org.eclipse.xtend.backend.common
Class EfficientLazyString

java.lang.Object
  org.eclipse.xtend.backend.common.EfficientLazyString

All Implemented Interfaces:

java.lang.CharSequence

public class EfficientLazyString
extends java.lang.Object
implements java.lang.CharSequence

This class is a "String" implementation that is optimized for efficient concatenation of arbitrary objects. It has the specialty of converting its contents to Strings lazily, i.e. only when the toString method is called. That allows slot-like behavior where an element that was added to the string can be modified later so that the modified version actually gets into the resulting string.

Another specialty is that this class can stream its contents to a Writer without the necessity of creating an intermediate string in memory.

One non-obvious benefit of consistent usage of this class is that mostly string constants from classes are stored here, and they are "interned". This can significantly decrease memory footprint and improve performance.

Author:

Arno Haase (http://www.haase-consulting.com)

Constructor Summary

EfficientLazyString()

Method Summary

char	charAt(int index)
static EfficientLazyString	createAppendedString(EfficientLazyString s, java.lang.Object o)
boolean	equals(java.lang.Object obj)
int	hashCode()
int	length()
void	makeImmutable() makes this EfficientLazyString immutable, forcing concatenation to create a new EfficientLazyString instance.
java.lang.CharSequence	subSequence(int start, int end)
java.lang.String	toString()
void	writeTo(java.io.Writer w)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

EfficientLazyString

public EfficientLazyString()

Method Detail

createAppendedString

public static EfficientLazyString createAppendedString(EfficientLazyString s,
                                                       java.lang.Object o)

makeImmutable

public void makeImmutable()

makes this EfficientLazyString immutable, forcing concatenation to create a new EfficientLazyString instance. This is done to comply with caching semantics, where the string value once returned from a function should not be modified implicitly from outside that function.

writeTo

public void writeTo(java.io.Writer w)
             throws java.io.IOException

Throws:

java.io.IOException

toString

public java.lang.String toString()

Specified by:

toString in interface java.lang.CharSequence

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

charAt

public char charAt(int index)

Specified by:

charAt in interface java.lang.CharSequence

length

public int length()

Specified by:

length in interface java.lang.CharSequence

subSequence

public java.lang.CharSequence subSequence(int start,
                                          int end)

Specified by:

subSequence in interface java.lang.CharSequence