aosp12/external/jsoncpp/doc/jsoncpp.dox

/**
\mainpage
\section _intro Introduction

<a HREF="http://www.json.org/">JSON (JavaScript Object Notation)</a>
 is a lightweight data-interchange format.

Here is an example of JSON data:
\verbatim
{
    "encoding" : "UTF-8",
    "plug-ins" : [
        "python",
        "c++",
        "ruby"
        ],
    "indent" : { "length" : 3, "use_space": true }
}
\endverbatim
<b>JsonCpp</b> supports comments as <i>meta-data</i>:
\code
// Configuration options
{
    // Default encoding for text
    "encoding" : "UTF-8",

    // Plug-ins loaded at start-up
    "plug-ins" : [
        "python",
        "c++",  // trailing comment
        "ruby"
        ],

    // Tab indent size
    // (multi-line comment)
    "indent" : { /*embedded comment*/ "length" : 3, "use_space": true }
}
\endcode

\section _features Features
- read and write JSON document
- attach C++ style comments to element during parsing
- rewrite JSON document preserving original comments

Notes: Comments used to be supported in JSON but were removed for
portability (C like comments are not supported in Python). Since
comments are useful in configuration/input file, this feature was
preserved.

\section _example Code example

\code
Json::Value root;   // 'root' will contain the root value after parsing.
std::cin >> root;

// You can also read into a particular sub-value.
std::cin >> root["subtree"];

// Get the value of the member of root named 'encoding',
// and return 'UTF-8' if there is no such member.
std::string encoding = root.get("encoding", "UTF-8" ).asString();

// Get the value of the member of root named 'plug-ins'; return a 'null' value if
// there is no such member.
const Json::Value plugins = root["plug-ins"];

// Iterate over the sequence elements.
for ( int index = 0; index < plugins.size(); ++index )
   loadPlugIn( plugins[index].asString() );

// Try other datatypes. Some are auto-convertible to others.
foo::setIndentLength( root["indent"].get("length", 3).asInt() );
foo::setIndentUseSpace( root["indent"].get("use_space", true).asBool() );

// Since Json::Value has an implicit constructor for all value types, it is not
// necessary to explicitly construct the Json::Value object.
root["encoding"] = foo::getCurrentEncoding();
root["indent"]["length"] = foo::getCurrentIndentLength();
root["indent"]["use_space"] = foo::getCurrentIndentUseSpace();

// If you like the defaults, you can insert directly into a stream.
std::cout << root;
// Of course, you can write to `std::ostringstream` if you prefer.

// If desired, remember to add a linefeed and flush.
std::cout << std::endl;
\endcode

\section _advanced Advanced usage

Configure *builders* to create *readers* and *writers*. For
configuration, we use our own `Json::Value` (rather than
standard setters/getters) so that we can add
features without losing binary-compatibility.

\code
// For convenience, use `writeString()` with a specialized builder.
Json::StreamWriterBuilder wbuilder;
wbuilder["indentation"] = "\t";
std::string document = Json::writeString(wbuilder, root);

// Here, using a specialized Builder, we discard comments and
// record errors as we parse.
Json::CharReaderBuilder rbuilder;
rbuilder["collectComments"] = false;
std::string errs;
bool ok = Json::parseFromStream(rbuilder, std::cin, &root, &errs);
\endcode

Yes, compile-time configuration-checking would be helpful,
but `Json::Value` lets you
write and read the builder configuration, which is better! In other words,
you can configure your JSON parser using JSON.

CharReaders and StreamWriters are not thread-safe, but they are re-usable.
\code
Json::CharReaderBuilder rbuilder;
cfg >> rbuilder.settings_;
std::unique_ptr<Json::CharReader> const reader(rbuilder.newCharReader());
reader->parse(start, stop, &value1, &errs);
// ...
reader->parse(start, stop, &value2, &errs);
// etc.
\endcode

\section _pbuild Build instructions
The build instructions are located in the file
<a HREF="https://github.com/open-source-parsers/jsoncpp/blob/master/README.md">README.md</a> in the top-directory of the project.

The latest version of the source is available in the project's GitHub repository:
<a HREF="https://github.com/open-source-parsers/jsoncpp/">
jsoncpp</a>

\section _news What's New?
The description of latest changes can be found in
<a HREF="https://github.com/open-source-parsers/jsoncpp/wiki/NEWS">
  the NEWS wiki
</a>.

\section _rlinks Related links
- <a HREF="http://www.json.org/">JSON</a> Specification and alternate language implementations.
- <a HREF="http://www.yaml.org/">YAML</a> A data format designed for human readability.
- <a HREF="http://www.cl.cam.ac.uk/~mgk25/unicode.html">UTF-8 and Unicode FAQ</a>.

\section _plinks Old project links
- <a href="https://sourceforge.net/projects/jsoncpp/">https://sourceforge.net/projects/jsoncpp/</a>
- <a href="http://jsoncpp.sourceforge.net">http://jsoncpp.sourceforge.net</a>
- <a href="http://sourceforge.net/projects/jsoncpp/files/">http://sourceforge.net/projects/jsoncpp/files/</a>
- <a href="http://jsoncpp.svn.sourceforge.net/svnroot/jsoncpp/trunk/">http://jsoncpp.svn.sourceforge.net/svnroot/jsoncpp/trunk/</a>
- <a href="http://jsoncpp.sourceforge.net/old.html">http://jsoncpp.sourceforge.net/old.html</a>

\section _license License
See file <a href="https://github.com/open-source-parsers/jsoncpp/blob/master/LICENSE"><code>LICENSE</code></a> in the top-directory of the project.

Basically JsonCpp is licensed under MIT license, or public domain if desired
and recognized in your jurisdiction.

\author Baptiste Lepilleur <blep@users.sourceforge.net> (originator)
\author Christopher Dunn <cdunn2001@gmail.com> (primary maintainer)
\version \include version
We make strong guarantees about binary-compatibility, consistent with
<a href="http://apr.apache.org/versioning.html">the Apache versioning scheme</a>.
\sa version.h
*/