com.coasttocoastresearch.apg
Class Parser.UdtCallback

java.lang.Object
  com.coasttocoastresearch.apg.Parser.UdtCallback

Direct Known Subclasses:

UdtLib.Alphanum, UdtLib.Any, UdtLib.CComment, UdtLib.Comment, UdtLib.DecNum, UdtLib.HexNum, UdtLib.LineEnd, UdtLib.QuotedString, UdtLib.WhiteSpace

Enclosing class:

Parser

public abstract static class Parser.UdtCallback
extends java.lang.Object

Base class for all User-Defined Terminals (UDTs).

Field Summary

Parser.CallbackData

callbackData Parser-provisioned data available to all UDT callback functions

Constructor Summary

Parser.UdtCallback(Parser parser)
Base class constructor for the UDT callback functions.

Method Summary

abstract int

callback(int offset) The UDT function.

Methods inherited from class java.lang.Object

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

Field Detail

callbackData

public final Parser.CallbackData callbackData

Parser-provisioned data available to all UDT callback functions

Constructor Detail

Parser.UdtCallback

public Parser.UdtCallback(Parser parser)

Base class constructor for the UDT callback functions.

Parameters:

parser - the instance of the Parser to attach this callback function to.

Method Detail

callback

public abstract int callback(int offset)
                      throws java.lang.Exception

The UDT function.

Parameters:

offset - offset into the input string to the first character of the parsed phrase.

Returns:

the matched phrase length, L, or -1 if no phrase was matched. The phrase length must be in the range 0 <= L <=(n-1), where n is the remaining number of characters in the input string.

Throws:

java.lang.Exception - thrown if the callback function returns an illegal value. An illegal value would be a phrase length L >= n, or Illegal values are phrase lengths longer than the length of the remaining input string or a zero (empty) length by a UDT designated as non-empty. (UDTs having names beginning with "u_" are designated as non-empty. UDTs having names beginning with "e_" are designated as empty.)