✨ New `NotBlankString` type in `org.kotools.types` package

[LVMVRQUXL]

📝 Description

In the org.kotools.types package of the types Gradle subproject, we want to introduce the NotBlankString experimental type for representing a string that has at least one character excluding whitespaces. This type should be available for all Kotlin platforms and Java, but its orNull function shouldn't be accessible from Java, due to its non-explicit support for nullable types.

interface NotBlankString {
    val length: PositiveInteger
    
    override fun equals(other: Any?): Boolean
    override fun hashCode(): Int

    operator fun plus(other: NotBlankString): NotBlankString
    operator fun plus(other: String): NotBlankString
    
    override fun toString(): String
    
    companion object {
        fun orNull(text: String): NotBlankString? = TODO()
        fun orThrow(text: String): NotBlankString = TODO()
    }
}

Alongside this type, we want to add the NotBlankString.Companion.stringSerializer() function, in the types-kotlinx-serialization subproject, for serializing the NotBlankString type as String. This function being dedicated to the Kotlin Serialization library, it should be only available for Kotlin.

fun NotBlankString.Companion.stringSerializer(): KSerializer<NotBlankString> = TODO()

🔗 Dependencies

This issue is blocked by the following ones:

• [ ] #661

✅ Checklist

• [ ] ✨ Add the type with a private constructor.
• [ ] ✨ Add the NotBlankString.Companion.orNull(String) function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.Companion.orThrow(String) function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.length property with tests, documentation and samples.
• [ ] ✨ Override the NotBlankString.equals(Any?) function with tests, documentation and samples.
• [ ] ✨ Override the NotBlankString.hashCode() function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.plus(NotBlankString) function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.plus(String) function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.toString() function with tests, documentation and samples.
• [ ] ✨ Add the NotBlankString.Companion.stringSerializer() function with tests, documentation and samples.
• [ ] 📝 Update the unreleased changelog for this issue.