forgetest1
/
antlr
forked from jasder/antlr
1
0
Fork 0
Code Issues Pull Requests 1 Releases Wiki Activity

Add ATN representation for non-greedy decisions

This commit is contained in:
Sam Harwell 2012-10-14 16:34:58 -05:00
parent 9ea072aee0
commit 0d30a7a60b
4 changed files with 13 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
runtime/Java/src/org/antlr/v4/runtime/atn/ATNSimulator.java
View File

@ -262,9 +262,11 @@ public abstract class ATNSimulator {
int ndecisions = toInt(data[p++]);
for (int i=1; i<=ndecisions; i++) {
int s = toInt(data[p++]);
int nonGreedy = toInt(data[p++]);
DecisionState decState = (DecisionState)atn.states.get(s);
atn.decisionToState.add(decState);
decState.decision = i-1;
decState.nonGreedy = nonGreedy != 0;
}
verifyATN(atn);

1
runtime/Java/src/org/antlr/v4/runtime/atn/DecisionState.java
View File

@ -31,4 +31,5 @@ package org.antlr.v4.runtime.atn;
public class DecisionState extends ATNState {
public int decision = -1;
public boolean nonGreedy;
}

2
tool/src/org/antlr/v4/automata/ATNSerializer.java
View File

@ -226,6 +226,7 @@ public class ATNSerializer {
data.add(ndecisions);
for (DecisionState decStartState : atn.decisionToState) {
data.add(decStartState.stateNumber);
data.add(decStartState.nonGreedy ? 1 : 0);
}
return data;
}
@ -299,6 +300,7 @@ public class ATNSerializer {
int ndecisions = ATNSimulator.toInt(data[p++]);
for (int i=1; i<=ndecisions; i++) {
int s = ATNSimulator.toInt(data[p++]);
boolean nonGreedy = ATNSimulator.toInt(data[p++]) != 0;
buf.append(i-1).append(":").append(s).append("\n");
}
return buf.toString();

13
tool/src/org/antlr/v4/automata/ParserATNFactory.java
View File

@ -425,10 +425,11 @@ public class ParserATNFactory implements ATNFactory {
BlockStartState blkStart = (BlockStartState)blk.left;
BlockAST blkAST = (BlockAST)optAST.getChild(0);
if (isGreedy(blkAST)) {
blkStart.nonGreedy = !isGreedy(blkAST);
if (!blkStart.nonGreedy) {
epsilon(blkStart, blk.right);
}
else {
} else {
Transition existing = blkStart.removeTransition(0);
epsilon(blkStart, blk.right);
blkStart.addTransition(existing);
@ -463,7 +464,8 @@ public class ParserATNFactory implements ATNFactory {
epsilon(blkEnd, loop); // blk can see loop back
BlockAST blkAST = (BlockAST)plusAST.getChild(0);
if ( isGreedy(blkAST) ) {
loop.nonGreedy = !isGreedy(blkAST);
if ( !loop.nonGreedy ) {
epsilon(loop, blkStart); // loop back to start
epsilon(loop, end); // or exit
}
@ -502,7 +504,8 @@ public class ParserATNFactory implements ATNFactory {
end.loopBackState = loop;
BlockAST blkAST = (BlockAST)starAST.getChild(0);
if ( isGreedy(blkAST) ) {
entry.nonGreedy = !isGreedy(blkAST);
if ( !entry.nonGreedy ) {
epsilon(entry, blkStart); // loop enter edge (alt 1)
epsilon(entry, end); // bypass loop edge (alt 2)
}