RegExp (Google Web Toolkit Javadoc)

java.lang.Object
- com.google.gwt.regexp.shared.RegExp

```
public class RegExp
extends java.lang.Object
```
A class for regular expressions with features like Javascript's RegExp, plus Javascript String's replace and split methods (which can take a RegExp parameter). The pure Java implementation (for server-side use) uses Java's Pattern class, unavailable under GWT. The super-sourced GWT implementation simply calls on to the native Javascript classes.
There are a few small incompatibilities between the two implementations. Java-specific constructs in the regular expression syntax (e.g. [a-z&&[^bc]], (?<=foo), \A, \Q) work only in the pure Java implementation, not the GWT implementation, and are not rejected by either. Also, the Javascript-specific constructs $` and $' in the replacement expression work only in the GWT implementation, not the pure Java implementation, which rejects them.

Method Summary

Methods
Modifier and Type	Method and Description
`static RegExp`	`compile(java.lang.String pattern)` Creates a regular expression object from a pattern with no flags.
`static RegExp`	`compile(java.lang.String pattern, java.lang.String flags)` Creates a regular expression object from a pattern using the given flags.
`MatchResult`	`exec(java.lang.String input)` Applies the regular expression to the given string.
`boolean`	`getGlobal()` Returns whether the regular expression captures all occurrences of the pattern.
`boolean`	`getIgnoreCase()` Returns whether the regular expression ignores case.
`int`	`getLastIndex()` Returns the zero-based position at which to start the next match.
`boolean`	`getMultiline()` Returns whether '$' and '^' match line returns ('\n' and '\r') in addition to the beginning or end of the string.
`java.lang.String`	`getSource()` Returns the pattern string of the regular expression.
`java.lang.String`	`replace(java.lang.String input, java.lang.String replacement)` Returns the input string with the part(s) matching the regular expression replaced with the replacement string.
`void`	`setLastIndex(int lastIndex)` Sets the zero-based position at which to start the next match.
`SplitResult`	`split(java.lang.String input)` Splits the input string around matches of the regular expression.
`SplitResult`	`split(java.lang.String input, int limit)` Splits the input string around matches of the regular expression.
`boolean`	`test(java.lang.String input)` Determines if the regular expression matches the given string.

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

- Method Detail
  - compile
```
public static RegExp compile(java.lang.String pattern)
```
    Creates a regular expression object from a pattern with no flags.
    
    Parameters:
    pattern - the Javascript regular expression pattern to compile
    
    Returns:
    a new regular expression
    
    Throws:
    
    java.lang.RuntimeException - if the pattern is invalid
  - compile
```
public static RegExp compile(java.lang.String pattern,
             java.lang.String flags)
```
    Creates a regular expression object from a pattern using the given flags.
    
    Parameters:
    pattern - the Javascript regular expression pattern to compile
    flags - the flags string, containing at most one occurrence of 'g' (getGlobal()), 'i' (getIgnoreCase()), or 'm' (getMultiline()).
    
    Returns:
    a new regular expression
    
    Throws:
    
    java.lang.RuntimeException - if the pattern or the flags are invalid
  - exec
```
public MatchResult exec(java.lang.String input)
```
    Applies the regular expression to the given string. This call affects the value returned by getLastIndex() if the global flag is set.
    
    Parameters:
    input - the string to apply the regular expression to
    
    Returns:
    a match result if the string matches, else null
  - getGlobal
```
public boolean getGlobal()
```
    Returns whether the regular expression captures all occurrences of the pattern.
  - getIgnoreCase
```
public boolean getIgnoreCase()
```
    Returns whether the regular expression ignores case.
  - getLastIndex
```
public int getLastIndex()
```
    Returns the zero-based position at which to start the next match. The return value is not defined if the global flag is not set. After a call to exec(String) or test(String), this method returns the next position following the most recent match.
    
    See Also:
    getGlobal()
  - getMultiline
```
public boolean getMultiline()
```
    Returns whether '$' and '^' match line returns ('\n' and '\r') in addition to the beginning or end of the string.
  - getSource
```
public java.lang.String getSource()
```
    Returns the pattern string of the regular expression.
  - replace
```
public java.lang.String replace(java.lang.String input,
                       java.lang.String replacement)
```
    Returns the input string with the part(s) matching the regular expression replaced with the replacement string. If the global flag is set, replaces all matches of the regular expression. Otherwise, replaces the first match of the regular expression. As per Javascript semantics, backslashes in the replacement string get no special treatment, but the replacement string can use the following special patterns:
    - $1, $2, ... $99 - inserts the n'th group matched by the regular expression.
    - $& - inserts the entire string matched by the regular expression.
    - $$ - inserts a $.
    Note: $` and $' are *not* supported in the pure Java implementation, and throw an exception.
    Parameters:
    input - the string in which the regular expression is to be searched.
    replacement - the replacement string.
    
    Returns:
    the input string with the regular expression replaced by the replacement string.
    
    Throws:
    
    java.lang.RuntimeException - if replacement is invalid
  - setLastIndex
```
public void setLastIndex(int lastIndex)
```
    Sets the zero-based position at which to start the next match.
  - split
```
public SplitResult split(java.lang.String input)
```
    Splits the input string around matches of the regular expression. If the regular expression is completely empty, splits the input string into its constituent characters. If the regular expression is not empty but matches an empty string, the results are not well defined.
    
    Parameters:
    input - the string to be split.
    
    Returns:
    the strings split off, any of which may be empty.
  - split
```
public SplitResult split(java.lang.String input,
                int limit)
```
    Splits the input string around matches of the regular expression. If the regular expression is completely empty, splits the input string into its constituent characters. If the regular expression is not empty but matches an empty string, the results are not well defined. Note: There are some browser inconsistencies with this implementation, as it is delegated to the browser, and no browser follows the spec completely. A major difference is that IE will exclude empty strings in the result.
    
    Parameters:
    input - the string to be split.
    limit - the maximum number of strings to split off and return, ignoring the rest of the input string. If negative, there is no limit.
    
    Returns:
    the strings split off, any of which may be empty.
  - test
```
public boolean test(java.lang.String input)
```
    Determines if the regular expression matches the given string. This call affects the value returned by getLastIndex() if the global flag is set. Equivalent to: exec(input) != null
    
    Parameters:
    input - the string to apply the regular expression to
    
    Returns:
    whether the regular expression matches the given string.

Class RegExp

Method Summary

Methods inherited from class java.lang.Object

Method Detail

compile

compile

exec

getGlobal

getIgnoreCase

getLastIndex

getMultiline

getSource

replace

setLastIndex

split

split

test