-resolved-module-only statements.";
list local-comparison {
description
"Information about locally-resolved-module-only statement changes.";
leaf parent-path {
type schema-stmt-path;
description
"Path to the parent statement. Not set if a direct
substatement of module or submodule.";
}
leaf identifier {
type string;
mandatory true;
description
"Identifier of the statement, may include a prefix.";
}
leaf stmt-type {
type enumeration {
enum choice {
description
"YANG statement 'choice' node.";
}
enum case {
description
"YANG statement 'case' node.";
}
enum input {
description
"YANG statement 'input' node.";
}
enum output {
description
"YANG statement 'output' node.";
}
enum uses {
description
"YANG statement 'uses' node.";
}
enum grouping {
description
"YANG statement 'grouping' node.";
}
enum augment {
description
"YANG statement 'augment' node.";
}
enum refine {
description
"YANG statement 'refine' node.";
}
enum typedef {
description
"YANG statement 'typedef'.";
}
}
mandatory true;
description
"Type of the changed data-definition statement.";
}
uses change-info;
container old {
description
"Changed local statements in the older revision of the YANG
module.";
uses local-substmts;
}
container new {
description
"Changed local statements in the newer revision of the YANG
module.";
uses local-substmts;
}
}
}
grouping node-info {
description
"Information about all the changed nodes.";
list node-comparison {
key "node";
ordered-by user;
description
"Information about data-definition (node) statement substatement
changes. Keeps the traversed order of the nodes by the
algorithm. It SHOULD follow the depth-first search order.";
leaf node {
type schema-node-path;
description
"Path to the changed data-definition statement.";
}
leaf node-type {
type enumeration {
enum container {
description
"YANG statement 'container' node.";
}
enum leaf {
description
"YANG statement 'leaf' node.";
}
enum leaf-list {
description
"YANG statement 'leaf-list' node.";
}
enum list {
description
"YANG statement 'list' node.";
}
enum anydata {
description
"YANG statement 'anydata' node.";
}
enum anyxml {
description
"YANG statement 'anyxml' node.";
}
enum rpc {
description
"YANG statement 'rpc' node.";
}
enum action {
description
"YANG statement 'action' node.";
}
enum notification {
description
"YANG statement 'notification' node.";
}
}
mandatory true;
description
"Type of the changed data-definition statement.";
}
uses change-info;
container old {
description
"All the node substatements in the older revision of the YANG
module.";
uses node-substmts;
}
container new {
description
"All the node substatements in the newer revision of the YANG
module.";
uses node-substmts;
}
}
}
sx:structure schema-comparison {
description
"Schema comparison details.";
list comparison {
must "locally-resolved or fully-resolved" {
description
"As the comparison input, locally resolved module, fully
resolved module, or both must be used.";
}
description
"Instance of a schema comparison of 2 YANG modules in different
revisions with all their imports.";
leaf locally-resolved {
type empty;
description
"Locally resolved module has been used for the comparison.";
reference
"RFC XXXX Section 3.1.";
}
leaf fully-resolved {
type empty;
description
"Fully resolved schema has been used for the comparison.";
reference
"RFC XXXX Section 3.2.";
}
container source {
description
"Source module information.";
uses module-params;
}
list source-import {
when "../fully-resolved";
key "module revision";
description
"List of source module imported modules information.";
uses module-params;
}
container target {
description
"Target module information.";
uses module-params;
}
list target-import {
when "../fully-resolved";
key "module revision";
description
"List of target module imported modules information.";
uses module-params;
}
uses conformance-type;
list module-comparison {
description
"Information about direct module statement substatement
changes.";
uses change-info;
container old {
description
"Changed statements in the older revision of the YANG
module.";
uses module-substmts;
}
container new {
description
"Changed statements in the newer revision of the YANG
module.";
uses module-substmts;
}
}
uses local-info {
when "locally-resolved";
}
uses node-info;
}
}
}
]]>Tree diagram
The “ietf-yang-schema-comparison-output” YANG module has the
following structure:
module: ietf-yang-schema-comparison-output
structure schema-comparison:
+-- comparison*
+-- locally-resolved? empty
+-- fully-resolved? empty
+-- source
| +-- module? yang:yang-identifier
| +-- revision? revision-or-empty
| +-- version? ysv:version
| +-- submodule* [name revision]
| | +-- name yang:yang-identifier
| | +-- revision revision-or-empty
| +-- enabled-feature* yang:yang-identifier
+-- source-import* [module revision]
| +-- module yang:yang-identifier
| +-- revision revision-or-empty
| +-- version? ysv:version
| +-- submodule* [name revision]
| | +-- name yang:yang-identifier
| | +-- revision revision-or-empty
| +-- enabled-feature* yang:yang-identifier
+-- target
| +-- module? yang:yang-identifier
| +-- revision? revision-or-empty
| +-- version? ysv:version
| +-- submodule* [name revision]
| | +-- name yang:yang-identifier
| | +-- revision revision-or-empty
| +-- enabled-feature* yang:yang-identifier
+-- target-import* [module revision]
| +-- module yang:yang-identifier
| +-- revision revision-or-empty
| +-- version? ysv:version
| +-- submodule* [name revision]
| | +-- name yang:yang-identifier
| | +-- revision revision-or-empty
| +-- enabled-feature* yang:yang-identifier
+-- conformance enumeration
+-- suggested-target-version ysv:version
+-- module-comparison*
| +-- changed* [stmt]
| | +-- stmt stmt-type
| | +-- parent-stmt? stmt-type
| | +-- change enumeration
| | +-- conformance enumeration
| +-- old
| | +-- yang-version? string
| | +-- prefix? string
| | +-- import!
| | | +-- module yang:yang-identifier
| | | +-- prefix yang:yang-identifier
| | | +-- revision-date? yanglib:revision-identifier
| | | +-- description? string
| | | +-- reference? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- include!
| | | +-- submodule yang:yang-identifier
| | | +-- revision-date? yanglib:revision-identifier
| | | +-- description? string
| | | +-- reference? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- organization? string
| | +-- contact? string
| | +-- description? string
| | +-- reference? string
| | +-- extension!
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- status enumeration
| | | +-- description? string
| | | +-- reference? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- feature!
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- status enumeration
| | | +-- description? string
| | | +-- reference? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- identity
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- base* string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- deviation!
| | | +-- target string
| | | +-- deviate*
| | | | +-- argument enumeration
| | | | +-- must*
| | | | | +-- condition? string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- default* string
| | | | +-- config? boolean
| | | | +-- mandatory? boolean
| | | | +-- min-elements? uint32
| | | | +-- max-elements? uint32
| | | | +-- type
| | | | | +-- name? string
| | | | | +-- range
| | | | | | +-- restriction? string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- length
| | | | | | +-- restriction? string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- fraction-digits? uint8
| | | | | +-- pattern*
| | | | | | +-- expression? string
| | | | | | +-- inverted? boolean
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- enum* [name]
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- if-feature* string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- value? int32
| | | | | | +-- status enumeration
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- bit* [name]
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- if-feature* string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- position? uint32
| | | | | | +-- status enumeration
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- path? string
| | | | | +-- require-instance? boolean
| | | | | +-- base* string
| | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- union-type*
| | | | | +-- name? string
| | | | | +-- range
| | | | | | +-- restriction? string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- length
| | | | | | +-- restriction? string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- fraction-digits? uint8
| | | | | +-- pattern*
| | | | | | +-- expression? string
| | | | | | +-- inverted? boolean
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- error-message? string
| | | | | | +-- error-app-tag? string
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- enum* [name]
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- if-feature* string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- value? int32
| | | | | | +-- status enumeration
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- bit* [name]
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- if-feature* string
| | | | | | +-- description? string
| | | | | | +-- reference? string
| | | | | | +-- position? uint32
| | | | | | +-- status enumeration
| | | | | | +-- ext-instance*
| | | | | | +-- module yang:yang-identifier
| | | | | | +-- name yang:yang-identifier
| | | | | | +-- argument? string
| | | | | | +-- substatements? anydata
| | | | | +-- path? string
| | | | | +-- require-instance? boolean
| | | | | +-- base* string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- units? string
| | | | +-- unique*
| | | | +-- node* yang:yang-identifier
| | | +-- description? string
| | | +-- reference? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- ext-instance!
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- new
| +-- yang-version? string
| +-- prefix? string
| +-- import!
| | +-- module yang:yang-identifier
| | +-- prefix yang:yang-identifier
| | +-- revision-date? yanglib:revision-identifier
| | +-- description? string
| | +-- reference? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- include!
| | +-- submodule yang:yang-identifier
| | +-- revision-date? yanglib:revision-identifier
| | +-- description? string
| | +-- reference? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- organization? string
| +-- contact? string
| +-- description? string
| +-- reference? string
| +-- extension!
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- status enumeration
| | +-- description? string
| | +-- reference? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- feature!
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- status enumeration
| | +-- description? string
| | +-- reference? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- identity
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- base* string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- deviation!
| | +-- target string
| | +-- deviate*
| | | +-- argument enumeration
| | | +-- must*
| | | | +-- condition? string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- default* string
| | | +-- config? boolean
| | | +-- mandatory? boolean
| | | +-- min-elements? uint32
| | | +-- max-elements? uint32
| | | +-- type
| | | | +-- name? string
| | | | +-- range
| | | | | +-- restriction? string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- length
| | | | | +-- restriction? string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- fraction-digits? uint8
| | | | +-- pattern*
| | | | | +-- expression? string
| | | | | +-- inverted? boolean
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- enum* [name]
| | | | | +-- name yang:yang-identifier
| | | | | +-- if-feature* string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- value? int32
| | | | | +-- status enumeration
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- bit* [name]
| | | | | +-- name yang:yang-identifier
| | | | | +-- if-feature* string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- position? uint32
| | | | | +-- status enumeration
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- path? string
| | | | +-- require-instance? boolean
| | | | +-- base* string
| | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- union-type*
| | | | +-- name? string
| | | | +-- range
| | | | | +-- restriction? string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- length
| | | | | +-- restriction? string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- fraction-digits? uint8
| | | | +-- pattern*
| | | | | +-- expression? string
| | | | | +-- inverted? boolean
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- error-message? string
| | | | | +-- error-app-tag? string
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- enum* [name]
| | | | | +-- name yang:yang-identifier
| | | | | +-- if-feature* string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- value? int32
| | | | | +-- status enumeration
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- bit* [name]
| | | | | +-- name yang:yang-identifier
| | | | | +-- if-feature* string
| | | | | +-- description? string
| | | | | +-- reference? string
| | | | | +-- position? uint32
| | | | | +-- status enumeration
| | | | | +-- ext-instance*
| | | | | +-- module yang:yang-identifier
| | | | | +-- name yang:yang-identifier
| | | | | +-- argument? string
| | | | | +-- substatements? anydata
| | | | +-- path? string
| | | | +-- require-instance? boolean
| | | | +-- base* string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- units? string
| | | +-- unique*
| | | +-- node* yang:yang-identifier
| | +-- description? string
| | +-- reference? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- ext-instance!
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- local-comparison*
| +-- parent-path? schema-stmt-path
| +-- identifier string
| +-- stmt-type enumeration
| +-- changed* [stmt]
| | +-- stmt stmt-type
| | +-- parent-stmt? stmt-type
| | +-- change enumeration
| | +-- conformance enumeration
| +-- old
| | +-- if-feature* string
| | +-- when*
| | | +-- condition? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- description? string
| | +-- reference? string
| | +-- status enumeration
| | +-- must*
| | | +-- condition? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- default* string
| | +-- config? boolean
| | +-- mandatory? boolean
| | +-- min-elements? uint32
| | +-- max-elements? uint32
| | +-- type
| | | +-- name? string
| | | +-- range
| | | | +-- restriction? string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- length
| | | | +-- restriction? string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- fraction-digits? uint8
| | | +-- pattern*
| | | | +-- expression? string
| | | | +-- inverted? boolean
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- enum* [name]
| | | | +-- name yang:yang-identifier
| | | | +-- if-feature* string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- value? int32
| | | | +-- status enumeration
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- bit* [name]
| | | | +-- name yang:yang-identifier
| | | | +-- if-feature* string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- position? uint32
| | | | +-- status enumeration
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- path? string
| | | +-- require-instance? boolean
| | | +-- base* string
| | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- union-type*
| | | +-- name? string
| | | +-- range
| | | | +-- restriction? string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- length
| | | | +-- restriction? string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- fraction-digits? uint8
| | | +-- pattern*
| | | | +-- expression? string
| | | | +-- inverted? boolean
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- error-message? string
| | | | +-- error-app-tag? string
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- enum* [name]
| | | | +-- name yang:yang-identifier
| | | | +-- if-feature* string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- value? int32
| | | | +-- status enumeration
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- bit* [name]
| | | | +-- name yang:yang-identifier
| | | | +-- if-feature* string
| | | | +-- description? string
| | | | +-- reference? string
| | | | +-- position? uint32
| | | | +-- status enumeration
| | | | +-- ext-instance*
| | | | +-- module yang:yang-identifier
| | | | +-- name yang:yang-identifier
| | | | +-- argument? string
| | | | +-- substatements? anydata
| | | +-- path? string
| | | +-- require-instance? boolean
| | | +-- base* string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- units? string
| | +-- key? string
| | +-- unique* string
| | +-- presence? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- new
| +-- if-feature* string
| +-- when*
| | +-- condition? string
| | +-- description? string
| | +-- reference? string
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- description? string
| +-- reference? string
| +-- status enumeration
| +-- must*
| | +-- condition? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- default* string
| +-- config? boolean
| +-- mandatory? boolean
| +-- min-elements? uint32
| +-- max-elements? uint32
| +-- type
| | +-- name? string
| | +-- range
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- length
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- fraction-digits? uint8
| | +-- pattern*
| | | +-- expression? string
| | | +-- inverted? boolean
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- enum* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- value? int32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- bit* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- position? uint32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- path? string
| | +-- require-instance? boolean
| | +-- base* string
| | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- union-type*
| | +-- name? string
| | +-- range
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- length
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- fraction-digits? uint8
| | +-- pattern*
| | | +-- expression? string
| | | +-- inverted? boolean
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- enum* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- value? int32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- bit* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- position? uint32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- path? string
| | +-- require-instance? boolean
| | +-- base* string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- units? string
| +-- key? string
| +-- unique* string
| +-- presence? string
| +-- ext-instance*
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- node-comparison* [node]
+-- node schema-node-path
+-- node-type enumeration
+-- changed* [stmt]
| +-- stmt stmt-type
| +-- parent-stmt? stmt-type
| +-- change enumeration
| +-- conformance enumeration
+-- old
| +-- if-feature* string
| +-- when*
| | +-- condition? string
| | +-- description? string
| | +-- reference? string
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- description? string
| +-- reference? string
| +-- status enumeration
| +-- must*
| | +-- condition? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- default* string
| +-- config? boolean
| +-- mandatory? boolean
| +-- min-elements? uint32
| +-- max-elements? uint32
| +-- key* yang:yang-identifier
| +-- ordered-by? enumeration
| +-- type
| | +-- name? string
| | +-- range
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- length
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- fraction-digits? uint8
| | +-- pattern*
| | | +-- expression? string
| | | +-- inverted? boolean
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- enum* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- value? int32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- bit* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- position? uint32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- path? string
| | +-- require-instance? boolean
| | +-- base* string
| | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- union-type*
| | +-- name? string
| | +-- range
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- length
| | | +-- restriction? string
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- fraction-digits? uint8
| | +-- pattern*
| | | +-- expression? string
| | | +-- inverted? boolean
| | | +-- description? string
| | | +-- reference? string
| | | +-- error-message? string
| | | +-- error-app-tag? string
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- enum* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- value? int32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- bit* [name]
| | | +-- name yang:yang-identifier
| | | +-- if-feature* string
| | | +-- description? string
| | | +-- reference? string
| | | +-- position? uint32
| | | +-- status enumeration
| | | +-- ext-instance*
| | | +-- module yang:yang-identifier
| | | +-- name yang:yang-identifier
| | | +-- argument? string
| | | +-- substatements? anydata
| | +-- path? string
| | +-- require-instance? boolean
| | +-- base* string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- units? string
| +-- unique*
| | +-- node* yang:yang-identifier
| +-- presence? string
| +-- ext-instance*
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- new
+-- if-feature* string
+-- when*
| +-- condition? string
| +-- description? string
| +-- reference? string
| +-- status enumeration
| +-- ext-instance*
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- description? string
+-- reference? string
+-- status enumeration
+-- must*
| +-- condition? string
| +-- description? string
| +-- reference? string
| +-- error-message? string
| +-- error-app-tag? string
| +-- ext-instance*
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- default* string
+-- config? boolean
+-- mandatory? boolean
+-- min-elements? uint32
+-- max-elements? uint32
+-- key* yang:yang-identifier
+-- ordered-by? enumeration
+-- type
| +-- name? string
| +-- range
| | +-- restriction? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- length
| | +-- restriction? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- fraction-digits? uint8
| +-- pattern*
| | +-- expression? string
| | +-- inverted? boolean
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- enum* [name]
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- description? string
| | +-- reference? string
| | +-- value? int32
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- bit* [name]
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- description? string
| | +-- reference? string
| | +-- position? uint32
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- path? string
| +-- require-instance? boolean
| +-- base* string
| +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- union-type*
| +-- name? string
| +-- range
| | +-- restriction? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- length
| | +-- restriction? string
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- fraction-digits? uint8
| +-- pattern*
| | +-- expression? string
| | +-- inverted? boolean
| | +-- description? string
| | +-- reference? string
| | +-- error-message? string
| | +-- error-app-tag? string
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- enum* [name]
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- description? string
| | +-- reference? string
| | +-- value? int32
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- bit* [name]
| | +-- name yang:yang-identifier
| | +-- if-feature* string
| | +-- description? string
| | +-- reference? string
| | +-- position? uint32
| | +-- status enumeration
| | +-- ext-instance*
| | +-- module yang:yang-identifier
| | +-- name yang:yang-identifier
| | +-- argument? string
| | +-- substatements? anydata
| +-- path? string
| +-- require-instance? boolean
| +-- base* string
| +-- ext-instance*
| +-- module yang:yang-identifier
| +-- name yang:yang-identifier
| +-- argument? string
| +-- substatements? anydata
+-- units? string
+-- unique*
| +-- node* yang:yang-identifier
+-- presence? string
+-- ext-instance*
+-- module yang:yang-identifier
+-- name yang:yang-identifier
+-- argument? string
+-- substatements? anydata
Change Conformance Principles
This appendix clarifies the general principles based on which
statement changes are categorized. They are not meant to replace
any specification but rather help with understanding it.
Editorial change
An editorial change does not affect valid YANG data of the
semantics of the YANG module in any way. That is, it does not
make the valid data value space smaller or larger and it must
remain exactly the same as in the module revision without the
change. Also, for a change to be editorial, it must not affect
any YANG module importing the changed YANG module.
In addition to obvious editorial changes such as fixing a typo
in a "description", changing the local "prefix" of the module
is also categorized as editorial because it does not affect
importing modules. Or, replacing a "uses" statement directly
with the nodes in the referenced "grouping" without any other
changes.
Backwards-compatible change
For a change to be backwards-compatible, it has to expand the
value space of valid YANG data. That is, all the valid YANG
data nodes and values before the change must remain valid but
additional nodes or values can also become valid after the
change. Also, backwards-compatible changes may influence
importing modules but must not cause them to become invalid. In
other words, they may expose new statements whose removal would
then be considered a non-backwards-compatible change but
generally must not change the already exposed statements.
For some examples, the majority of possible
backwards-compatible changes are specifically mentioned
directly in Section 11 of .
Non-backwards-compatible change
If a change is not editorial nor backwards-compatible, it is
then categorized as non-backwards-compatible. Such changes
shrink the value space of valid YANG data, causing some
previously valid nodes or values to no longer be valid. Also,
any change that may cause an importing module to become invalid
according to the YANG specification must be non-backwards-compatible.
Examples of less common or less obvious compatibility-breaking
changes are changing the "yang-version" of a YANG module or
expanding the size of a "type". The former change may break
importing modules because of specific rules defined for the
"import" statement and the target module's YANG version.
Changing a "type" of a leaf from "uint32" to "uint64" may seem
to fit the definition of a backwards-compatible change, but it
may not be so for some data encodings that use a fixed binary
data chunk (which would grow in size) or even a text format
that may use a different encoding for the two types.
Specifically, the JSON YANG data format
encodes a "uint32" value as a JSON
number but a "uint64" as a JSON string.
Comparison Examples
This section provides several examples of the output from the
comparison algorithm defined in this document to illustrate its
behavior on actual YANG modules. The example YANG modules are
missing “description” or “reference” statements for better
readability. Changes are represented as JSON encoded
YANG instance data following the
“ietf-yang-schema-comparison-output” module definition in
for the output.
In this example, two new leaves are added to the module.
In the generated output, there are changes in both locally
resolved module and fully resolved schema. The changes are
backward-compatible because the new nodes are added without
affecting the order of the existing schema nodes.
An example module comparison in which a typedef length
restriction is relaxed and a new leaf is added.
The generated diff includes both locally resolved and fully
resolved changes. In the local comparison, the specific range
change is reported as backward-compatible because the
restriction was relaxed. In the fully resolved node comparison,
the exact same change is reported because the leaf uses the
same typedef, whose change also affects the leaf. The newly
added leaf is also reported and marked as backward-compatible.