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kantan.regex is a library for extracting useful types from regular expression matches written in the Scala programming language.

Getting started

kantan.regex is currently available for Scala 2.12 and 2.13.

The current version is 0.5.1, which can be added to your project with one or more of the following line(s) in your SBT build file:

// Core library, included automatically if any other module is imported.
libraryDependencies += "com.nrinaudo" %% "kantan.regex" % "0.5.1"

// Java 8 date and time instances.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-java8" % "0.5.1"

// Provides generic instance derivation through shapeless.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-generic" % "0.5.1"

// Provides scalaz type class instances.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-scalaz" % "0.5.1"

// Provides cats type class instances.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-cats" % "0.5.1"

// Provides refined decoders.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-refined" % "0.5.1"

// Provides enumeratum decoders.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-enumeratum" % "0.5.1"

// Provides libra decoders.
libraryDependencies += "com.nrinaudo" %% "kantan.regex-libra" % "0.5.1"


Regular expressions, for all their flaws, are still extremely useful to extract content from raw strings. Scala, unfortunately, doesn’t do much with that - the regex library is great for checking matches, but not extracting well-typed data from them.

Kantan.regex is meant to fill that void - and nothing else. By that, I mean that if you need to use regular expressions as predicates (does a string match a certain pattern?), kantan.regex is absolutely not the right tool for the job. If, on the other hand, you need to extract bits of strings as custom, composite types, in a safe way and checked at compile time, then it might just be.


The following tutorials are available: