monq.jfa.ctx

Class Context

java.lang.Object

monq.jfa.AbstractFaAction

monq.jfa.ctx.Context

All Implemented Interfaces:

java.io.Serializable, FaAction

public class Context
extends AbstractFaAction

manages a context when running a DfaRun. A context is the stretch of text between and including the matches of a pair of regular expressions. To add the two regular expressions to an Nfa and associate them with a Context object, use a ContextManager.

The Context object allows for a client action to be run just before the context is entered and immediatly after the context ends. Their default derives from the defaults set up in the ContextManager. They can be changed with setStartAction() and setEndAction(). Normally they are used to handle the text matching the regular expressions defining the context.

The client actions may push/pop elements on/from the List provided via the ContextStackProvider that must be available in DfaRun.clientData field. Of course the number of elements pushed and popped must match.

To define how the DfaRun should handle unmatched text within the context, call setFMB().

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
java.lang.String	getName() returns the name of this Context.
void	invoke(java.lang.StringBuilder yytext, int start, DfaRun r) is called by methods of DfaRun in case of a match.
Context	setEndAction(FaAction a) specifies the action which takes care of the text marking the end of the context.
Context	setFMB(DfaRun.FailedMatchBehaviour fmb) specifies how the DfaRun should handle non-matching text within the context.
Context	setName(java.lang.String s) sets the name of this object, which is currently only used to have toString() return something useful.
Context	setPopPriority(int p) this method is not implemented and will always throw an exception.
Context	setStartAction(FaAction a) specifies the action which shall take care of the text marking the start of the context.
java.lang.String	toString()

Methods inherited from class monq.jfa.AbstractFaAction

mergeWith, setPriority

Methods inherited from class java.lang.Object

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

Method Detail

setName

public Context setName(java.lang.String s)

sets the name of this object, which is currently only used to have toString() return something useful.

getName

public java.lang.String getName()

returns the name of this Context. If the name was never set, this is null.

Returns:

the name which was set with setName(java.lang.String).

setStartAction

public Context setStartAction(FaAction a)

specifies the action which shall take care of the text marking the start of the context. The default for this action is set up with ContextManager.setDefaultStartAction().

setEndAction

public Context setEndAction(FaAction a)

specifies the action which takes care of the text marking the end of the context. The default for this action is set up with ContextManager.setDefaultEndAction().

setFMB

public Context setFMB(DfaRun.FailedMatchBehaviour fmb)

specifies how the DfaRun should handle non-matching text within the context.

setPopPriority

public Context setPopPriority(int p)

this method is not implemented and will always throw an exception. It is only kept as a refence for the rare cases when someone thinks it is necessary to set the priority of the context pop action. This, however, can only be necessary if there is a conflict between matches within the context and the match terminating the context. While this is probably wrong anyway, it is still possible to give the action handling the in-context match a priority different from zero to make it different from the priority of the pop action.

Throws:

java.lang.UnsupportedOperationException - whenever called.

invoke

public void invoke(java.lang.StringBuilder yytext,
                   int start,
                   DfaRun r)
            throws CallbackException

Description copied from interface: FaAction

is called by methods of DfaRun in case of a match. Parameter yytext contains the matching text from position start onwards. The callback may change the whole of yytext, but the under most circumstances, only the matching text should be changed. Parameter runner is the DfaRun object which called this function. Of interest are its fields DfaRun.clientData and DfaRun.collect.

Throws:

CallbackException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object