TransformationStrategies (dsiutil 2.2.2)

java.lang.Object
- it.unimi.dsi.bits.TransformationStrategies

```
public class TransformationStrategies
extends Object
```
A class providing static methods and objects that do useful things with transformation strategies.

See Also:
TransformationStrategy

Constructor Summary

Constructors
Constructor and Description

TransformationStrategies()

Constructors
Constructor and Description
`TransformationStrategies()`

Method Summary

Methods
Modifier and Type	Method and Description
`static TransformationStrategy<Long>`	`fixedLong()` A transformation from longs to bit vectors that returns a fixed-size `Long.SIZE`-bit vector.
`static <T extends BitVector> TransformationStrategy<T>`	`identity()` A trivial transformation for data already in `BitVector` form.
`static <T extends CharSequence> TransformationStrategy<T>`	`iso()` A trivial transformation from strings to bit vectors that concatenates the lower eight bits of the UTF-16 representation.
`static <T extends BitVector> TransformationStrategy<T>`	`prefixFree()` A transformation from bit vectors to bit vectors that guarantees that its results are prefix free.
`static <T extends CharSequence> TransformationStrategy<T>`	`prefixFreeIso()` A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation and completes the representation with an ASCII NUL to guarantee lexicographical ordering and prefix-freeness.
`static <T extends CharSequence> TransformationStrategy<T>`	`prefixFreeUtf16()` A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation and completes the representation with an NUL to guarantee lexicographical ordering and prefix-freeness.
`static <T extends CharSequence> TransformationStrategy<T>`	`prefixFreeUtf32()` A transformation from strings to bit vectors that decods the UTF-16 representation into a UTF-32 representation by decoding surrogate pairs, concatenates the bits of the UTF-32 representation and completes the representation with an NUL to guarantee lexicographical ordering and prefix-freeness.
`static <T extends CharSequence> TransformationStrategy<T>`	`utf16()` A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation.
`static <T extends CharSequence> TransformationStrategy<T>`	`utf32()` A transformation from strings to bit vectors that decods the UTF-16 representation into a UTF-32 representation by decoding surrogate pairs, and then concatenates the bits of the UTF-32 representation.
`static <T> Iterable<BitVector>`	`wrap(Iterable<T> iterable, TransformationStrategy<? super T> transformationStrategy)` Wraps a given iterable, returning an iterable that contains bit vectors.
`static <T> Iterator<BitVector>`	`wrap(Iterator<T> iterator, TransformationStrategy<? super T> transformationStrategy)` Wraps a given iterator, returning an iterator that emits bit vectors.
`static <T> List<BitVector>`	`wrap(List<T> list, TransformationStrategy<? super T> transformationStrategy)` Wraps a given list, returning a list that contains bit vectors.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TransformationStrategies
```
public TransformationStrategies()
```
- Method Detail
  - identity
```
public static <T extends BitVector> TransformationStrategy<T> identity()
```
    A trivial transformation for data already in BitVector form.
  - utf32
```
public static <T extends CharSequence> TransformationStrategy<T> utf32()
```
    A transformation from strings to bit vectors that decods the UTF-16 representation into a UTF-32 representation by decoding surrogate pairs, and then concatenates the bits of the UTF-32 representation.
  - prefixFreeUtf32
```
public static <T extends CharSequence> TransformationStrategy<T> prefixFreeUtf32()
```
    A transformation from strings to bit vectors that decods the UTF-16 representation into a UTF-32 representation by decoding surrogate pairs, concatenates the bits of the UTF-32 representation and completes the representation with an NUL to guarantee lexicographical ordering and prefix-freeness.
    Note that strings provided to this strategy must not contain NULs.
  - utf16
```
public static <T extends CharSequence> TransformationStrategy<T> utf16()
```
    A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation.
    Warning: bit vectors returned by this strategy are adaptors around the original string. If the string changes while the bit vector is being accessed, the results will be unpredictable.
  - prefixFreeUtf16
```
public static <T extends CharSequence> TransformationStrategy<T> prefixFreeUtf16()
```
    A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation and completes the representation with an NUL to guarantee lexicographical ordering and prefix-freeness.
    Note that strings provided to this strategy must not contain NULs.
    Warning: bit vectors returned by this strategy are adaptors around the original string. If the string changes while the bit vector is being accessed, the results will be unpredictable.
  - iso
```
public static <T extends CharSequence> TransformationStrategy<T> iso()
```
    A trivial transformation from strings to bit vectors that concatenates the lower eight bits of the UTF-16 representation.
    Note that this transformation is sensible only for strings that are known to be contain just characters in the ISO-8859-1 charset.
    Warning: bit vectors returned by this strategy are adaptors around the original string. If the string changes while the bit vector is being accessed, the results will be unpredictable.
  - prefixFreeIso
```
public static <T extends CharSequence> TransformationStrategy<T> prefixFreeIso()
```
    A trivial transformation from strings to bit vectors that concatenates the bits of the UTF-16 representation and completes the representation with an ASCII NUL to guarantee lexicographical ordering and prefix-freeness.
    Note that this transformation is sensible only for strings that are known to be contain just characters in the ISO-8859-1 charset, and that strings provided to this strategy must not contain ASCII NULs.
    Warning: bit vectors returned by this strategy are adaptors around the original string. If the string changes while the bit vector is being accessed, the results will be unpredictable.
  - wrap
```
public static <T> Iterator<BitVector> wrap(Iterator<T> iterator,
                           TransformationStrategy<? super T> transformationStrategy)
```
    Wraps a given iterator, returning an iterator that emits bit vectors.
    
    Parameters:
    iterator - an iterator.
    transformationStrategy - a strategy to transform the object returned by iterator.
    
    Returns:
    an iterator that emits the content of iterator passed through transformationStrategy.
  - wrap
```
public static <T> Iterable<BitVector> wrap(Iterable<T> iterable,
                           TransformationStrategy<? super T> transformationStrategy)
```
    Wraps a given iterable, returning an iterable that contains bit vectors.
    
    Parameters:
    iterable - an iterable.
    transformationStrategy - a strategy to transform the object contained in iterable.
    
    Returns:
    an iterable that has the content of iterable passed through transformationStrategy.
  - wrap
```
public static <T> List<BitVector> wrap(List<T> list,
                       TransformationStrategy<? super T> transformationStrategy)
```
    Wraps a given list, returning a list that contains bit vectors.
    
    Parameters:
    list - a list.
    transformationStrategy - a strategy to transform the object contained in list.
    
    Returns:
    a list that has the content of list passed through transformationStrategy.
  - prefixFree
```
public static <T extends BitVector> TransformationStrategy<T> prefixFree()
```
    A transformation from bit vectors to bit vectors that guarantees that its results are prefix free.
    More in detail, we map 0 to 10, 1 to 11, and we add a 0 at the end of all strings.
    Warning: bit vectors returned by this strategy are adaptors around the original string. If the string changes while the bit vector is being accessed, the results will be unpredictable.
  - fixedLong
```
public static TransformationStrategy<Long> fixedLong()
```
    A transformation from longs to bit vectors that returns a fixed-size Long.SIZE-bit vector. Note that the bit vectors have as first bit the most significant bit of the underlying long integer, so lexicographical and numerical order do coincide for positive numbers.

Class TransformationStrategies

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

TransformationStrategies

Method Detail

identity

utf32

prefixFreeUtf32

utf16

prefixFreeUtf16

iso

prefixFreeIso

wrap

wrap

wrap

prefixFree

fixedLong