org.inxar.syntacs.automaton.finite
Interface DFA

All Known Implementing Classes:
TreeDFA, MesoArrayDFA

public interface DFA

The "Deterministic Finite Automaton" (DFA) interface abstracts a Moore state machine used to recognize discrete sequences of symbols (usually character symbols). More information about DFA's can be found pretty much anywhere, but chapter 3 of the Dragon Book is a good place to start.


Field Summary
static int DEAD_STATE
          The DEAD_STATE is the state where all exit paths lead back to the DEAD_STATE.
static int START_STATE
          Lexical analyzers or other tools should synchronize to the START_STATE constant upon initialization.
 
Method Summary
 int go(int state, int input)
          Returns the next state for the given state and given input symbol.
 int output(int state)
          Returns the output at the given state.
 

Field Detail

START_STATE

public static final int START_STATE
Lexical analyzers or other tools should synchronize to the START_STATE constant upon initialization.

DEAD_STATE

public static final int DEAD_STATE
The DEAD_STATE is the state where all exit paths lead back to the DEAD_STATE.
Method Detail

go

public int go(int state,
              int input)
Returns the next state for the given state and given input symbol.

output

public int output(int state)
Returns the output at the given state. Output values generally correspond to to Token ID numbers. If no output has been defined for the given state, Token.UNDEF is returned.