Annotations

Annotations are in net.ririfa.yacla.annotation. Apply them to primary constructor parameters.

Annotation	Behavior
@Key("name")	Prefers the supplied document key
@Range(min, max)	Checks inclusive numeric bounds when a value is present
@NotBlank	Rejects present blank strings; null is not rejected by this annotation alone
@BlankToNull	Turns blank strings into null
@SetOf	Converts a collection to a set; an empty set becomes null
@EnumList / @EnumSet	Supported markers; enum collections also convert without them
@Loader(MyLoader::class)	Transforms a non-null raw value before built-in conversion
@Warn("message")	Logs when the processed value is null, if a logger is configured

Validate fields

import net.ririfa.yacla.annotation.NotBlank
import net.ririfa.yacla.annotation.Range

data class Credentials(
    @NotBlank val token: String,
    @Range(min = 1, max = 60) val timeoutSeconds: Int = 10
)

token is required because its type is non-null and it has no default. @NotBlank rejects whitespace-only strings. For a nullable token, use nullability and defaults deliberately; @NotBlank alone does not make it required.

Annotations validate supplied values during mapping. Omitted constructor defaults are not separately revalidated.

Custom field loader

import net.ririfa.yacla.annotation.Loader
import net.ririfa.yacla.loader.FieldLoader

class TrimLoader : FieldLoader {
    override fun load(raw: Any?): Any? = raw?.toString()?.trim()
}

data class NamedConfig(
    @Loader(TrimLoader::class) val name: String? = null
)

Custom loaders must be constructible by Kotlin reflection, for example with a no-argument constructor. Missing or null raw values do not invoke the custom loader.

Processing order

Yacla applies the custom loader, built-in conversion, @BlankToNull, @NotBlank, @Range, @SetOf, and finally @Warn. Constructor defaults and nullability are resolved afterward. A warning can therefore be emitted before a constructor default is selected.