3 ms·

Skylark in Go: An Interpreter for Skylark, Implemented in Go

9 points by rjammala 9y ago

lobster_johnson 9y ago
This is the configuration language that Google uses internally. It's used in Bazel (which was open-sourced from Google's Blaze) and, I believe, in many other places inside Google. Unlike Google's Jsonnet, which doesn't seem to have become very popular, it goes way beyond mere declarative templating, as it's actually a minimal implementation of Python, complete with functions, lambdas, for loops, etc. The Google documentation for Bazel's BUILD files provides some context: The concrete syntax of BUILD files is a subset of Python. Originally, the syntax was that of Python, but experience showed that users rarely used more than a tiny subset of Python's features, and when they did, it often resulted in complex and fragile BUILD files. In many cases, the use of such features was unnecessary, and the same result could be achieved by using an external program, e.g. via a genrule build rule. Crucially, programs in the build language are unable to perform arbitrary I/O (though many users try!). This invariant makes the interpretation of BUILD files hermetic, i.e. dependent only on a known set of inputs, which is essential for ensuring that builds are reproducible.
- sparkprime 9y ago
  Your comparison with Jsonnet is not accurate. Jsonnet is thriving, now also has a Go implementation and lots of adoption especially in the Kubernetes community. It has nearly 1000 github stars. It is also a full programming language, and has all the features you listed.
  - nikolay 9y ago
    I disagree that it's thriving! It's a pretty weird combination of a JavaScript-like interpreter with non-JavaScript stdlib and bizarre choice of keywords, for example, 'local' and not 'var'/'let,' etc. It's capabilities as a language are pretty limited, so, although at first sight, it looks great, it's pretty limited, and even Jinja2 gives you more, so, you see more and more people combining Jinja2 with Jsonnet, which is proof that it's doomed.
  - nikolay 9y ago
    TOML, which is newer, has nearly 6.6K stars. Hjson has 1.5K, JSON5 has 1.8K, HCL has 1.2K, and ICL. At the same time, a newcomer such as ICL [1] has less than 10. [1]: https://github.com/archipaorg/icl https://github.com/archipaorg/icl

9 points by rjammala 9y ago

This is the configuration language that Google uses internally. It's used in Bazel (which was open-sourced from Google's Blaze) and, I believe, in many other places inside Google. Unlike Google's Jsonnet, which doesn't seem to have become very popular, it goes way beyond mere declarative templating, as it's actually a minimal implementation of Python, complete with functions, lambdas, for loops, etc. The Google documentation for Bazel's BUILD files provides some context: The concrete syntax of BUILD files is a subset of Python. Originally, the syntax was that of Python, but experience showed that users rarely used more than a tiny subset of Python's features, and when they did, it often resulted in complex and fragile BUILD files. In many cases, the use of such features was unnecessary, and the same result could be achieved by using an external program, e.g. via a genrule build rule. Crucially, programs in the build language are unable to perform arbitrary I/O (though many users try!). This invariant makes the interpretation of BUILD files hermetic, i.e. dependent only on a known set of inputs, which is essential for ensuring that builds are reproducible.

sparkprime 9y ago
Your comparison with Jsonnet is not accurate. Jsonnet is thriving, now also has a Go implementation and lots of adoption especially in the Kubernetes community. It has nearly 1000 github stars. It is also a full programming language, and has all the features you listed.
- nikolay 9y ago
  I disagree that it's thriving! It's a pretty weird combination of a JavaScript-like interpreter with non-JavaScript stdlib and bizarre choice of keywords, for example, 'local' and not 'var'/'let,' etc. It's capabilities as a language are pretty limited, so, although at first sight, it looks great, it's pretty limited, and even Jinja2 gives you more, so, you see more and more people combining Jinja2 with Jsonnet, which is proof that it's doomed.
- nikolay 9y ago
  TOML, which is newer, has nearly 6.6K stars. Hjson has 1.5K, JSON5 has 1.8K, HCL has 1.2K, and ICL. At the same time, a newcomer such as ICL [1] has less than 10. [1]: https://github.com/archipaorg/icl https://github.com/archipaorg/icl