ec.util

Class Lexer

java.lang.Object

ec.util.Lexer

public class Lexer
extends Object

A simple line-by-line String tokenizer. You provide Lexer with a String or other CharSequence as input, plus an array of regular expressions. Each time you call nextToken(...), the Lexer matches the next token against the regular expressions and returns it. The regular expressions are checked in order, and the first one that matches is the winner.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FAILURE An index which indicates that no further tokens were found.
(package private) CharSequence	input
(package private) Matcher[]	matchers
(package private) int	matchingIndex
(package private) int	position
(package private) String[]	regexps

Constructor Summary

Constructors

Constructor and Description
Lexer(CharSequence input, String[] regexps) Builds a Lexer for the given input with the provided regular expressions.

Method Summary

Modifier and Type	Method and Description
int	getMatchingIndex() Returns the index of the regular expression which matched the most recent token.
int	getMatchingPosition() Returns the position in the String just beyond the most recent token.
String	getMatchingRule() Returns the regular expression which matched the most recent token.
String	nextToken() Returns the next token as a string.
String	nextToken(boolean trim) Returns the next token as a string.

Methods inherited from class java.lang.Object

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

Field Detail

FAILURE

public static final int FAILURE

An index which indicates that no further tokens were found. This could be due to the end of the string or due to a bad string. You'll need to check the index to determine for sure.

See Also:

Constant Field Values

input

CharSequence input

position

int position

matchers

Matcher[] matchers

regexps

String[] regexps

matchingIndex

int matchingIndex

Constructor Detail

Lexer

public Lexer(CharSequence input,
             String[] regexps)

Builds a Lexer for the given input with the provided regular expressions. The regular expressions will be checked in order against the input, and the first one which matches will be assumed to be the token.

Method Detail

nextToken

public String nextToken(boolean trim)

Returns the next token as a string. If *trim* is true, then the string is first trimmed of whitespace.

nextToken

public String nextToken()

Returns the next token as a string. The string is first trimmed of whitespace.

getMatchingIndex

public int getMatchingIndex()

Returns the index of the regular expression which matched the most recent token.

getMatchingRule

public String getMatchingRule()

Returns the regular expression which matched the most recent token.

getMatchingPosition

public int getMatchingPosition()

Returns the position in the String just beyond the most recent token.