Package com.saxonica.ee.optim

## Class SearchableValue

- java.lang.Object
- - com.saxonica.ee.optim.SearchableValue

- All Implemented Interfaces:
    `GroundedValue`, `Sequence`
  Direct Known Subclasses:
    `IndexedValue`

      public abstract class SearchableValue
      extends java.lang.Object
      implements GroundedValue

  A sequence that is held in a form that permits rapid searching, typically by use of indexes. This is an abstract class with several implementations

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected int` | `end` |
    `protected Item[]` | `value` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `SearchableValue()` |

  - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `effectiveBooleanValue()` | Get the effective boolean value of this sequence
    `abstract SequenceIterator` | `findItems​(Expression use, SequenceIterator values, boolean convertUntypedToOther, boolean firstOnly, AtomicComparer comparer, XPathContext context)` | Retrieve items that match a given index value
    `int` | `getLength()` | Get the length of the sequence
    `java.lang.String` | `getStringValue()` | Get the string value of this sequence.
    `java.lang.CharSequence` | `getStringValueCS()` | Get the string value of this sequence.
    `Item` | `head()` | Get the first item in the sequence.
    `Item` | `itemAt​(int n)` | Get the n'th item in the sequence (starting from 0).
    `UnfailingIterator` | `iterate()` | Return an Iterator to iterate over the values of a sequence.
    `static SearchableValue` | `makeSearchableValue​(SequenceIterator iter)` |
    `GroundedValue` | `reduce()` | Reduce the sequence to its simplest form.
    `GroundedValue` | `subsequence​(int start, int length)` | Get a subsequence of the value

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

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

    - ### Methods inherited from interface net.sf.saxon.om.GroundedValue

      `asIterable, concatenate, containsNode, materialize, toShortString`

    - ### Methods inherited from interface net.sf.saxon.om.Sequence

      `makeRepeatable`

- - ### Field Detail

    - #### value

          protected Item[] value

    - #### end

          protected int end

  - ### Constructor Detail

    - #### SearchableValue

          public SearchableValue()

  - ### Method Detail

    - #### makeSearchableValue

          public static SearchableValue makeSearchableValue​(SequenceIterator iter)
                                                     throws XPathException

      Throws:
        `XPathException`

    - #### iterate

          public UnfailingIterator iterate()

      Return an Iterator to iterate over the values of a sequence. The value of every expression can be regarded as a sequence, so this method is supported for all expressions. This default implementation handles iteration for expressions that return singleton values: for non-singleton expressions, the subclass must provide its own implementation.
      Specified by:
        `iterate` in interface `GroundedValue`
      Specified by:
        `iterate` in interface `Sequence`
      Returns:
        a SequenceIterator that can be used to iterate over the result of the expression

    - #### itemAt

          public Item itemAt​(int n)

      Get the n'th item in the sequence (starting from 0). This is defined for all Values, but its real benefits come for a sequence Value stored extensionally (or for a MemoClosure, once all the values have been read)
      Specified by:
        `itemAt` in interface `GroundedValue`
      Parameters:
        `n` - position of the required item, counting from zero.
      Returns:
        the n'th item in the sequence, where the first item in the sequence is numbered zero. If n is negative or >= the length of the sequence, returns null.

    - #### getLength

          public int getLength()

      Get the length of the sequence
      Specified by:
        `getLength` in interface `GroundedValue`
      Returns:
        the number of items in the sequence. Note that for a single item, including a map or array, the result is always 1 (one).

    - #### findItems

          public abstract SequenceIterator findItems​(Expression use,
                                                     SequenceIterator values,
                                                     boolean convertUntypedToOther,
                                                     boolean firstOnly,
                                                     AtomicComparer comparer,
                                                     XPathContext context)
                                              throws XPathException

      Retrieve items that match a given index value
      Parameters:
        `use` - the expression whose value is to be matched
        `values` - the set of values to be found
        `convertUntypedToOther` - true if untypedAtomic values are to be converted to the type of the other operand
        `firstOnly` - true if only the first matching item is required
        `comparer` - AtomicComparer used to compare values for equality (encapsulates a collation if necessary)
        `context` - the dynamic evaluation context @return an iterator over the items that match the specified values
      Returns:
        an iterator over the items that matched
      Throws:
        `XPathException` - if an error occurs

    - #### subsequence

          public GroundedValue subsequence​(int start,
                                           int length)

      Get a subsequence of the value
      Specified by:
        `subsequence` in interface `GroundedValue`
      Parameters:
        `start` - the index of the first item to be included in the result, counting from zero. A negative value is taken as zero. If the value is beyond the end of the sequence, an empty sequence is returned
        `length` - the number of items to be included in the result. Specify Integer.MAX_VALUE to get the subsequence up to the end of the base sequence. If the value is negative, an empty sequence is returned. If the value goes off the end of the sequence, the result returns items up to the end of the sequence
      Returns:
        the required subsequence. If min is

    - #### effectiveBooleanValue

          public boolean effectiveBooleanValue()
                                        throws XPathException

      Description copied from interface: `GroundedValue`
      Get the effective boolean value of this sequence
      Specified by:
        `effectiveBooleanValue` in interface `GroundedValue`
      Returns:
        the effective boolean value
      Throws:
        `XPathException` - if the sequence has no effective boolean value (for example a sequence of two integers)

    - #### getStringValue

          public java.lang.String getStringValue()
                                          throws XPathException

      Description copied from interface: `GroundedValue`
      Get the string value of this sequence. The string value of an item is the result of applying the string() function. The string value of a sequence is the space-separated result of applying the string-join() function using a single space as the separator
      Specified by:
        `getStringValue` in interface `GroundedValue`
      Returns:
        the string value of the sequence.
      Throws:
        `XPathException` - if the sequence contains items that have no string value (for example, function items)

    - #### getStringValueCS

          public java.lang.CharSequence getStringValueCS()
                                                  throws XPathException

      Description copied from interface: `GroundedValue`
      Get the string value of this sequence. The string value of an item is the result of applying the string() function. The string value of a sequence is the space-separated result of applying the string-join() function using a single space as the separator
      Specified by:
        `getStringValueCS` in interface `GroundedValue`
      Returns:
        the string value of the sequence.
      Throws:
        `XPathException` - if the sequence contains items that have no string value (for example, function items)

    - #### head

          public Item head()

      Get the first item in the sequence.
      Specified by:
        `head` in interface `GroundedValue`
      Specified by:
        `head` in interface `Sequence`
      Returns:
        the first item in the sequence if there is one, or null if the sequence is empty

    - #### reduce

          public GroundedValue reduce()

      Reduce the sequence to its simplest form. If the value is an empty sequence, the result will be EmptySequence.getInstance(). If the value is a single atomic value, the result will be an instance of AtomicValue. If the value is a single item of any other kind, the result will be an instance of SingletonItem. Otherwise, the result will typically be unchanged.
      Specified by:
        `reduce` in interface `GroundedValue`
      Returns:
        the simplified sequence