All Implemented Interfaces:
NamedWriteable, Writeable, Resolvable, EvaluatorMapper, ConvertFunction
Direct Known Subclasses:
FoldablesConvertFunction, ToAggregateMetricDouble, ToBoolean, ToCartesianPoint, ToCartesianShape, ToDateNanos, ToDatetime, ToDegrees, ToDenseVector, ToDouble, ToGeohash, ToGeohex, ToGeoPoint, ToGeoShape, ToGeotile, ToInteger, ToIpLeadingZerosDecimal, ToIpLeadingZerosOctal, ToIpLeadingZerosRejected, ToLong, ToRadians, ToString, ToUnsignedLong, ToVersion

public abstract class AbstractConvertFunction extends UnaryScalarFunction implements ConvertFunction
Base class for functions that converts a field into a function-specific type.

We have a guide for writing these in the javadoc for org.elasticsearch.xpack.esql.expression.function.scalar.