org.apache.beam.sdk.schemas.utils

Class SchemaZipFold<T>

java.lang.Object

org.apache.beam.sdk.schemas.utils.SchemaZipFold<T>

All Implemented Interfaces:

java.io.Serializable

@Experimental(value=SCHEMAS)
public abstract class SchemaZipFold<T>
extends java.lang.Object
implements java.io.Serializable

Visitor that zips schemas, and accepts pairs of fields and their types.

Values returned by `accept` are accumulated.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SchemaZipFold.Context Context referring to a current position in a schema.

Constructor Summary

Constructors

Constructor and Description
SchemaZipFold()

Method Summary

Modifier and Type	Method and Description
abstract T	accept(SchemaZipFold.Context context, java.util.Optional<Schema.Field> left, java.util.Optional<Schema.Field> right) Accepts two fields, context.parent() is always ROW.
abstract T	accept(SchemaZipFold.Context context, Schema.FieldType left, Schema.FieldType right) Accepts two components, context.parent() is always ROW, MAP, ARRAY or absent.
abstract T	accumulate(T left, T right) Accumulate two results together.
T	apply(Schema left, Schema right)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SchemaZipFold

public SchemaZipFold()

Method Detail

apply

public final T apply(Schema left,
                     Schema right)

accumulate

public abstract T accumulate(T left,
                             T right)

Accumulate two results together.

accept

public abstract T accept(SchemaZipFold.Context context,
                         Schema.FieldType left,
                         Schema.FieldType right)

Accepts two components, context.parent() is always ROW, MAP, ARRAY or absent.

accept

public abstract T accept(SchemaZipFold.Context context,
                         java.util.Optional<Schema.Field> left,
                         java.util.Optional<Schema.Field> right)

Accepts two fields, context.parent() is always ROW.