Package org.apache.groovy.ginq.provider.collection.runtime

# Interface Window<T>

Type Parameters:
  `T` - the type of `Window` element

All Superinterfaces:
  `Queryable<T>`

public interface Window<T> extends Queryable<T>
Represents window which stores elements used by window functions

Since:
  4.0.0

- ## Nested Class Summary

  ## Nested classes/interfaces inherited from interface org.apache.groovy.ginq.provider.collection.runtime.Queryable

  `Queryable.Order<T,U extends Comparable<? super U>>`

- ## Field Summary

  ### Fields inherited from interface org.apache.groovy.ginq.provider.collection.runtime.Queryable

  `EMPTY_QUERYABLE, NULL`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `BigDecimal`
  `cumeDist()`
  Returns the cumulative distribution of a value in the window
  `Long`
  `denseRank()`
  Returns the dense rank in the window
  `<V> V`
  `firstValue(Function<? super T,? extends V> extractor)`
  Returns the first value in the window
  `default <V> V`
  `lag(Function<? super T,? extends V> extractor)`
  Returns the previous value in the window, similar to SQL's `lag()`
  `default <V> V`
  `lag(Function<? super T,? extends V> extractor, long lag)`
  Returns the previous value in the window, similar to SQL's `lag()`
  `<V> V`
  `lag(Function<? super T,? extends V> extractor, long lag, V def)`
  Returns the previous value by `lag` in the window, similar to SQL's `lag()`
  `<V> V`
  `lastValue(Function<? super T,? extends V> extractor)`
  Returns the last value in the window
  `default <V> V`
  `lead(Function<? super T,? extends V> extractor)`
  Returns the next value in the window, similar to SQL's `lead()`
  `default <V> V`
  `lead(Function<? super T,? extends V> extractor, long lead)`
  Returns the next value in the window, similar to SQL's `lead()`
  `<V> V`
  `lead(Function<? super T,? extends V> extractor, long lead, V def)`
  Returns the next value by `lead` in the window, similar to SQL's `lead()`
  `<V> V`
  `nthValue(Function<? super T,? extends V> extractor, long index)`
  Returns the nth value in the window
  `long`
  `ntile(long bucketCnt)`
  Distributes rows of an ordered window into a pre-defined number of roughly equal buckets
  `static <T, U extends Comparable<? super U>>
  Window<T>`
  `of(Tuple2<T,Long> currentRecord, Partition<Tuple2<T,Long>> partition, WindowDefinition<T,U> windowDefinition)`
  Factory method to create `Window` instance
  `BigDecimal`
  `percentRank()`
  Returns the percent rank in the window
  `Long`
  `rank()`
  Returns the rank in the window
  `long`
  `rowNumber()`
  Returns row number in the window, similar to SQL's `row_number()`

  ### Methods inherited from interface org.apache.groovy.ginq.provider.collection.runtime.Queryable

  `agg, avg, count, count, crossJoin, distinct, exists, fullHashJoin, fullJoin, groupBy, groupBy, innerHashJoin, innerJoin, intersect, leftHashJoin, leftJoin, limit, limit, max, median, min, minus, orderBy, orderBy, over, rightHashJoin, rightJoin, select, size, stdev, stdevp, stream, sum, toList, union, unionAll, var, varp, where`

- ## Method Details

  - ### of

    static <T, U extends Comparable<? super U>> Window<T> of(Tuple2<T,Long> currentRecord, Partition<Tuple2<T,Long>> partition, WindowDefinition<T,U> windowDefinition)
    Factory method to create `Window` instance
    Type Parameters:
      `T` - the type of `Window` element
      `U` - the type of field to sort
    Parameters:
      `currentRecord` - current record
      `partition` - the partition where the window is constructed
      `windowDefinition` - window definition
    Returns:
      the `Window` instance
    Since:
      4.0.0

  - ### rowNumber

    long rowNumber()
    Returns row number in the window, similar to SQL's `row_number()`
    Returns:
      the row number
    Since:
      4.0.0

  - ### lead

    default <V> V lead(Function<? super T,? extends V> extractor)
    Returns the next value in the window, similar to SQL's `lead()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
    Returns:
      the next value
    Since:
      4.0.0

  - ### lead

    default <V> V lead(Function<? super T,? extends V> extractor, long lead)
    Returns the next value in the window, similar to SQL's `lead()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
      `lead` - the offset
    Returns:
      the next value
    Since:
      4.0.0

  - ### lead

    <V> V lead(Function<? super T,? extends V> extractor, long lead, V def)
    Returns the next value by `lead` in the window, similar to SQL's `lead()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
      `lead` - the offset
      `def` - the default value
    Returns:
      the next value by `lead`
    Since:
      4.0.0

  - ### lag

    default <V> V lag(Function<? super T,? extends V> extractor)
    Returns the previous value in the window, similar to SQL's `lag()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
    Returns:
      the previous value
    Since:
      4.0.0

  - ### lag

    default <V> V lag(Function<? super T,? extends V> extractor, long lag)
    Returns the previous value in the window, similar to SQL's `lag()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
      `lag` - the offset
    Returns:
      the previous value
    Since:
      4.0.0

  - ### lag

    <V> V lag(Function<? super T,? extends V> extractor, long lag, V def)
    Returns the previous value by `lag` in the window, similar to SQL's `lag()`
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
      `lag` - the offset
      `def` - the default value
    Returns:
      the previous value by `lag`
    Since:
      4.0.0

  - ### firstValue

    <V> V firstValue(Function<? super T,? extends V> extractor)
    Returns the first value in the window
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
    Returns:
      the first value
    Since:
      4.0.0

  - ### lastValue

    <V> V lastValue(Function<? super T,? extends V> extractor)
    Returns the last value in the window
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
    Returns:
      the last value
    Since:
      4.0.0

  - ### nthValue

    <V> V nthValue(Function<? super T,? extends V> extractor, long index)
    Returns the nth value in the window
    Type Parameters:
      `V` - the type of field
    Parameters:
      `extractor` - field extractor
      `index` - index for value to fetch, starting with `0`
    Returns:
      the nth value
    Since:
      4.0.0

  - ### rank

    Long rank()
    Returns the rank in the window
    Returns:
      the rank
    Since:
      4.0.0

  - ### denseRank

    Long denseRank()
    Returns the dense rank in the window
    Returns:
      the dense rank
    Since:
      4.0.0

  - ### percentRank

    BigDecimal percentRank()
    Returns the percent rank in the window
    Returns:
      the percent rank
    Since:
      4.0.0

  - ### cumeDist

    BigDecimal cumeDist()
    Returns the cumulative distribution of a value in the window
    Returns:
      the cumulative distribution of a value
    Since:
      4.0.0

  - ### ntile

    long ntile(long bucketCnt)
    Distributes rows of an ordered window into a pre-defined number of roughly equal buckets
    Parameters:
      `bucketCnt` - bucket count
    Returns:
      bucket index starting with `0`
    Since:
      4.0.0