Piqi is a set of languages and open-source tools for working with structured data. It includes:
A cross-language data serialization system compatible with Google Protocol Buffers. It allows programs implemented in various languages to exchange and persist data in a portable manner.
Piq -- a human-friendly typed data representation language. It is designed to be more convenient for representing, viewing and editing data than JSON, XML, CSV, S-expressions and other formats.
Piqi -- a universal data definition language. It can be used as a schema language for JSON, XML, Protocol Buffers and Piq.
Tools for validating, pretty-printing and converting data between Piq, JSON, XML and Protocol Buffers formats.
Piqi-RPC -- an RPC-over-HTTP system for Erlang. It provides a simple way to expose Erlang services via JSON, XML and Google Protocol Buffers over HTTP.
As a data serialization system, Piqi implements native support for OCaml and Erlang. Connectivity with other programming languages is provided via Google Protocol Buffers. Overall, Piqi provides a more natural mapping to functional programming languages compared to various serialization systems that were originally designed for imperative or object-oriented languages.
Piqi was inspired by Google Protocol Buffers and specially designed to be largely compatible with it. Like Protocol Buffers, Piqi relies on type definitions and supports data schema evolution. The main difference is that Piqi has a richer data model, high-level modules and a powerful data representation language (Piq).
Combination of the data representation (Piq) and the data definition (Piqi) languages is similar to the concept of "valid XML" (i.e. XML conforming to some XML Schema). However, unlike XML, Piq has a concise, clean syntax and a data model similar to those of high-level programming languages.
Full project description and documentation can be found at http://piqi.org
See INSTALL for the installation instructions.
If you found a bug or have any suggestions please submit a GitHub issue: https://github.com/alavrik/piqi/issues
Participation and patches are very welcome! The best way to submit a
contribution is to open a pull request on GitHub against the
For discussions about the usage, development, and future of Piqi there is the Piqi Google Group: http://groups.google.com/group/piqi
README this file INSTALL general installation instructions INSTALL.erlang instructions for building Piqi for Erlang INSTALL.ocaml instructions for building Piqi for OCaml INSTALL.windows instructions for building Piqi on Windows setenv.sh environment configuration for running tests setenv-mingw.sh environment configuration for Windows/MinGW builds LICENSE license NOTICE copyright notice CHANGES release history VERSION current version configure configure script Makefile top-level Makefile make/ makefiles and build scripts deps/ third-party components (see NOTICE for details) piqi-camlp4/ Piqi syntax extensions for OCaml piqicc/ Piqi compiler compiler (used only during boostrap) piqic/ Piq interface compiler(s) for OCaml piqi-tools/ "piqi" command-line utility (piqi tools) piqi Piqi self-specification piqilib/ Piqi common library piqirun-ocaml/ Piqi runtime library for OCaml examples/ examples tests/ tests for various piqi functionality; see tests/README doc/ Piqi documentation editors/ text editor plugins for .piq and .piqi files