Pattern

java.lang.Object
- jfun.parsec.pattern.Pattern

All Implemented Interfaces:

java.io.Serializable
```
public abstract class Pattern
extends java.lang.Object
implements java.io.Serializable
```
A Pattern object encapsulates an algorithm to recognize certain string pattern. When fed with a character range, a Pattern object either fails to match, or matches with the match length returned.
Pattern object is used for terminal level parsers. A Pattern differs from a Parser in that it does not return object, and it simply reports mismatch whenenver fails. While Parser cannot be implemented directly, Pattern can be implemented directly by user code.

Author:

Ben Yu Dec 16, 2004

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

static int MISMATCH
returned by match() method when match fails.

Fields
Modifier and Type	Field and Description
`static int`	`MISMATCH` returned by match() method when match fails.

Constructor Summary

Constructors
Constructor and Description

Pattern()

Constructors
Constructor and Description
`Pattern()`

Method Summary

Methods
Modifier and Type	Method and Description
`Pattern`	`ifelse(Pattern yes, Pattern no)` If this pattern matches, match the remaining input against Pattern object yes.
`Pattern`	`many()` Matches this pattern for 0 or more times.
`Pattern`	`many(int min)` Matches this pattern for at least min times.
`Pattern`	`many1()` Matches this pattern for 1 or more times.
`abstract int`	`match(java.lang.CharSequence src, int len, int from)` The actual length of the pattern string is len - from.
`Pattern`	`not()` If this pattern matches, return mismatch.
`Pattern`	`optional()` Match with 0 length even if this pattern mismatches.
`Pattern`	`peek()` Matches with match length 0 if this Pattern object matches.
`Pattern`	`repeat(int n)` Matches the input against this pattern for n times.
`Pattern`	`seq(Pattern p2)` First matches this pattern.
`Pattern`	`some(int max)` Matches this pattern for up to max times.
`Pattern`	`some(int min, int max)` Matches this pattern for at least min times and at most max times.

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

- Field Detail
  - MISMATCH
```
public static final int MISMATCH
```
    returned by match() method when match fails.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - Pattern
```
public Pattern()
```
- Method Detail
  - match
```
public abstract int match(java.lang.CharSequence src,
        int len,
        int from)
```
    The actual length of the pattern string is len - from.
    
    Parameters:
    src - the source string.
    len - the length of the sequence. NOTE: the range is [from, len], not [from,from+len].
    from - the starting index in the sequence.
    
    Returns:
    the number of characters matched. MISMATCH otherwise.
  - seq
```
public final Pattern seq(Pattern p2)
```
    First matches this pattern. If succeed, match the remaining input against Pattern p2. Fails if either this or p2 fails. Succeed with the entire match length, which is the sum of the match length of this and p2.
    
    Parameters:
    p2 - the next Pattern object to match.
    
    Returns:
    the new Pattern object.
  - optional
```
public final Pattern optional()
```
    Match with 0 length even if this pattern mismatches.
    
    Returns:
    the new Pattern object.
  - many
```
public final Pattern many()
```
    Matches this pattern for 0 or more times. Return the total match length.
    
    Returns:
    the new Pattern object.
  - many
```
public final Pattern many(int min)
```
    Matches this pattern for at least min times. Return the total match length.
    
    Parameters:
    min - the minimal number of times to match.
    
    Returns:
    the new Pattern object.
  - many1
```
public final Pattern many1()
```
    Matches this pattern for 1 or more times. Return the total match length.
    
    Returns:
    the new Pattern object.
  - some
```
public final Pattern some(int max)
```
    Matches this pattern for up to max times. Return the total match length.
    
    Parameters:
    max - the maximal number of times to match.
    
    Returns:
    the new Pattern object.
  - some
```
public final Pattern some(int min,
           int max)
```
    Matches this pattern for at least min times and at most max times. Return the total match length.
    
    Parameters:
    min - the minimal number of times to match.
    max - the maximal number of times to match.
    
    Returns:
    the new Pattern object.
  - not
```
public final Pattern not()
```
    If this pattern matches, return mismatch. return match length 0 otherwise.
    
    Returns:
    the new Pattern object.
  - peek
```
public final Pattern peek()
```
    Matches with match length 0 if this Pattern object matches. Mismatch otherwise.
    
    Returns:
    the new Pattern object.
  - ifelse
```
public final Pattern ifelse(Pattern yes,
             Pattern no)
```
    If this pattern matches, match the remaining input against Pattern object yes. Otherwise, match the input against Pattern object no.
    
    Parameters:
    yes - the true Pattern.
    no - the false Pattern.
    
    Returns:
    the new Pattern object.
  - repeat
```
public final Pattern repeat(int n)
```
    Matches the input against this pattern for n times.
    
    Parameters:
    n - the number of times to match.
    
    Returns:
    the new Pattern object.

Class Pattern

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MISMATCH

Constructor Detail

Pattern

Method Detail

match

seq

optional

many

many

many1

some

some

not

peek

ifelse

repeat