gshute.ioutil
Class LineScanner

java.lang.Object
  |
  +--gshute.ioutil.LineScanner

public class LineScanner

extends java.lang.Object

An object of class LineScanner scans text, breaking it up into tokens.

Field Summary

protected int	currentPosition currentPosition is the beginning position in text of currentToken.
protected java.lang.StringBuffer	currentToken currentToken is a StringBuffer containing the current token of this LineScanner.
protected int	currentTokenEnd currentTokenEnd the end position in text of currentToken.
protected int	currentType currentType is the type of currentToken.
static int	ECHO
protected int	echoPolicy echoPolicy determines if this LineScanner echoes lines before printing errors.
protected java.util.Vector	errors errors is a Vector of errors that have been recorded in this LineScanner.
static int	NO_ECHO
protected static int	t_end
protected static int	t_escape_error
protected static int	t_float
protected static int	t_int
protected static int	t_string
protected static int	t_unmatched These are the token type constants.
protected java.lang.String	text text is the text that this LineScanner is reading.
protected int	textLength textLength is the length of text.

Constructor Summary

LineScanner(java.lang.String str, int echoPol)
new LineScanner(str, echoPol) returns a new LineScanner for scanning str.

LineScanner(java.lang.String str, int echoPol, int skip)
new LineScanner(str, echoPol, skip) returns a new LineScanner for scanning str.

Method Summary

void	addError(java.lang.String msg) ls.addError(msg) adds msg to the error list for ls.
void	advance() ls.advance() advances the current position in ls.
boolean	atChar() ls.atChar() returns true if the token at the current position of ls is a character.
boolean	atEnd() ls.atEnd() returns true if the current position of ls is at the end of the line.
boolean	atFloat() ls.atFloat() returns true if the token at the current position of ls is a float.
boolean	atInt() ls.atInt() returns true if the token at the current position of ls is an int.
boolean	atString() ls.atString() returns true if the token at the current position of ls is a string.
protected void	classifyToken() ls.classifyToken() sets currentType to the type of the current token of ls.
protected void	copyToken() copyToken() copies the current token of this LineScanner into currentToken and sets currentTokenEnd to the position just beyond the end of the current token string.
char	currentChar() ls.currentChar() returns the string value of the current token of ls.
float	currentFloat() ls.currentFloat() returns the float value of the current token of ls.
int	currentInt() ls.currentInt() returns the int value of the current token of ls.
java.lang.String	currentString() ls.currentString() returns the string value of the current token of ls.
int	errorCount() ls.errorCount() returns the number of error messages in ls.
int	getEchoPolicy() ls.getEchoPolicy(echoPol) returns the echo policy of ls.
java.lang.String	getText() ls.getText(echoPol) returns the text of ls.
protected int	getToMatch(int pos) getToMatch(pos) returns the position in text of the character just beyond the first unescaped match for the character at pos.
void	printAllErrors() ls.printAllErrors() prints all of the error messages in ls to System.out.
protected void	printError(int i) ls.printError(i) prints the i-th error message in ls to stdout.
void	printFirstError() ls.printFirstError() prints the first error message in ls to System.out, if there is one.
char	readChar() ls.readChar() returns the character value of the current token of ls, then advances the current position.
void	readEnd() ls.readEnd() records an error message in ls if the current position of ls is not at the end of the line.
float	readFloat() ls.readFloat() returns the float value of the current token of ls, then advances the current position.
int	readInt() ls.readInt() returns the int value of the current token of ls, then advances the current position.
java.lang.String	readString() ls.readString() returns the string value of the current token of ls, then advances the current position.
void	removeLastError() ls.removeLastError() removes the last error message from ls.
void	setEchoPolicy(int echoPol) ls.setEchoPolicy(echoPol) changes the echo policy of ls to echoPol.
void	setText(java.lang.String str) ls.setText(str) resets ls in preparation for scanning str.
void	setText(java.lang.String str, int skip) ls.setText(str, skip) resets ls in preparation for scanning str.
protected int	translateEscapeCharacter(int pos) translateEscapeCharacter(pos) appends the translation for the escape sequence at pos to currentToken and returns the position just beyond the escape sequence.

Methods inherited from class java.lang.Object

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

Field Detail

NO_ECHO

public static final int NO_ECHO

ECHO

public static final int ECHO

text

protected java.lang.String text

text is the text that this LineScanner is reading.

textLength

protected int textLength

textLength is the length of text.

currentToken

protected java.lang.StringBuffer currentToken

currentToken is a StringBuffer containing the current token of this LineScanner.

currentType

protected int currentType

currentType is the type of currentToken.

currentPosition

protected int currentPosition

currentPosition is the beginning position in text of currentToken.

currentTokenEnd

protected int currentTokenEnd

currentTokenEnd the end position in text of currentToken.

echoPolicy

protected int echoPolicy

echoPolicy determines if this LineScanner echoes lines before printing errors.

errors

protected java.util.Vector errors

errors is a Vector of errors that have been recorded in this LineScanner.

t_unmatched

protected static final int t_unmatched

These are the token type constants.

t_escape_error

protected static final int t_escape_error

t_string

protected static final int t_string

t_float

protected static final int t_float

t_int

protected static final int t_int

t_end

protected static final int t_end

Constructor Detail

LineScanner

public LineScanner(java.lang.String str,
                   int echoPol,
                   int skip)

new LineScanner(str, echoPol, skip) returns a new LineScanner for scanning str. The new LineScanner uses echoPol to determine echo policy for error messages. This parameter should have one of the values LineScanner.ECHO or LineScanner.NO_ECHO. The parameter skip specifies the number of characters to skip in str before scanning.

LineScanner

public LineScanner(java.lang.String str,
                   int echoPol)

new LineScanner(str, echoPol) returns a new LineScanner for scanning str. The new LineScanner uses echoPol to determine echo policy for error messages. This parameter should have one of the values LineScanner.ECHO or LineScanner.NO_ECHO.

Method Detail

setText

public void setText(java.lang.String str,
                    int skip)

ls.setText(str, skip) resets ls in preparation for scanning str. The echo policy of ls is not changed. The parameter skip specifies the number of characters to skip in str befor scanning.

setText

public void setText(java.lang.String str)

ls.setText(str) resets ls in preparation for scanning str. The echo policy of ls is not changed.

setEchoPolicy

public void setEchoPolicy(int echoPol)

ls.setEchoPolicy(echoPol) changes the echo policy of ls to echoPol. This parameter should have one of the values LineScanner.ECHO or LineScanner.NO_ECHO.

getText

public java.lang.String getText()

ls.getText(echoPol) returns the text of ls.

getEchoPolicy

public int getEchoPolicy()

ls.getEchoPolicy(echoPol) returns the echo policy of ls.

readString

public java.lang.String readString()

ls.readString() returns the string value of the current token of ls, then advances the current position. If an error occurs, a message is recorded in ls. Error messages: Unterminated quote. String expected.

readChar

public char readChar()

ls.readChar() returns the character value of the current token of ls, then advances the current position. If an error occurs, a message is recorded in ls. Error messages: Unterminated quote. Character expected.

readFloat

public float readFloat()

ls.readFloat() returns the float value of the current token of ls, then advances the current position. If an error occurs, a message is recorded in ls. Error messages: Real number expected.

readInt

public int readInt()

ls.readInt() returns the int value of the current token of ls, then advances the current position. If an error occurs, a message is recorded in ls. Error messages: Integer expected.

readEnd

public void readEnd()

ls.readEnd() records an error message in ls if the current position of ls is not at the end of the line. Error messages: No more arguments expected.

atString

public boolean atString()

ls.atString() returns true if the token at the current position of ls is a string.

atChar

public boolean atChar()

ls.atChar() returns true if the token at the current position of ls is a character.

atFloat

public boolean atFloat()

ls.atFloat() returns true if the token at the current position of ls is a float.

atInt

public boolean atInt()

ls.atInt() returns true if the token at the current position of ls is an int.

atEnd

public boolean atEnd()

ls.atEnd() returns true if the current position of ls is at the end of the line.

currentString

public java.lang.String currentString()

ls.currentString() returns the string value of the current token of ls. If an error occurs, a message is recorded in ls. Preconditions: ls.atString() is true.

currentChar

public char currentChar()

ls.currentChar() returns the string value of the current token of ls. If an error occurs, a message is recorded in ls. Preconditions: ls.atChar() is true.

currentFloat

public float currentFloat()

ls.currentFloat() returns the float value of the current token of ls. If an error occurs, a message is recorded in ls. Preconditions: ls.atFloat() is true.

currentInt

public int currentInt()

ls.currentInt() returns the int value of the current token of ls. If an error occurs, a message is recorded in ls. Preconditions: ls.atInt() is true.

advance

public void advance()

ls.advance() advances the current position in ls. Preconditions: ls.atEnd() is false.

errorCount

public int errorCount()

ls.errorCount() returns the number of error messages in ls.

addError

public void addError(java.lang.String msg)

ls.addError(msg) adds msg to the error list for ls. The position for this error is the current position of ls.

removeLastError

public void removeLastError()

ls.removeLastError() removes the last error message from ls. Preconditions: ls.errorCount() > 0.

printFirstError

public void printFirstError()

ls.printFirstError() prints the first error message in ls to System.out, if there is one.

printAllErrors

public void printAllErrors()

ls.printAllErrors() prints all of the error messages in ls to System.out.

copyToken

protected void copyToken()

copyToken() copies the current token of this LineScanner into currentToken and sets currentTokenEnd to the position just beyond the end of the current token string.

getToMatch

protected int getToMatch(int pos)

getToMatch(pos) returns the position in text of the character just beyond the first unescaped match for the character at pos.

translateEscapeCharacter

protected int translateEscapeCharacter(int pos)

translateEscapeCharacter(pos) appends the translation for the escape sequence at pos to currentToken and returns the position just beyond the escape sequence.

classifyToken

protected void classifyToken()

ls.classifyToken() sets currentType to the type of the current token of ls.

printError

protected void printError(int i)

ls.printError(i) prints the i-th error message in ls to stdout.