RegExHelper | A UI to help with writing Regular Expressions | Regex library

Here's my scenario:

There is a collection of objects where each object contains a Dictionary. The user can build a set of queries for this collection from another app to obtain a subset by selecting a Key in the Dictionary, an operator such as > or CONTAINS, etc., and a Value. They can also balance parenthesis to create groups of queries and select AND/OR operators to combine the queries.

As an example, let's say I have a collection of Car objects and the Dictionary contains keys for Make, Model, and Year.

My app is getting these queries in the form of a string like so:

"((Make = Honda) AND (Model CONTAINS Civic)) || (Year >= 2015)"

This tells me that from the collection of Car objects that I want cars that have Dictionary keys/values of and OR

So, I parse these out and put them into a QueryClass containing three string fields for the Key, the Operator, and the Value. I also keep track of the operator between the queries, and if they are in a group of parentheses or not.

Currently, I have to go through each QueryClass one by one performing the query, checking what the previous operator was, if it's part of a group, etc. and combining collections over and over until it reaches the end. This is tedious and seems like an awful way to do things. If there was a way to build these LINQ queries dynamically or perform SQL statements (what these are essential) on this collection it would be better.

Here's my query class that I'm storing the parsed strings in: