JFlex
Class NFA

java.lang.Object
  extended by JFlex.NFA

public final class NFA
extends java.lang.Object

NFA representation in JFlex. Contains algorithms RegExp -> NFA and NFA -> DFA.


Constructor Summary
NFA(int numInput, int estSize)
           
NFA(int numInput, LexScan scanner, RegExps regExps, Macros macros, CharClasses classes)
          Construct new NFA.
 
Method Summary
 void addEpsilonTransition(int start, int dest)
           
 void addRegExp(int regExpNum)
          Add a regexp to this NFA.
 void addStandaloneRule()
          Add a standalone rule that has minimum priority, fires a transition on all single input characters and has a "print yytext" action.
 void addTransition(int start, int input, int dest)
           
 java.lang.String dotFormat()
           
 void dumpTable()
           
 DFA getDFA()
          Returns an DFA that accepts the same language as this NFA.
 JFlex.IntPair insertNFA(RegExp regExp)
          Constructs an NFA for regExp such that the NFA has exactly one start state, exactly one end state, no transitions leading out of the end state no transitions leading into the start state
 int numEntryStates()
           
 java.lang.String toString()
           
 void writeDot(java.io.File file)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

NFA

public NFA(int numInput,
           int estSize)

NFA

public NFA(int numInput,
           LexScan scanner,
           RegExps regExps,
           Macros macros,
           CharClasses classes)
Construct new NFA. Assumes that lookahead cases and numbers are already resolved in RegExps.

See Also:
RegExps.checkLookAheads()
Method Detail

numEntryStates

public int numEntryStates()

addStandaloneRule

public void addStandaloneRule()
Add a standalone rule that has minimum priority, fires a transition on all single input characters and has a "print yytext" action.


addRegExp

public void addRegExp(int regExpNum)
Add a regexp to this NFA.

Parameters:
regExpNum - the number of the regexp to add.

addTransition

public void addTransition(int start,
                          int input,
                          int dest)

addEpsilonTransition

public void addEpsilonTransition(int start,
                                 int dest)

getDFA

public DFA getDFA()
Returns an DFA that accepts the same language as this NFA. This DFA is usually not minimal.


dumpTable

public void dumpTable()

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object

writeDot

public void writeDot(java.io.File file)

dotFormat

public java.lang.String dotFormat()

insertNFA

public JFlex.IntPair insertNFA(RegExp regExp)
Constructs an NFA for regExp such that the NFA has exactly one start state, exactly one end state, no transitions leading out of the end state no transitions leading into the start state

Parameters:
regExp - the regular expression to construct the NFA for
Returns:
a pair of integers denoting the index of start and end state of the NFA.