A GraphQL query parser in C++ with C and C++ APIs
C++ Python C CMake Go
Latest commit 8fd351b Jan 10, 2017 @swolchok swolchok committed on GitHub Merge pull request #45 from graphql/schema-parser
Schema parser
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ast AST for experimental schema definitions Dec 27, 2016
c Expose API to parse with experimental schema definition support Dec 29, 2016
cmake Adding pkg-config generation to CMakeLists May 10, 2016
go Adding pkg-config generation to CMakeLists May 10, 2016
python Make out-of-source build work Sep 14, 2015
test Add automated schema-kitchen-sink test Dec 29, 2016
.gitignore Automatically generate the repetitive parts of JsonVisitor Dec 27, 2016
.travis.yml set CMAKE_BUILD_TYPE to Debug for testing Dec 24, 2016
AstNode.h Initial import Aug 13, 2015
CMakeLists.txt Automatically generate the repetitive parts of JsonVisitor Dec 27, 2016
CONTRIBUTING.md Initial import Aug 13, 2015
GraphQLParser.cpp Expose API to parse with experimental schema definition support Dec 29, 2016
GraphQLParser.h Expose API to parse with experimental schema definition support Dec 29, 2016
JsonVisitor.cpp Automatically generate the repetitive parts of JsonVisitor Dec 27, 2016
JsonVisitor.h Automatically generate the repetitive parts of JsonVisitor Dec 27, 2016
LICENSE Initial import Aug 13, 2015
PATENTS Initial import Aug 13, 2015
README.md Add _another_ Ruby Interface Oct 24, 2016
dump_json_ast.cpp dump_json_ast: don't leak return value of graphql_ast_to_json Oct 8, 2015
lexer.cpp Parser code for schema definition Dec 29, 2016
lexer.h Parser code for schema definition Dec 29, 2016
lexer.lpp Parser code for schema definition Dec 29, 2016
libgraphqlparser.pc.in Adding pkg-config generation to CMakeLists May 10, 2016
location.hh tidy up bison output Dec 22, 2016
parser.tab.cpp Parser code for schema definition Dec 29, 2016
parser.tab.hpp Parser code for schema definition Dec 29, 2016
parser.ypp Parser code for schema definition Dec 29, 2016
position.hh tidy up bison output Dec 22, 2016
stack.hh tidy up bison output Dec 22, 2016
syntaxdefs.h Make lexer re-entrant and thread it through parser Sep 16, 2015

README.md

libgraphqlparser

libgraphqlparser is a parser for GraphQL, a query language created by Facebook 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, please download googletest from https://github.com/google/googletest/archive/release-1.8.0.zip and unzip it in the test subdirectory.

Building libgraphqlparser

libgraphqlparser is built with CMake. If a sufficiently-recent version of Flex and 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 BSD-licensed. We also provide an additional patent grant.

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