Expr is a Go-centric expression language designed to deliver dynamic configurations with unparalleled accuracy, safety, and speed.

expr repl demo

In this release:

• Added support for variables.

  let foo = filter(tweets, .Text contains "foo");
  let name = foo?.Author?.Name ?? "unknown";
  upper(name)

• Added configuration to enable/disable builtin functions.
• Added a bunch of optimizations for builtin function combinations:
  • len(filter()) and map(filter())
  • filter()[0] and filter()[-1]
• Added a bunch of new builtin functions:
  • sort, sortBy
  • groupBy
  • toPairs, fromPairs
  • take, reduce, mean, median.
• Fixed in-range optimization to be only applied to integers.
• Fixed float folding optimization.
• Fixed duration*integer mutliplications.
• Improved language and developer documentation.

Examples:

tweets | filter(.Size < 280) | map(.Content) | join(" -- ")

filter(posts, {
 let span = now() - .CreatedAt;
 let limit = 7 * duration("24h");
 span >= limit
})