openlist.reader
Class SExpressionReader

java.lang.Object
  java.io.StreamTokenizer
      openlist.reader.SExpressionReader

public class SExpressionReader
extends java.io.StreamTokenizer

SExpressionReader provides a reader for OpenLists and atoms. In addition to tokenizing for atoms of specific types: Doubles, Longs, and Strings (which are interned as Symbols), an entire OpenList can be read by a single method call, assuming the input is in the form of an S expression. In an S expression, the elements of a OpenLists are shown in parentheses with a space between each element. (The elements can themselves be S expressions representing OpenLists.)

Field Summary

private int	buff
private static char	FORM_FEED
private static char	LEFT_PAREN
private long	lval
private static char	NEWLINE
private static char	RETURN
private static char	RIGHT_PAREN
private static char	SPACE
private static char	TAB
private static int	TT_LONG
private boolean	valid

Fields inherited from class java.io.StreamTokenizer

nval, sval, TT_EOF, TT_EOL, TT_NUMBER, TT_WORD, ttype

Constructor Summary

SExpressionReader(java.io.InputStream I)
Construct an SExpressionReader from an InputStream

SExpressionReader(java.io.Reader R)
Construct an SExpressionReader from a Reader.

Method Summary

void	exceptionHandler(java.lang.Exception e) exceptionHandler can be over-ridden to handle IO exceptions
private void	get() Get the next token from the input.
(package private) OpenList<java.lang.Object>	getRestSexp() Get the rest of a started S expression from input stream.
private void	getSkippingWhiteSpace() Skip any whitespace, then get the next token from the input.
private boolean	isWhiteSpace(int c) Determine whether a character is white space
java.lang.Object	nextSexp() Get next S expression from input stream.
int	nextToken() Get token and return TT_LONG, TT_NUMBER, TT_WORD, or TT_EOF
private void	putBack(int c) Put a character back into the input.

Methods inherited from class java.io.StreamTokenizer

commentChar, eolIsSignificant, lineno, lowerCaseMode, ordinaryChar, ordinaryChars, parseNumbers, pushBack, quoteChar, resetSyntax, slashSlashComments, slashStarComments, toString, whitespaceChars, wordChars

Methods inherited from class java.lang.Object

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

Field Detail

TT_LONG

private static final int TT_LONG

See Also:

Constant Field Values

lval

private long lval

buff

private int buff

valid

private boolean valid

LEFT_PAREN

private static final char LEFT_PAREN

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Constant Field Values

RIGHT_PAREN

private static final char RIGHT_PAREN

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Constant Field Values

SPACE

private static final char SPACE

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Constant Field Values

TAB

private static final char TAB

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Constant Field Values

NEWLINE

private static final char NEWLINE

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Constant Field Values

RETURN

private static final char RETURN

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Constant Field Values

FORM_FEED

private static final char FORM_FEED

See Also:

Constant Field Values

Constructor Detail

SExpressionReader

public SExpressionReader(java.io.InputStream I)

Construct an SExpressionReader from an InputStream

SExpressionReader

public SExpressionReader(java.io.Reader R)

Construct an SExpressionReader from a Reader.

Method Detail

exceptionHandler

public void exceptionHandler(java.lang.Exception e)

exceptionHandler can be over-ridden to handle IO exceptions

isWhiteSpace

private boolean isWhiteSpace(int c)

Determine whether a character is white space

get

private void get()

Get the next token from the input. This is a hand-implemented get/putBack system, since the one in StreamOpenListReader didn't work well at one time.

getSkippingWhiteSpace

private void getSkippingWhiteSpace()

Skip any whitespace, then get the next token from the input.

putBack

private void putBack(int c)

Put a character back into the input.

Parameters:

c - the character to be put back

nextToken

public int nextToken()

Get token and return TT_LONG, TT_NUMBER, TT_WORD, or TT_EOF

Overrides:

nextToken in class java.io.StreamTokenizer

nextSexp

public java.lang.Object nextSexp()

Get next S expression from input stream. Returns an object of class EndOfFile on end-of-file.

getRestSexp

OpenList<java.lang.Object> getRestSexp()

Get the rest of a started S expression from input stream. Returns the empty list on end-of-file.