## com.saxonica.fsa
Class Edge

    java.lang.Object
      com.saxonica.fsa.Edge

    public class Edge

extends java.lang.Object

Internal class to represent the data associated with a transition: the element that triggers the transition, and the new state that results from the transition.

Nested Class Summary
`static class` `Edge.MaxOccursTerm` Special singular Term identifying a transition to be used when the maxOccurs value of a counting state is reached.

Constructor Summary
`Edge()`

Method Summary
`AutomatonState` `getTargetState()` Get the (fixed) state that is the target of this edge
`Term` `getTerm()` Get the element or wildcard particle causing this transition
`State` `makeTransition(State previousState)` Get the dynamic state that results from a transition using this edge, updating any counters that need to be updated
`java.lang.String` `matches(Edge de, SchemaCompiler compiler)` Test whether edges in two different finite state machines match each other.
`void` `serialize(SchemaModelSerializer serializer)` Serialize this Edge as part of the serialization of a schema component model
`void` `setTargetState(AutomatonState targetState)` Set the state resulting from this transition
`void` `setTerm(Term term)` Set the element or wildcard particle causing this transition

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### Edge

    public Edge()

Method Detail

### setTargetState

    public void setTargetState(AutomatonState targetState)

  Set the state resulting from this transition

  Parameters:
    `targetState` - the state at the end of this edge

### getTargetState

    public AutomatonState getTargetState()

  Get the (fixed) state that is the target of this edge

  Returns:
    the state at the end of this edge

### makeTransition

    public State makeTransition(State previousState)
                         throws ValidationException

  Get the dynamic state that results from a transition using this edge, updating any counters that need to be updated

  Parameters:
    `previousState` - the previous dynamic state before making this transition
  Returns:
    the dynamic state that results from applying this transition
  Throws:
    `ValidationException` - if this transition is not possible because the occurrence limits are violated

### setTerm

    public void setTerm(Term term)

  Set the element or wildcard particle causing this transition

  Parameters:
    `term` - the term that causes this transition

### getTerm

    public Term getTerm()

  Get the element or wildcard particle causing this transition

  Returns:
    the term that causes this transition

### matches

    public java.lang.String matches(Edge de,
                                    SchemaCompiler compiler)

  Test whether edges in two different finite state machines match each other. This is called while establishing whether one type subsumes another.

  From Thompson & Tobin 2003: an edge BE matches another edge DE iff one of the following three conditions holds: (1) they are labelled as element declarations with the same expanded name; (2) BE is labelled with a wildcard and DE is labelled with an element declaration in a namespace allowed by the wildcard; (3) BE and DE are both wildcards and DE's label is an intensional subset of BE's. In case (3) we add the rule, not in Thompson and Tobin, that the processContents of DE must be at least as strong as the processContents of BE.

  It is also necessary that the types of B and D are compatible, and that their nillability is compatible, and that their value constraints are compatible, and that the disallowed substitutions of D is a superset of those of B.

  Parameters:
    `de` - the edge in a finite state machine representing a derived type, and which corresponds to this edge in the finite state machine for the base type
    `compiler` - user for error reporting
  Returns:
    null if the edges match, or a string explaining the reason for the non-match if not.

### serialize

    public void serialize(SchemaModelSerializer serializer)
                   throws XPathException

  Serialize this Edge as part of the serialization of a schema component model

  Parameters:
    `serializer` - object that formats the model output
  Throws:
    `XPathException`

Copyright (c) Saxonica Limited. All rights reserved.