mirror of
https://github.com/marcin-szczepanski/jFuzzyLogic.git
synced 2024-08-16 18:06:57 +02:00
260 lines
8.6 KiB
Java
260 lines
8.6 KiB
Java
/*
|
|
[The "BSD licence"]
|
|
Copyright (c) 2005-2006 Terence Parr
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
1. Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
2. Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
3. The name of the author may not be used to endorse or promote products
|
|
derived from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
package org.antlr.analysis;
|
|
|
|
import org.antlr.tool.GrammarAST;
|
|
import org.antlr.tool.Rule;
|
|
import org.antlr.tool.ErrorManager;
|
|
|
|
/** A state within an NFA. At most 2 transitions emanate from any NFA state. */
|
|
public class NFAState extends State {
|
|
// I need to distinguish between NFA decision states for (...)* and (...)+
|
|
// during NFA interpretation.
|
|
public static final int LOOPBACK = 1;
|
|
public static final int BLOCK_START = 2;
|
|
public static final int OPTIONAL_BLOCK_START = 3;
|
|
public static final int BYPASS = 4;
|
|
public static final int RIGHT_EDGE_OF_BLOCK = 5;
|
|
|
|
public static final int MAX_TRANSITIONS = 2;
|
|
|
|
/** How many transitions; 0, 1, or 2 transitions */
|
|
int numTransitions = 0;
|
|
public Transition[] transition = new Transition[MAX_TRANSITIONS];
|
|
|
|
/** For o-A->o type NFA tranitions, record the label that leads to this
|
|
* state. Useful for creating rich error messages when we find
|
|
* insufficiently (with preds) covered states.
|
|
*/
|
|
public Label incidentEdgeLabel;
|
|
|
|
/** Which NFA are we in? */
|
|
public NFA nfa = null;
|
|
|
|
/** What's its decision number from 1..n? */
|
|
protected int decisionNumber = 0;
|
|
|
|
/** Subrules (...)* and (...)+ have more than one decision point in
|
|
* the NFA created for them. They both have a loop-exit-or-stay-in
|
|
* decision node (the loop back node). They both have a normal
|
|
* alternative block decision node at the left edge. The (...)* is
|
|
* worse as it even has a bypass decision (2 alts: stay in or bypass)
|
|
* node at the extreme left edge. This is not how they get generated
|
|
* in code as a while-loop or whatever deals nicely with either. For
|
|
* error messages (where I need to print the nondeterministic alts)
|
|
* and for interpretation, I need to use the single DFA that is created
|
|
* (for efficiency) but interpret the results differently depending
|
|
* on which of the 2 or 3 decision states uses the DFA. For example,
|
|
* the DFA will always report alt n+1 as the exit branch for n real
|
|
* alts, so I need to translate that depending on the decision state.
|
|
*
|
|
* If decisionNumber>0 then this var tells you what kind of decision
|
|
* state it is.
|
|
*/
|
|
public int decisionStateType;
|
|
|
|
/** What rule do we live in? */
|
|
public Rule enclosingRule;
|
|
|
|
/** During debugging and for nondeterminism warnings, it's useful
|
|
* to know what relationship this node has to the original grammar.
|
|
* For example, "start of alt 1 of rule a".
|
|
*/
|
|
protected String description;
|
|
|
|
/** Associate this NFAState with the corresponding GrammarAST node
|
|
* from which this node was created. This is useful not only for
|
|
* associating the eventual lookahead DFA with the associated
|
|
* Grammar position, but also for providing users with
|
|
* nondeterminism warnings. Mainly used by decision states to
|
|
* report line:col info. Could also be used to track line:col
|
|
* for elements such as token refs.
|
|
*/
|
|
public GrammarAST associatedASTNode;
|
|
|
|
/** Is this state the sole target of an EOT transition? */
|
|
protected boolean EOTTargetState = false;
|
|
|
|
/** Jean Bovet needs in the GUI to know which state pairs correspond
|
|
* to the start/stop of a block.
|
|
*/
|
|
public int endOfBlockStateNumber = State.INVALID_STATE_NUMBER;
|
|
|
|
public NFAState(NFA nfa) {
|
|
this.nfa = nfa;
|
|
}
|
|
|
|
public int getNumberOfTransitions() {
|
|
return numTransitions;
|
|
}
|
|
|
|
public void addTransition(Transition e) {
|
|
if ( e==null ) {
|
|
throw new IllegalArgumentException("You can't add a null transition");
|
|
}
|
|
if ( numTransitions>transition.length ) {
|
|
throw new IllegalArgumentException("You can only have "+transition.length+" transitions");
|
|
}
|
|
if ( e!=null ) {
|
|
transition[numTransitions] = e;
|
|
numTransitions++;
|
|
// Set the "back pointer" of the target state so that it
|
|
// knows about the label of the incoming edge.
|
|
Label label = e.label;
|
|
if ( label.isAtom() || label.isSet() ) {
|
|
if ( ((NFAState)e.target).incidentEdgeLabel!=null ) {
|
|
ErrorManager.internalError("Clobbered incident edge");
|
|
}
|
|
((NFAState)e.target).incidentEdgeLabel = e.label;
|
|
}
|
|
}
|
|
}
|
|
|
|
/** Used during optimization to reset a state to have the (single)
|
|
* transition another state has.
|
|
*/
|
|
public void setTransition0(Transition e) {
|
|
if ( e==null ) {
|
|
throw new IllegalArgumentException("You can't use a solitary null transition");
|
|
}
|
|
transition[0] = e;
|
|
transition[1] = null;
|
|
numTransitions = 1;
|
|
}
|
|
|
|
public Transition transition(int i) {
|
|
return transition[i];
|
|
}
|
|
|
|
/** The DFA decision for this NFA decision state always has
|
|
* an exit path for loops as n+1 for n alts in the loop.
|
|
* That is really useful for displaying nondeterministic alts
|
|
* and so on, but for walking the NFA to get a sequence of edge
|
|
* labels or for actually parsing, we need to get the real alt
|
|
* number. The real alt number for exiting a loop is always 1
|
|
* as transition 0 points at the exit branch (we compute DFAs
|
|
* always for loops at the loopback state).
|
|
*
|
|
* For walking/parsing the loopback state:
|
|
* 1 2 3 display alt (for human consumption)
|
|
* 2 3 1 walk alt
|
|
*
|
|
* For walking the block start:
|
|
* 1 2 3 display alt
|
|
* 1 2 3
|
|
*
|
|
* For walking the bypass state of a (...)* loop:
|
|
* 1 2 3 display alt
|
|
* 1 1 2 all block alts map to entering loop exit means take bypass
|
|
*
|
|
* Non loop EBNF do not need to be translated; they are ignored by
|
|
* this method as decisionStateType==0.
|
|
*
|
|
* Return same alt if we can't translate.
|
|
*/
|
|
public int translateDisplayAltToWalkAlt(int displayAlt) {
|
|
NFAState nfaStart = this;
|
|
if ( decisionNumber==0 || decisionStateType==0 ) {
|
|
return displayAlt;
|
|
}
|
|
int walkAlt = 0;
|
|
// find the NFA loopback state associated with this DFA
|
|
// and count number of alts (all alt numbers are computed
|
|
// based upon the loopback's NFA state.
|
|
/*
|
|
DFA dfa = nfa.grammar.getLookaheadDFA(decisionNumber);
|
|
if ( dfa==null ) {
|
|
ErrorManager.internalError("can't get DFA for decision "+decisionNumber);
|
|
}
|
|
*/
|
|
int nAlts = nfa.grammar.getNumberOfAltsForDecisionNFA(nfaStart);
|
|
switch ( nfaStart.decisionStateType ) {
|
|
case LOOPBACK :
|
|
walkAlt = displayAlt % nAlts + 1; // rotate right mod 1..3
|
|
break;
|
|
case BLOCK_START :
|
|
case OPTIONAL_BLOCK_START :
|
|
walkAlt = displayAlt; // identity transformation
|
|
break;
|
|
case BYPASS :
|
|
if ( displayAlt == nAlts ) {
|
|
walkAlt = 2; // bypass
|
|
}
|
|
else {
|
|
walkAlt = 1; // any non exit branch alt predicts entering
|
|
}
|
|
break;
|
|
}
|
|
return walkAlt;
|
|
}
|
|
|
|
// Setter/Getters
|
|
|
|
/** What AST node is associated with this NFAState? When you
|
|
* set the AST node, I set the node to point back to this NFA state.
|
|
*/
|
|
public void setDecisionASTNode(GrammarAST decisionASTNode) {
|
|
decisionASTNode.setNFAStartState(this);
|
|
this.associatedASTNode = decisionASTNode;
|
|
}
|
|
|
|
public String getDescription() {
|
|
return description;
|
|
}
|
|
|
|
public void setDescription(String description) {
|
|
this.description = description;
|
|
}
|
|
|
|
public int getDecisionNumber() {
|
|
return decisionNumber;
|
|
}
|
|
|
|
public void setDecisionNumber(int decisionNumber) {
|
|
this.decisionNumber = decisionNumber;
|
|
}
|
|
|
|
public boolean isEOTTargetState() {
|
|
return EOTTargetState;
|
|
}
|
|
|
|
public void setEOTTargetState(boolean eot) {
|
|
EOTTargetState = eot;
|
|
}
|
|
|
|
public boolean isDecisionState() {
|
|
return decisionStateType>0;
|
|
}
|
|
|
|
public String toString() {
|
|
return String.valueOf(stateNumber);
|
|
}
|
|
|
|
}
|
|
|