Ratus

Ratus is a simple expression language that can be used to easily extend Python applications with an embedded expression language. Evaluating basic expressions is as simple as:

from ratus import Evaluator

evaluator = Evaluator()
evaluator.evaluate("1 + 1") # => 1
evaluator.evaluate("1 > 1") # => False
evaluator.evaluate("if(1 < 2, 10, 5)") #  => 5

For more information, please check out the docs

What's in a name?

When I first started this project I did a bit of research around parsing techniques as this is really the most complex part. One idea that that really stuck out to me was packrat parsing. This technique allows for linear time parsing, as opposed to the usual exponential time of backtracking parsing.

Currently packrat parsing isn't implemented for ratus but I'm working on it!

Roadmap

v1.0.0

• Fully document all features
  • API
  • Grammar
• Fix known bugs
  • Don't require functions to be the root of an expression
    • e.g. pow(2, 2) + 1 should be allowed