a lot of improvements in language codes

resources/src/commonMain/kotlin/StringResource.kt

@@ -2,6 +2,19 @@ package dev.inmo.micro_utils.strings
 
 import dev.inmo.micro_utils.language_codes.IetfLanguageCode
 
+/**
+ * Use this class as a type of your strings object fields. For example:
+ *
+ * ```kotlin
+ * object Strings {
+ *     val someResource: StringResource
+ * }
+ * ```
+ *
+ * Use [buildStringResource] for useful creation of string resource
+ *
+ * @see buildStringResource
+ */
 class StringResource(
     val default: String,
     val map: Map<IetfLanguageCode, Lazy<String>>
@@ -14,14 +27,24 @@ class StringResource(
         infix fun IetfLanguageCode.variant(value: Lazy<String>) {
             map[this] = value
         }
+        infix fun IetfLanguageCode.variant(value: () -> String) = this variant lazy(value)
         infix fun IetfLanguageCode.variant(value: String) = this variant lazyOf(value)
+
+
         infix fun String.variant(value: Lazy<String>) = IetfLanguageCode(this) variant value
+        infix fun String.variant(value: () -> String) = IetfLanguageCode(this) variant lazy(value)
         infix fun String.variant(value: String) = this variant lazyOf(value)
 
         fun build() = StringResource(default, map.toMap())
     }
 
-    fun translation(languageCode: IetfLanguageCode): String = (map[languageCode] ?: map[IetfLanguageCode(languageCode.withoutDialect)]) ?.value ?: default
+    fun translation(languageCode: IetfLanguageCode): String {
+        map[languageCode] ?.let { return it.value }
+
+        return languageCode.parentLang ?.let {
+            map[it] ?.value
+        } ?: default
+    }
 }
 
 inline fun buildStringResource(