monq.jfa.ctx

Class ContextManager

java.lang.Object

monq.jfa.ctx.ContextManager

public class ContextManager
extends java.lang.Object

populates a Nfa with regex/action pairs which keep track of nested matching contexts. Objects of this class are expected to be used as follows:

1. Create the object with a client Nfa to populate.
2. Configure some defaults, if necessary, with the setDefault... methods.
3. Add contexts to the Nfa with any of the add...() methods.
4. Add more regex/action pairs directly to the Nfa, typically with calls like

    .or("regex", new IfContext().ifthen(ctx, action))

   where ctx is a context returned by a one of the add...() methods.

Note that changing the defaults on this object will have effect only for subsequent add...() calls.

Field Summary

Fields

Modifier and Type	Field and Description
static Context	anyContext

Constructor Summary

Constructors

Constructor and Description
ContextManager(Nfa nfa) creates an object to populate the given Nfa with regex/action pairs for context matching.

Method Summary

Modifier and Type	Method and Description
Context	add(Context parent, java.lang.String reIn, java.lang.String reOut) adds a new context to the client Nfa.
Context	add(java.lang.String reIn, java.lang.String reOut) calls add(Context,String,String) such that the context is entered in any parent context.
Context	addXml() calls add(Context,String,String) such that reIn and reOut match the start and end of any XML element.
Context	addXml(Context parent, java.lang.String tagname) calls add(parent,reIn,reOut) such that reIn and reOut match the start and end of the XML element with the given tagname.
Context[]	addXml(Context parent, java.lang.String[] tagnames) creates a nested hierarchy of contexts defined by the XML tagnames given.
Context	addXml(java.lang.String tagname) calls add(Context,String,String) such that reIn and reOut match the start and end of the XML element with the given tagname.
static java.lang.Object	createStackProvider() is a convenience method to create a sufficient implementation of a ContextStackProvider.
static java.lang.Object	pop(java.util.List<java.lang.Object> stack) is a convenience method to help client actions to operate the List provided by the ContextStackProvider via DfaRun.clientData as a stack.
ContextManager	setDefaultAction(FaAction a) calls both, setDefaultStartAction() and setDefaultEndAction() with the given action.
ContextManager	setDefaultEndAction(FaAction a) defines the default action to be applied to the text matching a context end.
ContextManager	setDefaultFMB(DfaRun.FailedMatchBehaviour fmb) defines the default behaviour into which the DfaRun is switched, when a context is entered.
ContextManager	setDefaultStartAction(FaAction a) defines the default action to be applied to the text matching a context start.

Methods inherited from class java.lang.Object

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

Field Detail

anyContext

public static final Context anyContext

Constructor Detail

ContextManager

public ContextManager(Nfa nfa)

creates an object to populate the given Nfa with regex/action pairs for context matching.

Method Detail

setDefaultFMB

public ContextManager setDefaultFMB(DfaRun.FailedMatchBehaviour fmb)

defines the default behaviour into which the DfaRun is switched, when a context is entered. It defines how unmatched stretches of input shall be handled within the context. The default can be changed for individual Context objects with their setFMB() method.

Returns:

this

setDefaultStartAction

public ContextManager setDefaultStartAction(FaAction a)

defines the default action to be applied to the text matching a context start. The default can be changed for individual Context objects with their setStartAction() method. If this method is never called or is called with null, the context start text is copied to the output unchanged.

Returns:

this

See Also:

setDefaultAction(monq.jfa.FaAction)

setDefaultEndAction

public ContextManager setDefaultEndAction(FaAction a)

defines the default action to be applied to the text matching a context end. The comments to setDefaultStartAction() apply.

Returns:

this

See Also:

setDefaultAction(monq.jfa.FaAction)

setDefaultAction

public ContextManager setDefaultAction(FaAction a)

calls both, setDefaultStartAction() and setDefaultEndAction() with the given action.

Returns:

this

add

public Context add(Context parent,
                   java.lang.String reIn,
                   java.lang.String reOut)
            throws ReSyntaxException

adds a new context to the client Nfa. The context starts whenever the regular expression reIn matches while the given parent context is active. It ends as soon as reOut is found.

With parent==null, reIn will only switch to the new context from the outermost level, i.e. when no context was yet entered. Note that this is in line with IfContext() when called with null. If you want to match reIn to always match, independent of context, then use add(String,String).

The defaults of the context returned will be be initialized from the defaults stored in this with any of the setDefault... methods. They can be changed on the object returned as needed.

Parameters:

parent - may be null to denote the outermost level.

reIn - is the regular expression denoting the start of the new context being added to the client Nfa

reOut - is the regular expression denoting the end of the new context being added to the client Nfa

Returns:

the context just added to the client Nfa. You need the returned object to change its default behaviour and as a parent parameter for further calls to this method. Do not add the resulting context to any Nfa.

Throws:

ReSyntaxException

add

public Context add(java.lang.String reIn,
                   java.lang.String reOut)
            throws ReSyntaxException

calls add(Context,String,String) such that the context is entered in any parent context.

Throws:

ReSyntaxException

addXml

public Context addXml(Context parent,
                      java.lang.String tagname)
               throws ReSyntaxException

calls add(parent,reIn,reOut) such that reIn and reOut match the start and end of the XML element with the given tagname.

For the use of null as a parent, see add(Context,String,String).

Throws:

ReSyntaxException

addXml

public Context addXml(java.lang.String tagname)
               throws ReSyntaxException

calls add(Context,String,String) such that reIn and reOut match the start and end of the XML element with the given tagname.

Throws:

ReSyntaxException

addXml

public Context[] addXml(Context parent,
                        java.lang.String[] tagnames)
                 throws ReSyntaxException

creates a nested hierarchy of contexts defined by the XML tagnames given. The parent context for the element with tagname tagnames[0] will be the given parent. The context for further elements is always the previous context in the list.

Parameters:

parent - may be null.

Returns:

an array of contexts for the given tagnames.

Throws:

ReSyntaxException

addXml

public Context addXml()
               throws ReSyntaxException

calls add(Context,String,String) such that reIn and reOut match the start and end of any XML element.

Throws:

ReSyntaxException

pop

public static java.lang.Object pop(java.util.List<java.lang.Object> stack)

is a convenience method to help client actions to operate the List provided by the ContextStackProvider via DfaRun.clientData as a stack.

A push method is not provided because it would be a only an alias for List.add().

createStackProvider

public static java.lang.Object createStackProvider()

is a convenience method to create a sufficient implementation of a ContextStackProvider.