Question

I’m working on a project which will do some complicated analyzing on some user-supplied input. There will be 3 parts of the code:

1) Input supplied by user, such as keywords

2) Rules, such as if keyword 1 is repeated 3 times in keyword 5, do this, etc.

3) And the analyzing itself which executes the rules and processes the user input, and generates the output necessary based on the processing.

Naturally this will lead to a lot of spaghetti code and many, many if statements in the processing code. I want to avoid that, and keep the rules (i.e. the if statements) separately from the code which loops through the user input and generates the output.

How can I do that, i.e. what is the best way?

Answer 1

If you have enough rules that you want to externalize, you could try using a business rules engines, like Drools in Java.

A business rules engine is a software system that executes one or more business rules in a runtime production environment. The rules might come from legal regulation (‘An employee can be fired for any reason or no reason but not for an illegal reason’), company policy (‘All customers that spend more than $100 at one time will receive a 10% discount’), or other sources. (Wikipedia)

It could be a little bit overhead depending of what you’re trying to do. In my company we’re using such kind of tools for our quality analysis tool.