Feb 15th 2023 update

external/graphqlparser/README.md

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+# libgraphqlparser
+
+libgraphqlparser is a parser for
+[GraphQL](http://graphql.org/), a query language for describing data
+requirements on complex application data models, implemented in C++11.
+It can be used on its own in C++ code (or in C code via the pure C API
+defined in the `c` subdirectory), or you can use it as the basis for an
+extension module for your favorite programming language instead of writing
+your own parser from scratch.
+
+## Example
+
+The provided `dump_json_ast` is a simple program that reads GraphQL
+text on stdin and prints a JSON representation of the AST to stdout.
+
+The `python` subdirectory contains an example Python binding for the
+pure C API.
+
+## Requirements
+
+libgraphqlparser requires a C++ compiler that supports C++11. It
+also requires Mac OS X or Linux.
+
+To run tests, first, compile and install the library as described above. Then,
+please download googletest from
+https://github.com/google/googletest/archive/release-1.8.0.zip
+and unzip it in the `test` subdirectory. In consequence, a folder
+`googletest-release-1.8.0` should be contained in `test`. Next, within the
+`test` folder, run `cmake .` and `make` to generate the `runTests` binary.
+To execute the tests run `./test/runTests` from the main folder.
+
+## Building libgraphqlparser
+
+libgraphqlparser is built with [CMake](http://www.cmake.org/). If a
+sufficiently-recent version of [Flex](http://flex.sourceforge.net/) and [Bison](http://www.gnu.org/software/bison/) are installed on your
+system, it will use them; otherwise, it will rely on the checked-in
+`parser.tab.{c,h}pp` and `lexer.{h,cpp}`.
+
+To build libgraphqlparser from source:
+
+```
+$ # inside the project root:
+$ cmake .
+$ make
+```
+
+Then, to install it on your system:
+
+```
+$ make install
+```
+
+## How libgraphqlparser works
+
+libgraphqlparser uses flex and bison to generate a C++ parser for
+GraphQL. These tools work well but have idiosyncratic interfaces by
+modern standards, so GraphQLParser.h provides a simple interface to
+parse GraphQL.
+
+In order to make it simpler to write code based around the GraphQL
+AST, libgraphqlparser includes an extremely simple code generation
+framework in the `ast/` subdirectory. This framework is used to build
+the AST classes themselves, as well as a visitor over the AST. It may
+be easier to understand the output of the generation steps directly
+(i.e., Ast.h, Ast.cpp, and AstVisitor.h) rather than trying to read
+the generation scripts. Simply building libgraphqlparser will cause
+these files to be generated.
+
+libgraphqlparser also uses the AST generation framework to build a
+pure C API in the `c` subdirectory. This API can be used from C code,
+and it should also simplify the task of creating bindings to other
+programming languages.
+
+## License
+
+libgraphqlparser is MIT-licensed.
+
+## Related Projects
+
+- [graphql-parser (Ruby interface)](https://github.com/Shopify/graphql-parser)
+- [py-graphqlparser (Python interface)](https://github.com/elastic-coders/py-graphqlparser)
+- [graphql_parser (Elixir interface)](https://github.com/aarvay/graphql_parser)
+- [graphql-parser-php (PHP interface)](https://github.com/dosten/graphql-parser-php)
+- [graphql-libgraphqlparser (Ruby interface)](https://github.com/rmosolgo/graphql-libgraphqlparser-ruby)
+
+## Contributing to this repo
+
+This repository is managed by EasyCLA. Project participants must sign the free ([GraphQL Specification Membership agreement](https://preview-spec-membership.graphql.org) before making a contribution. You only need to do this one time, and it can be signed by [individual contributors](http://individual-spec-membership.graphql.org/) or their [employers](http://corporate-spec-membership.graphql.org/).
+
+To initiate the signature process please open a PR against this repo. The EasyCLA bot will block the merge if we still need a membership agreement from you.
+
+You can find [detailed information here](https://github.com/graphql/graphql-wg/tree/main/membership). If you have issues, please email [operations@graphql.org](mailto:operations@graphql.org).
+
+If your company benefits from GraphQL and you would like to provide essential financial support for the systems and people that power our community, please also consider membership in the [GraphQL Foundation](https://foundation.graphql.org/join).