uk.ac.starlink.table

## Class SelectorStarTable

- java.lang.Object
- - uk.ac.starlink.table.WrapperStarTable
  - - uk.ac.starlink.table.SelectorStarTable

- All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, StarTable

      public abstract class SelectorStarTable
      extends WrapperStarTable

  Sequential wrapper table which selects only certain rows of its base table. No random access is provided, and the row sequence evaluates the abstract `isIncluded(uk.ac.starlink.table.RowSequence)` method for each row of the base table as it is iterated over.
  Since:
    11 Feb 2005

- - ### Field Summary

    - ### Fields inherited from class uk.ac.starlink.table.WrapperStarTable

      `baseTable`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SelectorStarTable(StarTable baseTable)` Constructor.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `java.lang.Object` | `getCell(int icol)`
    `java.lang.Object[]` | `getRow()`
    `RowAccess` | `getRowAccess()` Returns an object which can provide random access to this table's data, if random access is implemented.
    `long` | `getRowCount()` Returns -1 (length unknown).
    `RowSequence` | `getRowSequence()` Returns an object which can iterate over all the rows in the table sequentially.
    `RowSplittable` | `getRowSplittable()` Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.
    `abstract boolean` | `isIncluded(RowSequence baseSeq)` Evaluated to determine whether rows of the base table are included in this one.
    `boolean` | `isRandom()` Returns false.

    - ### Methods inherited from class uk.ac.starlink.table.WrapperStarTable

      `checkedLongToInt, close, getBaseTable, getCell, getColumnAuxDataInfos, getColumnCount, getColumnInfo, getName, getParameterByName, getParameters, getRow, getURL, setName, setParameter, setURL, toString`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### SelectorStarTable

          public SelectorStarTable(StarTable baseTable)

      Constructor.
      Parameters:
        `baseTable` - table on which this is based

  - ### Method Detail

    - #### isIncluded

          public abstract boolean isIncluded(RowSequence baseSeq)
                                      throws java.io.IOException

      Evaluated to determine whether rows of the base table are included in this one.
      Parameters:
        `baseSeq` - row sequence of the base table
      Returns:
        true iff the current row of `baseSeq` is to be included
      Throws:
        `java.io.IOException`

    - #### isRandom

          public boolean isRandom()

      Returns false.
      Specified by:
        `isRandom` in interface `StarTable`
      Overrides:
        `isRandom` in class `WrapperStarTable`
      Returns:
        `true` if table random access methods are available

    - #### getRowCount

          public long getRowCount()

      Returns -1 (length unknown).
      Specified by:
        `getRowCount` in interface `StarTable`
      Overrides:
        `getRowCount` in class `WrapperStarTable`
      Returns:
        the number of rows, or -1

    - #### getRow

          public java.lang.Object[] getRow()

    - #### getCell

          public java.lang.Object getCell(int icol)

    - #### getRowSequence

          public RowSequence getRowSequence()
                                     throws java.io.IOException

      Description copied from interface: `StarTable`
      Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
      Specified by:
        `getRowSequence` in interface `StarTable`
      Overrides:
        `getRowSequence` in class `WrapperStarTable`
      Returns:
        new RowSequence
      Throws:
        `java.io.IOException` - if there is an error providing access

    - #### getRowSplittable

          public RowSplittable getRowSplittable()
                                         throws java.io.IOException

      Description copied from interface: `StarTable`
      Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.

      The return value must be non-null, and may provide splitting arrangements specially appropriate for the implementation. If this table 'wraps' an upstream table, it is usually best to base the implementation on calls to the the upstream `getRowSplittable` method, so that upstream policy about how to divide up the table is respected. However, implementations without special requirements may return `Tables.getDefaultRowSplittable``(this)`.

      Specified by:
        `getRowSplittable` in interface `StarTable`
      Overrides:
        `getRowSplittable` in class `WrapperStarTable`
      Returns:
        new RowSplittable
      Throws:
        `java.io.IOException`
      See Also:
        `RowRunner`

    - #### getRowAccess

          public RowAccess getRowAccess()

      Description copied from interface: `StarTable`
      Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.
      Specified by:
        `getRowAccess` in interface `StarTable`
      Overrides:
        `getRowAccess` in class `WrapperStarTable`
      Returns:
        new RowAccess