edu.rice.cs.util
Class BalancingStreamTokenizer

java.lang.Object
  edu.rice.cs.util.BalancingStreamTokenizer

public class BalancingStreamTokenizer
extends Object

A tokenizer that splits a stream into string tokens while balancing quoting characters.

Version:

$Id$

Author:

Mathias Ricken

Nested Class Summary

static class	BalancingStreamTokenizer.KeywordStartsWithQuoteException Keyword starts with quote exception.
static class	BalancingStreamTokenizer.KeywordStartsWithWhitespaceException Keyword starts with whitespace exception.
static class	BalancingStreamTokenizer.QuoteStartsWithWhitespaceException Quote starts with whitespace exception.
static class	BalancingStreamTokenizer.SetupException Setup exception.
static class	BalancingStreamTokenizer.StartsWithWhitespaceException Quote or keyword starts with whitespace exception.
static class	BalancingStreamTokenizer.State State of the tokenizer.
static class	BalancingStreamTokenizer.Token Kind of tokens to be returned.

Field Summary

protected Character	_escape Escape character, if available.
protected boolean	_isEscape The current character is the escape character.
Stack<Integer>	_pushed Stack of characters having been pushed back.
protected Reader	_reader Input Reader.
protected BalancingStreamTokenizer.State	_state Current state of the tokenizer.
protected Stack<BalancingStreamTokenizer.State>	_stateStack Stack of previous states.
BalancingStreamTokenizer.Token	_token
protected boolean	_wasEscape The previous character was the escape character.

Constructor Summary

BalancingStreamTokenizer(Reader r)
Create a new balancing stream tokenizer.

BalancingStreamTokenizer(Reader r, Character escape)
Create a new balancing stream tokenizer.

Method Summary

void	addKeyword(String kw) Specify a new keyword.
void	addQuotes(String begin, String end) Specify a pair of quotes.
void	defaultThreeQuoteCurlySetup() Setup a tokenizer that recognizes ", ' and ` quotes and { } braces.
void	defaultThreeQuoteDollarCurlySetup() Setup a tokenizer that recognizes ", ' and ` quotes and ${ } braces.
void	defaultThreeQuoteSetup() Setup a tokenizer that recognizes ", ' and ` quotes.
void	defaultTwoQuoteCurlySetup() Setup a tokenizer that recognizes " and ' quotes and { } braces.
void	defaultTwoQuoteSetup() Setup a tokenizer that recognizes " and ' quotes.
void	defaultWhitespaceSetup() Setup a tokenizer with just whitespace.
protected String	escape(String s)
protected String	findMatch(int c, TreeSet<String> choices, Lambda<String,String> notFoundLambda)
String	getNextToken() Return the next token, or null if the end of the stream has been reached.
BalancingStreamTokenizer.State	getState() Return a copy of the current state of the tokenizer.
protected int	nextToken() Return the next token from the reader, or from the stack if it isn't empty.
protected void	popState() Pops the top of the state stack and makes it the current state.
static TreeSet<String>	prefixSet(Set<String> set, String prefix) Return the subset of the set whose entries begin with the prefix.
protected void	pushState() Push the current state onto the stack.
protected void	pushToken(int token) Push a token back onto the stack.
void	setState(BalancingStreamTokenizer.State state) Set the stream tokenizer the the state specified.
BalancingStreamTokenizer.Token	token() Returns the type of the current token.
protected String	unescape(String s)
void	whitespace(int... c) Specify one or more characters as whitespace.
void	whitespaceRange(int lo, int hi) Specify a range characters as whitespace.
void	wordChars(int... c) Specify one or more characters as word characters.
void	wordRange(int lo, int hi) Specify a range characters as word characters.

Methods inherited from class java.lang.Object

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

Field Detail

_reader

protected Reader _reader

Input Reader.

_pushed

public Stack<Integer> _pushed

Stack of characters having been pushed back.

_state

protected BalancingStreamTokenizer.State _state

Current state of the tokenizer.

_stateStack

protected Stack<BalancingStreamTokenizer.State> _stateStack

Stack of previous states.

_escape

protected Character _escape

Escape character, if available. If this character is placed in front of any quote or keyword, the quote or keyword is treated as normal text. To get this character to exist alone, it has to be doubled up. If this escape character appears alone where it does not precede another escape character, whitespace, a quote or keyword, it is dropped. The escape character CANNOT be declared whitespace. The escape character CAN be part of a quote or keyword, but it has to be doubled up in the string, and when the quotes or keywords are added, the escape character is automatically doubled up if present. If set to null, no escaping is possible.

_wasEscape

protected boolean _wasEscape

The previous character was the escape character.

_isEscape

protected boolean _isEscape

The current character is the escape character.

_token

public volatile BalancingStreamTokenizer.Token _token

Constructor Detail

BalancingStreamTokenizer

public BalancingStreamTokenizer(Reader r)

Create a new balancing stream tokenizer.

Parameters:

r - reader to tokenize

BalancingStreamTokenizer

public BalancingStreamTokenizer(Reader r,
                                Character escape)

Create a new balancing stream tokenizer.

Parameters:

r - reader to tokenize

escape - escape character or null

Method Detail

defaultWhitespaceSetup

public void defaultWhitespaceSetup()

Setup a tokenizer with just whitespace.

defaultTwoQuoteSetup

public void defaultTwoQuoteSetup()

Setup a tokenizer that recognizes " and ' quotes.

defaultThreeQuoteSetup

public void defaultThreeQuoteSetup()

Setup a tokenizer that recognizes ", ' and ` quotes.

defaultTwoQuoteCurlySetup

public void defaultTwoQuoteCurlySetup()

Setup a tokenizer that recognizes " and ' quotes and { } braces.

defaultThreeQuoteCurlySetup

public void defaultThreeQuoteCurlySetup()

Setup a tokenizer that recognizes ", ' and ` quotes and { } braces.

defaultThreeQuoteDollarCurlySetup

public void defaultThreeQuoteDollarCurlySetup()

Setup a tokenizer that recognizes ", ' and ` quotes and ${ } braces.

nextToken

protected int nextToken()
                 throws IOException

Return the next token from the reader, or from the stack if it isn't empty.

Returns:

next token or -1 when end of stream

Throws:

IOException

pushToken

protected void pushToken(int token)

Push a token back onto the stack.

Parameters:

token - token to push back

getState

public BalancingStreamTokenizer.State getState()

Return a copy of the current state of the tokenizer.

Returns:

copy of the state

setState

public void setState(BalancingStreamTokenizer.State state)

Set the stream tokenizer the the state specified.

Parameters:

state - state

pushState

protected void pushState()

Push the current state onto the stack.

popState

protected void popState()

Pops the top of the state stack and makes it the current state.

token

public BalancingStreamTokenizer.Token token()

Returns the type of the current token.

wordRange

public void wordRange(int lo,
                      int hi)

Specify a range characters as word characters.

Parameters:

lo - the character beginning the word character range, inclusive

hi - the character ending the word character range, inclusive

wordChars

public void wordChars(int... c)

Specify one or more characters as word characters.

Parameters:

c - the character(s)

whitespaceRange

public void whitespaceRange(int lo,
                            int hi)

Specify a range characters as whitespace.

Parameters:

lo - the character beginning the whitespace range, inclusive

hi - the character ending the whitespace range, inclusive

whitespace

public void whitespace(int... c)

Specify one or more characters as whitespace.

Parameters:

c - the character(s)

addQuotes

public void addQuotes(String begin,
                      String end)

Specify a pair of quotes.

Parameters:

begin - the beginning quotation mark

end - the ending quotation mark

addKeyword

public void addKeyword(String kw)

Specify a new keyword.

Parameters:

kw - the new keyword

getNextToken

public String getNextToken()
                    throws IOException

Return the next token, or null if the end of the stream has been reached.

Returns:

next token, or null if end of stream has been reached.

Throws:

IOException

prefixSet

public static TreeSet<String> prefixSet(Set<String> set,
                                        String prefix)

Return the subset of the set whose entries begin with the prefix.

Parameters:

set - parent set

prefix - prefix string

Returns:

subset of only those entries that begin with the prefix

findMatch

protected String findMatch(int c,
                           TreeSet<String> choices,
                           Lambda<String,String> notFoundLambda)
                    throws IOException

Throws:

IOException

escape

protected String escape(String s)

unescape

protected String unescape(String s)