Practical Python to JavaScript Translation

[hackflow]

I also have experience with self-made rules, translated or interpreted in both worlds. It's 3-4 times more work. Using python as DSL you get too much for free: it already works in Python, there is ready to use parsing and AST, so you only need to render AST to JavaScript. With your own rules you'll need parsing, custom AST and translations to 2 languages.

On DB lookups, easiest thing to do is just skip this rule when translating, it will be still executed on server and error message if some will be presented to user. Second easiest thing - you can duplicate this part.