com.google.javascript.jscomp

Class RandomNameGenerator

java.lang.Object

com.google.javascript.jscomp.RandomNameGenerator

@GwtIncompatible(value="java.util.Collections.shuffle, com.google.common.hash.Hasher, com.google.common.hash.Hashing")
public final class RandomNameGenerator
extends java.lang.Object

A class for generating unique, randomized JavaScript variable/property names.

Unlike NameGenerator, names do not follow a predictable sequence such as a, b, ... z, aa, ab, ..., az, ba, ... but instead they are random, based on an external random seed. We do partially compromise for efficiency in that

• Generated names will have the same length as they would with NameGenerator
• We don't use a completely different alphabet for each name prefix, but instead choose among a few with a predictable formula.

More precisely:

• We compute a random shuffle of the alphabet for "first characters", and a small number of random shuffles of the alphabet for "non-first characters". Then we do a typical number-to-text conversion of a name's "index", where the alphabet for digits is not just 0 to 9. The least significant digit comes first.
• We represent each digit using an appropriate alphabet. If it's not the first character of the name (i.e. not the least significant one, or there is a constant prefix) then we have several appropriate alphabets to choose from; we choose one based a hash of the previous digits of this name.

This class is not thread safe.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RandomNameGenerator(java.util.Random random)

Method Summary

Modifier and Type	Method and Description
com.google.javascript.jscomp.NameGenerator	clone(java.util.Set<java.lang.String> reservedNames, java.lang.String prefix, char[] reservedCharacters) Returns a clone of this NameGenerator, reconfigured and reset.
java.lang.String	generateNextName() Generates the next short name.
void	reset(java.util.Set<java.lang.String> reservedNames, java.lang.String prefix, char[] reservedCharacters) Reconfigures this NameGenerator, and resets it to the initial state.
void	reset(java.util.Set<java.lang.String> reservedNames, java.lang.String prefix, char[] reservedFirstCharacters, char[] reservedNonFirstCharacters) Reconfigures this NameGenerator, and resets it to the initial state.

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomNameGenerator

public RandomNameGenerator(java.util.Random random)

Method Detail

reset

public void reset(java.util.Set<java.lang.String> reservedNames,
                  java.lang.String prefix,
                  @Nullable
                  char[] reservedCharacters)

Reconfigures this NameGenerator, and resets it to the initial state.

Parameters:

reservedNames - set of names that are reserved; generated names will not include these names. This set is referenced rather than copied, so changes to the set will be reflected in how names are generated.

prefix - all generated names begin with this prefix.

reservedCharacters - If specified these characters won't be used in generated names

reset

public void reset(java.util.Set<java.lang.String> reservedNames,
                  java.lang.String prefix,
                  @Nullable
                  char[] reservedFirstCharacters,
                  @Nullable
                  char[] reservedNonFirstCharacters)

Reconfigures this NameGenerator, and resets it to the initial state.

Parameters:

reservedNames - set of names that are reserved; generated names will not include these names. This set is referenced rather than copied, so changes to the set will be reflected in how names are generated.

prefix - all generated names begin with this prefix.

reservedFirstCharacters - If specified these characters won't be used as the first character in generated names

reservedNonFirstCharacters - If specified these characters won't be used for characters (after the first) in generated names

clone

public com.google.javascript.jscomp.NameGenerator clone(java.util.Set<java.lang.String> reservedNames,
                                                        java.lang.String prefix,
                                                        @Nullable
                                                        char[] reservedCharacters)

Returns a clone of this NameGenerator, reconfigured and reset.

generateNextName

public java.lang.String generateNextName()

Generates the next short name.

This generates names of increasing length. To minimize output size, therefore, it's good to call it for the most used symbols first.