PerCederberg.Grammatica.Runtime
Class NFAState

System.Object
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   +--NFAState

internal class NFAState

extends System.Object

An NFA state. The NFA consists of a series of states, each having zero or more transitions to other states.

epsilonOut

 internal bool epsilonOut;

The outgoing epsilon transitions flag.

incoming

 internal NFATransition[] incoming;

The incoming transitions to this state.

outgoing

 internal NFATransition[] outgoing;

The outgoing transitions from this state.

value

 internal TokenPattern value;

The optional state value (if it is a final state).

AddIn

public void AddIn( NFATransition trans );

Adds a new incoming transition.

Parameters:

trans - the transition to add

AddOut

public NFAState AddOut( char ch, bool ignoreCase, NFAState state );

Adds a new outgoing character transition. If the target state specified was null and an identical transition already exists, it will be reused and its target returned.

Parameters:

ch - he character to match

ignoreCase - the case-insensitive flag

state - the target state, or null

Returns:

the transition target state

AddOut

public NFAState AddOut( NFATransition trans );

Adds a new outgoing transition.

Parameters:

trans - the transition to add

Returns:

the transition target state

HasTransitions

public bool HasTransitions();

Checks if this state has any incoming or outgoing transitions.

Returns:

true if this state has transitions, or false otherwise

IsAsciiOutgoing

public bool IsAsciiOutgoing();

Checks if all outgoing transitions only match ASCII characters.

Returns:

true if all transitions are ASCII-only, or false otherwise

MatchEmpty

public void MatchEmpty( NFAStateQueue queue );

Adds all the epsilon transition targets to the specified queue.

Parameters:

queue - the state queue

MatchTransitions

public void MatchTransitions( char ch, NFAStateQueue queue, bool initial );

Attempts a match on each of the transitions leading from this state. If a match is found, its state will be added to the queue. If the initial match flag is set, epsilon transitions will also be matched (and their targets called recursively).

Parameters:

ch - the character to match

queue - the state queue

initial - the initial match flag

MergeInto

public void MergeInto( NFAState state );

Merges all the transitions in this state into another state.

Parameters:

state - the state to merge into