Skip to content

Maintenance fork of the Xeger Java library for generating strings according to a regexp

License

Notifications You must be signed in to change notification settings

agarciadom/xeger

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

41 Commits
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

Java CI

This is a maintenance fork of the Xeger library. It is a Java library for generating strings that match a specific regular expression. The original version of Xeger is available from this address, but development seems to have stopped:

http://code.google.com/p/xeger/

The objective of this fork is to simply maintain Xeger, fixing the reported bugs as they come. Pull requests are welcome, though :-).

For reference, I have copied several useful sections of the original website below.

Introduction

Think of it as the opposite of regular expression matchers. This library allows you to generate text that is guaranteed to match a regular expression passed in.

Let's take the regular expression: [ab]{4,6}c Using Xeger, you can now generate Strings matching this pattern like this:

String regex = "[ab]{4,6}c";
Xeger generator = new Xeger(regex);
String result = generator.generate();
assert result.matches(regex);

Limitations

Xeger does not support all valid Java regular expressions. The full set of what is defined here and is summarized below. Future versions might support a more complete set, in case of popular demand.

regexp  ::=     unionexp                
|                       
unionexp        ::=     interexp | unionexp     (union) 
|       interexp                
interexp        ::=     concatexp & interexp    (intersection)  [OPTIONAL]
|       concatexp               
concatexp       ::=     repeatexp concatexp     (concatenation) 
|       repeatexp               
repeatexp       ::=     repeatexp ?     (zero or one occurrence)        
|       repeatexp *     (zero or more occurrences)      
|       repeatexp +     (one or more occurrences)       
|       repeatexp {n}   (n occurrences) 
|       repeatexp {n,}  (n or more occurrences) 
|       repeatexp {n,m} (n to m occurrences, including both)    
|       complexp                
complexp        ::=     ~ complexp      (complement)    [OPTIONAL]
|       charclassexp            
charclassexp    ::=     [ charclasses ] (character class)       
|       [^ charclasses ]        (negated character class)       
|       simpleexp               
charclasses     ::=     charclass charclasses           
|       charclass               
charclass       ::=     charexp - charexp       (character range, including end-points) 
|       charexp         
simpleexp       ::=     charexp         
|       .       (any single character)  
|       #       (the empty language)    [OPTIONAL]
|       @       (any string)    [OPTIONAL]
|       " <Unicode string without double-quotes> "      (a string)      
|       ( )     (the empty string)      
|       ( unionexp )    (precedence override)   
|       < <identifier> >        (named automaton)       [OPTIONAL]
|       <n-m>   (numerical interval)    [OPTIONAL]
charexp ::=     <Unicode character>     (a single non-reserved character)       
|       \ <Unicode character>   (a single character)

Maven repository

A binary build of this library is available from the GitHub Package Registry:

<repositories>
  <repository>
    <id>github</id>
    <name>GitHub agarciadom Apache Maven Packages</name>
    <url>https://maven.pkg.github.com/agarciadom/xeger</url>
  </repository>
</repositories>

Please note that you will need to authenticate to GitHub to access this repository, as documented here.

About

Maintenance fork of the Xeger Java library for generating strings according to a regexp

Resources

License

Stars

Watchers

Forks

Packages

 
 
 

Contributors 4

  •  
  •  
  •  
  •  

Languages