Valin is a validation library for Kotlin, used to validate keys within any type of map.

Contains the map extension function Validate.kt/Map<K, V>.validate. It uses the following syntax:

map.validate {
validate (key, errorString) Function1
validate (key, errorString) { it == 5 }
validate (key, errorString) Function1
....
}

For each validate call, the key is used to look up a value in the map. The map value is then tested with the predicate function. If the predicate fails, the error message is included in the map of errors returned by the validate extension function. A key may be tested multiple times with different predicates and errors.

If no predicate fails, emptyMap() is returned. If at least one predicate fails, a map of keys to error is returned:

{key1=listOf(error1),
 key2=listOf(error2, error3),
 ...
 keyn=listOf(errorn)} => this is what toString() returns

For example:

val map = mapOf("name" to "Bob")

map.validate {
  validate ("name", "Name must be Joel") { x: String -> x == "Joel" }
  }

=> {name=("Name must be Joel")}

You must configure your pom.xml file using JCenter repository

<repository>
    <id>central</id>
    <name>bintray</name>
    <url>http://jcenter.bintray.com</url>
</repository>

<dependency>
  <groupId>com.joelws</groupId>
  <artifactId>valin</artifactId>
  <version>1.1</version>
</dependency>

        jcenter()
    }```  
```compile 'com.joelws:valin:1.1'```