wizx.lang
Class ExpressionTokenizer

java.lang.Object
  wizx.lang.ExpressionTokenizer

public class ExpressionTokenizer

extends java.lang.Object

Tokenizes expression text. Each call to nextToken returns one of the following:

• a number literal - an openning # and any text up to and including a matching #
• a boolean literal - an openning * and any text up to and including a matching *
• a string literal - an openning " and any text up to and including a matching "
• a name token - a string of consecutive letters, numbers underscores and dashes
• a list construction delimiter - '{' or '}'
• a record construction delimiter - '[' or ']'
• a grouping delimiter - '(' or ')'
• a record deconstruction delimiter - .
• a pair construction delimiter - ,

Constructor Summary

ExpressionTokenizer(java.lang.String s)

Method Summary

void	fail(java.lang.String message)
boolean	hasMoreTokens()
boolean	isNameChar(char c)
java.lang.String	nextToken() Returns the next token or null.
char	peek()

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionTokenizer

public ExpressionTokenizer(java.lang.String s)

Parameters:

s - the string to parse.

Throws:

java.lang.NullPointerException - if s is null.

Method Detail

hasMoreTokens

public boolean hasMoreTokens()

peek

public char peek()

nextToken

public java.lang.String nextToken()
                           throws java.text.ParseException

Returns the next token or null.

Throws:

java.text.ParseException - if an illegal token is encountered.

isNameChar

public boolean isNameChar(char c)

fail

public void fail(java.lang.String message)
          throws java.text.ParseException

Throws:

java.text.ParseException