Apache Flink Scala API

import org.apache.flink.api.scala._
import org.apache.flink.api.scala.{ExecutionEnvironment, DataSet}

import org.apache.flink.api.scala._

// Create execution environment
val env = ExecutionEnvironment.getExecutionEnvironment

// Create a DataSet from a collection
val data = env.fromElements(1, 2, 3, 4, 5)

// Transform the data
val result = data
  .map(_ * 2)
  .filter(_ > 4)
  
// Execute and collect results
result.print()

object ExecutionEnvironment {
  def getExecutionEnvironment: ExecutionEnvironment
  def createLocalEnvironment(parallelism: Int = Runtime.getRuntime.availableProcessors()): ExecutionEnvironment
  def createRemoteEnvironment(host: String, port: Int, jarFiles: String*): ExecutionEnvironment
}

class ExecutionEnvironment {
  def setParallelism(parallelism: Int): Unit
  def getParallelism: Int
  def execute(): JobExecutionResult
  def execute(jobName: String): JobExecutionResult
}

class ExecutionEnvironment {
  def fromCollection[T: ClassTag : TypeInformation](data: Iterable[T]): DataSet[T]
  def fromElements[T: ClassTag : TypeInformation](data: T*): DataSet[T]
  def readTextFile(filePath: String, charsetName: String = "UTF-8"): DataSet[String]
  def generateSequence(from: Long, to: Long): DataSet[Long]
}

class DataSet[T] {
  def writeAsText(filePath: String): DataSink[T]
  def print(): DataSink[T]
  def collect(): Seq[T]
}

class DataSet[T] {
  def map[R: TypeInformation: ClassTag](fun: T => R): DataSet[R]
  def flatMap[R: TypeInformation: ClassTag](fun: T => TraversableOnce[R]): DataSet[R]  
  def filter(fun: T => Boolean): DataSet[T]
  def reduce(fun: (T, T) => T): DataSet[T]
  def distinct(): DataSet[T]
  def union(other: DataSet[T]*): DataSet[T]
}

class DataSet[T] {
  def groupBy[K: TypeInformation](fun: T => K): GroupedDataSet[T]
  def groupBy(fields: Int*): GroupedDataSet[T]
  def groupBy(firstField: String, otherFields: String*): GroupedDataSet[T]
}

class GroupedDataSet[T] {
  def reduce(fun: (T, T) => T): DataSet[T]
  def sum(field: Int): DataSet[T]
  def max(field: Int): DataSet[T] 
  def min(field: Int): DataSet[T]
  def aggregate(agg: Aggregations, field: Int): AggregateDataSet[T]
}

class DataSet[T] {
  def join[O: ClassTag](other: DataSet[O]): UnfinishedJoinOperation[T, O]
  def coGroup[O: ClassTag](other: DataSet[O]): UnfinishedCoGroupOperation[T, O]
  def cross[O: ClassTag](other: DataSet[O]): CrossDataSet[T, O]
}

class UnfinishedJoinOperation[T, O] {
  def where[K: TypeInformation](keySelector: T => K): UnfinishedJoinOperationWhere[T, O]
  def where(fields: Int*): UnfinishedJoinOperationWhere[T, O]
}

class DataSet[T] {
  def iterate(maxIterations: Int)(stepFunction: DataSet[T] => DataSet[T]): DataSet[T]
  def iterateWithTermination(maxIterations: Int)(stepFunction: DataSet[T] => (DataSet[T], DataSet[_])): DataSet[T]
  def iterateDelta[R: TypeInformation: ClassTag](
    workset: DataSet[R], 
    maxIterations: Int, 
    keyFields: Array[String]
  )(stepFunction: (DataSet[T], DataSet[R]) => (DataSet[T], DataSet[R])): DataSet[T]
}

// Implicit type information generation
implicit def createTypeInformation[T]: TypeInformation[T] = macro TypeUtils.createTypeInfo[T]

// Core type information classes
class CaseClassTypeInfo[T] extends TypeInformation[T]
class OptionTypeInfo[T] extends TypeInformation[Option[T]]
class EitherTypeInfo[A, B] extends TypeInformation[Either[A, B]]
class TryTypeInfo[T] extends TypeInformation[Try[T]]

class ExecutionEnvironment {
  def readHadoopFile[K: ClassTag : TypeInformation, V: ClassTag : TypeInformation](
    inputFormat: MapreduceInputFormat[K, V],
    keyClass: Class[K],
    valueClass: Class[V], 
    inputPath: String
  ): DataSet[(K, V)]
}

// Core execution types
class ExecutionEnvironment
class DataSet[T]
class GroupedDataSet[T] 
class CrossDataSet[T, O]
class AggregateDataSet[T]
class CoGroupDataSet[T, O]

// Configuration and results
class ExecutionConfig
class JobExecutionResult
class JobID

// Resource management
class ResourceSpec

// Type information
abstract class TypeInformation[T]
class CaseClassTypeInfo[T] extends TypeInformation[T]
class OptionTypeInfo[T] extends TypeInformation[Option[T]]
class EitherTypeInfo[A, B] extends TypeInformation[Either[A, B]]

// Serialization
abstract class TypeSerializer[T]
class CaseClassSerializer[T] extends TypeSerializer[T]

// Operators and functions  
trait MapFunction[T, O]
trait FlatMapFunction[T, O]
trait FilterFunction[T]
trait ReduceFunction[T]
trait GroupReduceFunction[T, O]
trait JoinFunction[T, O, R]
trait CoGroupFunction[T, O, R]
trait CrossFunction[T, O, R]

// Aggregation types
class Aggregations
class Order

// Join operations
class UnfinishedJoinOperation[T, O]
class UnfinishedJoinOperationWhere[T, O]  
class UnfinishedJoinOperationWhereEqual[T, O]
class JoinDataSet[T, O]

// Output types
class DataSink[T]
trait OutputFormat[T]
class TextOutputFormat[T] extends OutputFormat[T]

// Input types  
trait InputFormat[T, S]
class TextInputFormat extends InputFormat[String, FileInputSplit]

// Utilities
object DataSetUtils
class ScalaGauge[T]

// Accumulator types
trait Accumulator[V, R] 
class IntCounter extends Accumulator[Int, Int]
class LongCounter extends Accumulator[Long, Long]
class DoubleCounter extends Accumulator[Double, Double]
class Histogram extends Accumulator[Int, java.util.Map[Int, Int]]
class ListAccumulator[T] extends Accumulator[T, java.util.ArrayList[T]]
class IntMaximum extends Accumulator[Int, Int]
class IntMinimum extends Accumulator[Int, Int]
class DoubleMaximum extends Accumulator[Double, Double]
class DoubleMinimum extends Accumulator[Double, Double]

// Rich functions
trait RichFunction
abstract class RichMapFunction[T, O] extends MapFunction[T, O] with RichFunction
abstract class RichFlatMapFunction[T, O] extends FlatMapFunction[T, O] with RichFunction
abstract class RichFilterFunction[T] extends FilterFunction[T] with RichFunction
abstract class RichReduceFunction[T] extends ReduceFunction[T] with RichFunction
abstract class RichGroupReduceFunction[T, O] extends GroupReduceFunction[T, O] with RichFunction
abstract class RichMapPartitionFunction[T, O] extends MapPartitionFunction[T, O] with RichFunction

// Runtime context
trait RuntimeContext
trait BroadcastVariableInitializer[T, C]

// Configuration
class Configuration