Kotlin Code Smell 29 - Regular Expression Abusers
From Spaghetti Code to Readable Magic
Table of contents
RegEx is a wonderful tool, we should use them carefully and not look smart.
Problem
Readability
Maintainability
Testability
Intention Revealing
Solution
Use regular expressions just for string validation.
If you need to manipulate objects, don't make them strings.
Sample Code
Wrong
val regex = "^\\+(?:[0-9a-zA-Z][– -]?){6,14}[0-9a-zA-Z]$".toRegex()
Right
val prefix = """\+"""
val digit = "[0-9a-zA-Z]"
val space = "[– -]"
val phoneRegex = "^$prefix(?:$digit$space?){6,14}$digit$".toRegex()
Conclusion
Regular expressions are a great tool for string validation. We must use them in a declarative way and just for strings.
Names are very important to understand pattern meanings.
If we need to manipulate objects or hierarchies, we should do it in an object way.
Unless we have a conclusive benchmark of impressive performance improvement.