au.com.zip.cs
Class IO

java.lang.Object
  au.com.zip.cs.IO

public final class IO
extends Object

Assorted I/O convenience routines.

Author:

Cameron Simpson <cs@zip.com.au> 2mar2002

Constructor Summary

IO()

Method Summary

static String	getContLine(LineStackReader r) Read a line and all subsequent lines commencing with a space or tab.
static String	getSloshLine(BufferedReader r) Read a slosh ('\\') extended line from a BufferedReader, discarding the sloshes.
static String	getSloshLine(BufferedReader r, boolean keepSlosh) Read a slosh ('\\') extended line from a BufferedReader, optionally discarding the sloshes.
static int	probe(PushbackReader r) Return the next characters which would come from a PushbackReader, which may be EOF.
static StringBuffer	readAll(Reader r) Read all the remaining characters from a Reader and return them in a single StringBuffer.
static char	readChar(Reader r) Just like Reader.read() except that EOF is an exception and so we can return a char.
static int	readHex1(Reader r) Read a single hexadecimal numeral from a Reader and return its hex value.
static int	readHex2(Reader r) Read two hexadecimal numerals from a Reader and return their value.
static int	readHex4(Reader r) Read four hexadecimal numerals from a Reader and return their value.
static StringBuffer	readTo(PushbackReader r, String delims) Read characters from a PushbackReader until one of the delimiters listed in the String delims is reached.
static StringBuffer	readTo(PushbackReader r, String delims, StringBuffer b) Read characters from a PushbackReader until one of the delimiters listed in the String delims is reached, appending to the supplied StringBuffer.
static StringBuffer	readWord(PushbackReader r) Read an identifier from a PushbackReader.
static void	skipWhite(PushbackReader r) Skip past any whitespace characters at the start of a PushbackReader.
static void	unreadChar(PushbackReader r, char ch) Just like PushbackReader.unread(int) except that it only takes chars.

Methods inherited from class java.lang.Object

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

Constructor Detail

IO

public IO()

Method Detail

readChar

public static final char readChar(Reader r)
                           throws IOException

Just like Reader.read() except that EOF is an exception and so we can return a char.

Parameters:

r - the Reader from which to read

Throws:

IOException

unreadChar

public static final void unreadChar(PushbackReader r,
                                    char ch)
                             throws IOException

Just like PushbackReader.unread(int) except that it only takes chars. It seems that unread(int), which takes an int, transmutes EOF (-1) into 65535, and so although it permits pushing back EOF, this breaks the stream.

Parameters:

r - the Reader from which to read

ch - the char to push back

Throws:

IOException

probe

public static final int probe(PushbackReader r)
                       throws IOException

Return the next characters which would come from a PushbackReader, which may be EOF.

Parameters:

r - the PushbackReader

Returns:

the next character

Throws:

IOException

readTo

public static final StringBuffer readTo(PushbackReader r,
                                        String delims)
                                 throws IOException

Read characters from a PushbackReader until one of the delimiters listed in the String delims is reached. The delimiter is left on the Reader.

Parameters:

r - a PushbackReader from which to read

delims - a list of stop characters

Returns:

a StringBuffer containing the characters read

Throws:

IOException

readTo

public static final StringBuffer readTo(PushbackReader r,
                                        String delims,
                                        StringBuffer b)
                                 throws IOException

Read characters from a PushbackReader until one of the delimiters listed in the String delims is reached, appending to the supplied StringBuffer. A new StringBuffer is allocated if the supplied one is null. The delimiter is left on the Reader.

Parameters:

r - a PushbackReader from which to read

delims - a list of stop characters

b - the StringBuffer

Returns:

the StringBuffer containing the characters read

Throws:

IOException

readWord

public static final StringBuffer readWord(PushbackReader r)
                                   throws IOException

Read an identifier from a PushbackReader.

Parameters:

r - the stream from which to read

Returns:

a StringBuffer holding the word, if any

Throws:

IOException

readHex1

public static final int readHex1(Reader r)
                          throws IOException,
                                 ParseException

Read a single hexadecimal numeral from a Reader and return its hex value.

Parameters:

r - the stream from which to read

Returns:

the value of the numeral

Throws:

ParseException - thrown when a hexadecimal numeral was found

IOException

readHex2

public static final int readHex2(Reader r)
                          throws IOException,
                                 ParseException

Read two hexadecimal numerals from a Reader and return their value.

Parameters:

r - the stream from which to read

Returns:

the value of the numerals

Throws:

ParseException - thrown when less than two hexadecimal numerals were found

IOException

readHex4

public static final int readHex4(Reader r)
                          throws IOException,
                                 ParseException

Read four hexadecimal numerals from a Reader and return their value.

Parameters:

r - the stream from which to read

Returns:

the value of the numerals

Throws:

ParseException - thrown when less than four hexadecimal numerals were found

IOException

skipWhite

public static void skipWhite(PushbackReader r)
                      throws IOException

Skip past any whitespace characters at the start of a PushbackReader.

Parameters:

r - the stream from which to read

Throws:

IOException

getSloshLine

public static String getSloshLine(BufferedReader r)
                           throws IOException

Read a slosh ('\\') extended line from a BufferedReader, discarding the sloshes.

Parameters:

r - the stream from which to read

Returns:

the multiline, or null at EOF

Throws:

IOException

getSloshLine

public static String getSloshLine(BufferedReader r,
                                  boolean keepSlosh)
                           throws IOException

Read a slosh ('\\') extended line from a BufferedReader, optionally discarding the sloshes. The trailing newline of the last (unsloshed) line collected is discarded.

Parameters:

r - the stream from which to read

keepSlosh - whether to keep the sloshes

Returns:

the multiline, or null at EOF

Throws:

IOException

getContLine

public static String getContLine(LineStackReader r)
                          throws IOException

Read a line and all subsequent lines commencing with a space or tab.

Parameters:

r - the LineStackReader from which to read lines

Throws:

IOException

readAll

public static StringBuffer readAll(Reader r)
                            throws IOException

Read all the remaining characters from a Reader and return them in a single StringBuffer.

Parameters:

r - the stream from which to read

Returns:

a StringBuffer holding the data

Throws:

IOException