ANTLR 3.4 Release
July 18, 2011

Terence Parr, parrt at cs usfca edu
ANTLR project lead and supreme dictator for life
University of San Francisco

CHANGES

July 18, 2011 -- release 3.4

* Added tree method insertChild(int i, Object t).

July 14, 2011

* Added BaesTree.freshenParentAndChildIndexesDeeply() to recursively
  walk tree and set ptrs.

July 6, 2011

* reset() for token stream didn't skip initial off-channel tokens.

July 5, 2011

* Sam fixes rare infinite loop upon error in nextToken().
* rewrites weren't pulled from syntactic predicates.

June 29, 2011

* Sam noticed CommonToken.getText() cached substring pulled from input, which
  defeated purpose of pointing into input char array.  Altered to not cache.
  Should reduce memory footprint.

June 24, 2011

* empty alts with actions didn't have EPSILON dummy alt node.

June 19, 2011

* Udo noticed that Parser.getMissingSymbol() didn't set invented token's input

June 8, 2011

* Added inContext(String context) back into TreeParser.

April 21, 2011

* Updated for ST v4.0.2 (setting iterateAcrossValues = true as instance var)
* Needed throws condition for delegatedRules.

April 20, 2011 (Sam Harwell)

* Implement the 'throwsSpec' feature of parser rules for the Java target
* Improve algorithm for SemanticContext Boolean predicate reduction

April 13, 2011

* Unmangled region names in STViz hiearchy tree display.
* Removed conversion timeout thing again

April 11, 2011

* Added option -Xconversiontimeout back in.  Turns out we hit NFA conversion
  time landmine occasionally with huge grammars; fails over to backtracking
  (if turned on) if it can't make DFA.

March 29 - April 10, 2011

* Uses ST v4 now!!!  Massive change.  Only updated Java target so far.
  Ripped out ST v3 usage to remove indirect dependency on ANTLR v2.

March 28, 2011

* Sam Harwell ported all v2 grammars to v3!

March 3, 2011

* left-recursion pattern off until all targets catch up

* ANTLRCore.sti no longer used; removed from all targets.

* Adding type, text terminal options

* Replaced hetero arg with terminalOptions arg in all templates that reference hetero
  (this is the class name / node type used for TOKEN<NODETYPE> references
  in grammar).  Widespread but trivial changes to all targets.  hetero is
  now terminalOptions.node.  Can also get terminalOptions.type and
  terminalOptions.text from dictionary of options.

* Fixed mispelling of license in BSD license headers

March 3, 2011

* Add tree, getTree() to ParserRuleReturnScope to do away with specific ones like:
    public static class rewrite_template_args_return extends ParserRuleReturnScope {
        CommonTree tree;
        public Object getTree() { return tree; }
    };
  Removed these special classes if it's just AST; keep if they have defined "returns"
  values

February 26, 2011

* All finally {} have comment now to suppress warning.

* removed ; from {;} blank method

* Added @SuppressWarnings({"all"}) to front of each
  generated class.

* -print wasn't always showing ^ and ! in grammar

* Added java-left-recur/Java.g example.

* left-recursion pattern detection handles backtracking mode now

February 25, 2011

* -Xmaxinlinedfastates went to 60 from 10 for forcing prediction in left-
  recursive expression rules to stay in rule; preds use a parameter.

* trees know where they came from now start..stop tokens; todo: use for better err handling.

* Got immediate left-recursion working for rules. Added TestLeftRecursion.java

February 21, 2011

* Fixed http://www.antlr.org/jira/browse/ANTLR-437 thanks to Vladislav Kuzkokov.
  added unit test.

February 17, 2011

* Add -language L option to override language=L option in grammar.  Same
  grammar can yield multiple parsers in different languages now.

February 10, 2011

* Added method to generated Java code to return the array of delegates; e.g.,
    import Sub1, Sub2;
  yields:

    public Parser[] getDelegates() {
        return new Parser[] {gSub1, gSub2};
    }

January 25, 2011

* Improve error messages for no viable alt parse exceptions

January 20, 2011

* TokenRewriteStream had dead code; also updated insertBefore followed by
  replace or delete.  If input is abc and I did insertBefore(2,"y"), where
  'c' is index 2, then did delete of 2 previously defined functionality
  was to ignore the insert. that's weird; fixed to keep insert.  Also
  Delete special case of replace (text==null):
  	  D.i-j.u D.x-y.v	| boundaries overlap => combine to max(min)..max(right)

December 12, 2010

* Send couldBacktrack now to enterDecision in debug protocol

December 4, 2010

* TreeWizard ctor needed a default tree adapator.

November 29, 2010 -- ANTLR v3.3

November 23, 2010

* CodeGenerator.loadLanguageTarget is now static and available to load
  targets so we can ask them questions during analysis.

* Fixed and added unit test
    http://www.antlr.org/jira/browse/ANTLR-370
    http://www.antlr.org/jira/browse/ANTLR-375

November 23, 2010

* Added source name to syntax error msgs

October 20, 2010

Added boolean couldBacktrack to enterDecision in dbg interface. Breaks AW
interface and other tools! [BREAKS BACKWARD COMPATIBILITY]

October 17, 2010

* Missing -trace in help msg

November 22, 2010

* Added GrammarAST: public int getCharPositionInLine() { return getColumn()-1; }
  and Grammar.getHasDelegates() for C# guys

October 16, 2010

* Doesn't write profile data to file anymore; emits decision data to stderr

October 14, 2010

* Make OrderedHashSet have deterministic iteration

July 20, 2010

* greedy=true option shuts off nondeterminism warning.

* code gen for AST and -profile didn't compile. had useless line:

             proxy.setTreeAdaptor(adap);


July 17, 2010

* Removed conversion timeout failsafe; no longer needed.

* Stats updated to be correct for -report.

June 10, 2010

* added toArray in OrderedHashSet to make addAll calls get same order for DFA edges and possibly code gen in some areas.

June 5, 2010

* Added -Xsavelexer

May 24, 2010

* lexerStringRef was missing elementIndex attribute. i='import' didn't work
  in lexer.  Altered all target stg files.  Set in codegen.g

* output=AST, rewrite=true for tree rewriters broken. nextNode for subtree
  streams didn't dup node, it gave whole tree back.

March 17, 2010

* Added MachineProbe class to make it easier to highlight ambig paths in
  grammar.  More accurate than DecisionProbe; retrofitted from v4.

February 20, 2010

* added range to TokenStream and implementors:
    /** How far ahead has the stream been asked to look?  The return
     *  value is a valid index from 0..n-1.
     */
    int range();

* added new method to get subset of tokens to buffered token streams:
	public List get(int start, int stop);

February 15, 2010

* Refs to other tokens in a lexer rule didn't get its line/charpos right.
  altered Java.stg.

January 31, 2010

* Creating token from another token didn't copy input stream in CommonToken.
  makes sense to copy too; i don't think anybody relies on it being null after
  a copy. We might want to know where token came from.

January 26, 2009

* TreeParser.getMissingSymbol() use CommonTree instead of using
  adaptor.create()

December 8, 2009

* Instead of sharing Token.EOF_TOKEN, I'm now creating EOF tokens so I can set the char position for better error messages.

December 5, 2009

* Fixed bug in TreeVisitor when rewrites altered number of children. Thanks to Chris DiGiano.

* added new buffered on-demand streams: BufferedTokenStream. Renamed CommonTokenStream to LegacyCommonTokenStream and made new one as subclass of BufferedTokenStream.

November 3, 2009

* Added org.antlr.runtime.UnbufferedTokenStream. Was trivial and works!

November 1, 2009

* Couldn't properly reuse parser state; ctor reset the state; fixed.
	Parser(TokenStream input, RecognizerSharedState state)

* LookaheadStream<T> used some hardcoded Object return types for LT, etc...
  uses T now.

September 23, 2009 -- ANTLR v3.2

September 21, 2009 [Jim Idle]

* Added new options for tool invocation to control the points at which the code
  generator tells the target code to use its equivalent of switch() instead of
  inline ifs.
      -Xmaxswitchcaselabels m don't generate switch() statements for dfas
                              bigger  than m [300]
      -Xminswitchalts m       don't generate switch() statements for dfas smaller
                              than m [3]
* Upgraded -X help output to include new optins and provide the default
  settings, as well as provide units for those settings that need them.

* Change the C Target to overide the deafults for the new settings to
  generate the most optimizable C code from the modern C compiler point of
  view. This is essentially to always use swtich statements unless there
  is absolutely no other option. C defaults are to use 1 for minimum and
  3000 for maximum number of alts that trigger switch(). This results in
  object code that is 30% smaller and up to 20% faster.

April 23, 2009

* Added reset to TreeNodeStream interface.

April 22, 2009

* Fixed ANTLR-374.  Was caused by moved of grammars. %foo() stuff didn't work

April 9, 2009

* .g and .g3 file extensions work again.
* introduced bug in 3.1.3: gives exception not error msg upon
  missing .g file

March 26, 2009

* Made ctor in TreeRewriter and TreeFilter call this not super.

March 21, 2009

* Added ctor to RecognizerSharedState to allow cloning it.

March 17, 2009 -- ANTLR v3.1.3

* improved ANTLRv3.g to handle <...> element options

March 15, 2009

* Fixed ANTLR-389. Strip didn't ignore options in subrules; also seemed
  to demand stdin.

March 15, 2009

* ANTLR always sorts incoming grammar list by dependency.  For example,
  If W.g depends on tokens from P.g then P.g is done first even if
  W.g mentioned first on command line.  It does not ignore any files you
  specify the commandline.  If you do *.g and that includes some
  imported grammars, it will run antlr on them.

* -make option prevents ANTLR from running on P.g if P older than
  generated files.

* Added org.antlr.tool.GrammarSpelunker to build a faster dependency
  checker (what grammars depend on etc...).  Totally independent of any
  ANTLR code; easy to pull into other tools.

* Added org.antlr.misc.Graph, a general graph with nodes
  containing an Object payload. It knows how to do a topological sort
  on the nodes.

March 10, 2009

* Added associativity token option to support upcoming special expression
  parsing. Added rule option strategy=precedence also

March 1, 2009

* Changed ANTLRWorks debug port from 49153 to 49100.  Apparently we change the port in
  ANTLRWorks to 49100 in 1.2 but forgot to do so in the ANTLR targets.

START CHANGES FOR TREE FILTER MODE (pulled from dev branch)

This feature will be announced in 3.2, but I am integrating from my development branch now into the mainline so target developers have a chance to implement. We might release 3.1.3 bug fix release before 3.2.

* CommonTreeNodeStream -> BufferedTreeNodeStream.  Now,
  CommonTreeNodeStream is completely unbuffered unless you are
  backtracking.  No longer making a list of all nodes before tree parsing.

* Added tree grammar filter=true mode.

  Altered templates:
	Java.stg: added filterMode to genericParser and treeParser.
	This required a change to ANTLRCore.sti
	Defined a default parameter in treeParser to set the superclass
	to TreeFilter for tree grammar with filter=true. It sets
	superclass to TreeRewriter if filter=true and output=AST.
  Other them that, I only had to change ANTLR itself a little bit.
  Made filter mode valid for tree grammars and have it automatically set
  the necessary elements: @synpredgate, backtrack=true, rewrite=true
  (if output=AST).  Added error message for detecting conflicting
  options.

* Added misc.FastQueue and TestFastQueue:
  A queue that can dequeue and get(i) in O(1) and grow arbitrarily large.
  A linked list is fast at dequeue but slow at get(i).  An array is
  the reverse.  This is O(1) for both operations.

* Added tree.TreeIterator, a generator that walks a doubly linked tree.
  The nodes must know what index they are. It's an Iterator but
  remove() is not supported. Returns navigation nodes always:
  UP, DOWN, EOF.

* Added misc.LookaheadStream: A lookahead queue that knows how
  to mark/release locations in the buffer for backtracking purposes.
  I hope to use for both tree nodes and tokens.  Just implement
  nextElement() to say how to get next node or token.

END CHANGES FOR TREE FILTER MODE

February 23, 2009 -- ANTLR v3.1.2

February 18, 2009

* Added org.antlr.tool.Strip (reads from file arg or stdin, emits to stdout)
  to strip actions from a grammar.

February 4, 2009

* Added CommonTree.setUnknownTokenBoundaries().  Sometimes we build trees
  in a grammar and some of the token boundaries are not set properly.
  This only matters if you want to print out the original text associated
  with a subtree.  Check this out rule:

	postfixExpression
	    :   primary ('.'^ ID)*
	    ;

  For a.b.c, we get a '.' that does not have the token boundaries set.
  ANTLR only sets token boundaries for subtrees returned from a rule.
  SO, the overall '.' operator has the token boundaries set from 'a'
  to 'c' tokens, but the lower '.' subtree does not get the boundaries
  set (they are -1,-1).  Calling setUnknownTokenBoundaries() on
  the returned tree sets the boundaries appropriately according to the
  children's token boundaries.

January 22, 2009

* fixed to be listeners.add(listener); in addListener() of DebugEventHub.java

January 20, 2009

* Removed runtime method: mismatch in BaseRecognizer and TreeParser.  Seems
  to be unused.  Had to override method recoverFromMismatchedToken() in
  TreeParser to get rid of single token insertion and deletion for
  tree parsing because it makes no sense with all of the up-and-down nodes.

* Changed JIRA port number from 8888 to no port spec (aka port 80) and all
  refs to it in this file.

* Changed BaseTree to Tree typecase in getChild and toStringTree() and
  deleteChild() to make more generic.

December 16, 2008

* Added -verbose cmd-line option and turned off standard header
  and list of read files.  Silent now without -verbose.

November 24, 2008

* null-ptr protected getParent and a few others.

* Added new ctor to CommonTreeNodeStream for walking subtrees.  Avoids
  having to make new serialized stream as it can reuse overall node stream
  buffer.

November 20, 2008

* Updated BaseTest to isolate tests better.

November 17, 2008

* BaseTreeAdaptor.getType() was hosed; always gave 0.  Thanks to Sam Harwell.

November 8, 2008

* Added methods to BaseRecognizer:
  public void setBacktrackingLevel(int n) { state.backtracking = n; }
  /** Return whether or not a backtracking attempt failed. */
  public boolean failed() { return state.failed; }

November 5, 2008

* Tweaked traceIn/Out to say "fail/succeeded"

* Bug in code gen for tree grammar wildcard list label x+=.

* Use of backtrack=true anywhere in grammar causes backtracking sensitive
  code to be generated.  Actions are gated etc...  Previously, that only
  happened when a syntactic predicate appeared in a DFA.  But, we need
  to gate actions when backtracking option is set even if no decision
  is generated to support filtering of trees.

October 25, 2008

* Fixed debug event socket protocol to allow spaces in filenames.

* Added TreeVisitor and TreeVisitorAction to org.antlr.runtime.tree.

October 22, 2008

* Added inContext() to TreeParser.  Very useful for predicating
  tree grammar productions according to context (their parent list).
  Added new TestTreeContext unit tests (15).

    /** Check if current node in input has a context.  Context means sequence
     *  of nodes towards root of tree.  For example, you might say context
     *  is "MULT" which means my parent must be MULT.  "CLASS VARDEF" says
     *  current node must be child of a VARDEF and whose parent is a CLASS node.
     *  You can use "..." to mean zero-or-more nodes.  "METHOD ... VARDEF"
     *  means my parent is VARDEF and somewhere above that is a METHOD node.
     *  The first node in the context is not necessarily the root.  The context
     *  matcher stops matching and returns true when it runs out of context.
     *  There is no way to force the first node to be the root.
     */
    public boolean inContext(String context) {...}

* Added 3 methods to Tree interface [BREAKS BACKWARD COMPATIBILITY]

    /** Is there is a node above with token type ttype? */
    public boolean hasAncestor(int ttype);

    /** Walk upwards and get first ancestor with this token type. */
    public Tree getAncestor(int ttype);

    /** Return a list of all ancestors of this node.  The first node of
     *  list is the root and the last is the parent of this node.
     */
    public List getAncestors();

October 21, 2008

* Updated unit tests to be correct for \uFFFE->\uFFFF change

* Made . in tree grammar look like ^(. .*) to analysis, though ^(. foo)
  is illegal (can't have . at root). Wildcard is subtree or node.
  Fixed bugs:
    http://www.antlr.org/browse/ANTLR-248
    http://www.antlr.org/browse/ANTLR-344

October 1, 2008 -- ANTLR v3.1.1

September 8, 2008

* Labels on tokens, rules carry into synpreds now so semantic predicates work.
  This didn't work since labels were stripped in the synpred and they weren't
  defined in the generated method.

  a : x=A z=a {$x.text.equals($z.text)}? A
    | y=A a A A
    ;

September 3, 2008

* Made a REV static variable in Tool so that we can change the rev for
  daily builds.

* Made \uFFFF a valid character. Token types are 32-bit clean using -1
  not 0x0000FFFF as -1 so it should be okay.  Label.java:
    public static final int MIN_CHAR_VALUE = '\u0000';
    public static final int MAX_CHAR_VALUE = '\uFFFF';

August 30, 2008

* Changed messages in en.stg so that TOKEN_NONDETERMINISM correctly
  indicates when actions hid semantic predicates.

August 15, 2008

* Tweaked build properties and build.xml

August 13, 2008

* Fixed ANTLR-314; 3.1 introduced a problem with list labels +=

August 12, 2008 -- ANTLR v3.1

* Added JavaScript target

August 7, 2008

* an NFA target of EOF predicate transition in DFA cause an exception in
  getPredicatesPerNonDeterministicAlt().

* Kay Roepke found a nasty bug when debugging AST-constructing
  composite recognizers.  If the input state was null to the constructor,
  super class constructor created a new parser state object.
  Later, though we passed the argument state not this.state
  to the delegate constructors, forcing them to share a different
  state objects!  Changed state to this.state in Dbg.stg constructors.

* Ack. messed up debug/AST.  Have to set proxy's tree adaptor; it's
  a circular ref.  Just an ASTDbg.stg change.

August 4, 2008

* superClass works now for lexers

* Made Grammar.defineNamedAction propogate header actions down to all
  delegates if root grammar; regardless of lexer/parser scope.

* Rejiggered AST templates to propogate changes to tree adaptor
  for delegate grammars. Fixes ANTLR-302

August 4, 2008

* FOLLOW set computations altered constant FOLLOW bit sets.

* Added (...) are all predicate evaluations.

* Extra init code for tree parser nonrewrite mode removed.

* Added empty child list check in becomeRoot

August 3, 2008

* Was using RuleReturnScope not Rulename_return for list labels in tree
  parser.

* Didn't set _last in tree parser for rule ref track stuff (rewrite=true)

August 2, 2008

* Benjamin found another rewrite engine bug.

July 30, 2008

* CommonTreeNodeStream / CommonTokenStream did not reset properly.

July 29, 2008

* Fixed another bug in TokenRewriteStream; didn't like inserts after end.

July 28, 2008

* Fixed bug in TokenRewriteStream.toString(start,stop); it ignored
  parameters. ;)

July 17, 2008

* allow qualified type names in hetero <...> options like T<a.b.c.Node>

July 5, 2008

* treeLevel not set for setBlock alts; added unit test

July 3, 2008

* Fixed ANTLR-267. parse tree added nodes during backtracking and
  cyclic DFAs.  tracks hidden tokens too now. Added toInputString() to
  get text back including hidden tokens.  Shows <epsilon> for rules
  that match nothing.

June 26, 2008

* Added gParent ptr that points to immediate parent grammar. E.g.,
    // delegators
    public MParser gM;
    public M_S gS;
    public M_S gParent = gS; // NEW

* Grammar imports didn't set all the delegate pointers...lots of imported
  grammars would cause a null ptr exception.  Fixes ANTLR-292.

June 25, 2008

* List labels in tree construction didn't always track the tree; sometimes
  had a rule result structure.

June 4, 2008

* Improved unit testing so that each test suite executes and builds grammars
  in a separate temporary directory. This means they can execute concurrently.
  Also seem to be a problem with my class path during execution. Moved
  tmpdir for ahead of standard CLASSPATH.

* By virtue of an improvement to StringTemplate, output newlines
  in generated files should be normalized to whatever your host uses.

June 3, 2008

* Restrict legality of grammar options; for example you cannot use output option
  in lexer anymore.

June 2, 2008

* Throw illegal arg exception upon invalid TokenRewriteStream ops. Rewrote
  core of engine.  Slightly different operation.  Added many more unit tests.

3.1b1 - May 20, 2008

May 11, 2008

* rewrite=true, output=AST for tree grammar was not working.  Altered trees were not
  propagated back up the rule reference chain.  Required a number of mods to
  ASTTreeParser.stg.  Added unit tests.

May 10, 2008

* [BACKWARD INCOMPATIBLE if you override match()]
  I had turned off single token insertion and deletion because I could not figure
  out how to work with trees and actions. Figure that out and so I turned it back on.
  match() returns Object matched now (parser, tree parser) so we can set labels
  on token refs properly after single token ins/del error recovery.  Allows actions
  and tree construction to proceed normally even though we recover in the middle of
  an alternative.  Added methods for conjuring up missing symbols: getMissingSymbol().

* refactored BaseRecognizer error handling routines

* Single token error recovery was not properly taking into consideration EOF.

* ANTLR no longer tries to recover in tree parsers inline using single node deletion or insertion; throw exception.  Trees should be well formed as they are not created by users.

* Added empty constructors to the exception classes that did not have them so that ANTLRWorks can create the exceptions.

* Made debug tree adaptor deal with tokens conjured up during error recovery.

* Removed extra location() debug element that was emitted.

May 8, 2008

* ANTLR didn't update line/col to DFA map for AW.

May 6-7, 2008

* Insufficiently covered (with semantic predicates) alt warnings are now emitted before
  nondeterminisms so it's clear the nondeterminism is a result of insufficient preds.

* Improved insufficiently covered alt warnings from:
    warning(203): T.g:2:3: The following alternatives are insufficiently covered with predicates: 1
  to:
    warning(203): T.g:2:3: Input B is insufficiently covered with predicates at loca
tions: alt 1: line 3:15, alt 2: line 2:9

* Improved nondeterminism warning to have:
  Semantic predicates were present but were hidden by actions.
parser grammar U;
a : (A B)? ;
b : X a {p1}? A B | Y a {a1} {p2}? A B | Z a ;

To create the prediction DFA for the optional sub rule in 'a', ANTLR must find all references to 'a' to determine what can follow. A B can follow 'a' in the first two alts rule 'b'.   To resolve the conflict between matching A B immediately in the sub rule and exiting rule 'a' to match it in 'b', ANTLR looks for predicates. In this case, there are two predicates that indicate the semantic context in which the surrounding alternatives are valid. The problem is that one of the predicates is hidden by an action. It took me 1.5 days, but I've finally have gotten ANTLR to properly track the insufficiently covered alternatives. Further, I have gotten it to tell you precisely where the uncovered predicates are even if they are simply hidden by actions. I have also updated all of the nondeterminism warnings so that it tells you if there was a predicate but one hidden by an action (this could be a separate condition from insufficiently covered predicates). here are your messages from ANTLR:

ANTLR Parser Generator  Version 3.1b1 (??)  1989-2007
warning(203): U.g:2:5: Input such as "A B" is insufficiently covered with predicates at locations: alt 2: line 3:38 at B
Semantic predicates were present but were hidden by actions.
warning(200): U.g:2:5: Decision can match input such as "A B" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Semantic predicates were present but were hidden by actions.

* Fixed issue where
r41
   : (INT -> INT) ( ('+' i=INT) -> ^($i $r41) )* ';'
   ;
still warned about $r41 being ambig.

* actions are now added to the NFA.

* Fixed ANTLR-222.  ANTLR now ignores preds after actions.

May 5, 2008

* Fixed ANTLR-235 by backing out a change from 12-31-07.

* Fixed ANTLR-249; I include semantic context again in closure busy signal.

May 3, 2008

* Fixed ANTLR-208.  Looks in library or in -o output path.  antlr -o foo T.g U.g where U needs T.tokens won't work unless we look in foo too.  fixed.

* Refactored assign.types.g to move methods to a class called AssignTokenTypesBehavior.

* Fixed ANTLR-207.  Lexers importing vocabs didn't see ';'=4 type aliases in .tokens.

* Fixed ANTLR-228.  Couldn't use wildcard in alts with AST rewrites.

May 2, 2008

* Fixed ANTLR-230; can use \' now in action.

* Scope attributes no longer have a stack depth check on front.  If you ref $r::a when r has not invoked you, then you get an exception not a default value.  Back to the way 3.0.1 worked.

* $channel was a global variable in 3.0.1 unlike $type which did not affect an invoking lexer rule.  Now it's local too.  Only $type and $channel are ever set with regularity.  Setting those should not affect an invoking lexer rule as in the following should work:

  X : ID WS? '=' ID ;  // result is X on normal channel
  WS : ' '+ {$channel = HIDDEN; } ;

  STRING : '"' (ESC|.)* '"' ;  // result is STRING not ESC

  FLOAT : INT '.' INT? ; // should be FLOAT
  INT : Digit+ ;
  fragment
  Digit : '0'..'9' ;

* Fixed bug in interpreter regarding (...)* loops

May 1, 2008

* Fixed ANTLR-202.  These now give warnings about ambig ref to $a.
    a : ID a -> $a | INT ;
  and
    a : A a {$a.text} | B ;

April 30, 2008

* Fixed ANTLR-237. updated -depend to know about imported grammars.
$ java org.antlr.Tool -depend -lib foo T.g
  ANTLR Parser Generator  Version 3.1b1 (??)  1989-2007
  T.g: foo/Java.g
  TParser.java : T.g
  T.tokens : T.g
  TLexer.java : T.g
  T_Java : T.g

April 29, 2008

* Fixed ANTLR-217; scope A,B,C; didn't work

* Fixed ANTLR-224; ! or ^ on item in alt with rewrite gave exception

* Added token options to terminals: ID<node=V; foo="Big bob"> etc...
  node is default so you can do ID<V> for hetero tree types. most common.

April 17, 2008

* Use default msg if unknown recog type in getErrorMessage():
	String msg = e.getMessage();

April 14, 2008

* %x.y = foo; was not working in @members section

March 29, 2008

* Import couldn't handle A imports B imports C.

March 27, 2008

* Added get/setInputStream to Token interface and affected classes.

February 26, 2008

* made fillBuffer public in CommonTreeNodeStream so we can add trees
  to stream for interactive interpreters.

February 14, 2008

* Fixed a bug in the code generation where tree level 0 was used
  no matter what to rewrite trees in tree grammars. added unit test

* Fixed ANTLR-221. exceptions were generated when using
  AST construction operators and no output=AST option.

February 13, 2008

* Improved error msgs for unreachable alts and tokens.

February 11-12, 2008

* Fixed ANTLR-219.
  It looks like the AST construction code for sets was totally messed up.
  This was for not only the new tree parser AST construction, but also
  the regular tree construction for parsers. I had to introduce templates
  in the ASTTreeParser.stg file to deal with this. added unit tests:
  TestTreeGrammarRewriteAST.testSetMatchNoRewrite(),
  testSetMatchNoRewriteLevel2(), testSetMatchNoRewriteLevel2Root().
  Had to add template matchRuleBlockSet()
  to differentiate between a regular set in one that is an entire rule.
  If it is an entire rule, it has to set the return value, retval.tree.

* Fixed ANTLR-220.
  Made TreeAdaptor dupNode and dupTree events emit debugging events
  so AW could see tree node duplications.

February 4, 2008

* BACKWARD INCOMPATIBILITY
  Added getSourceName to IntStream and TokenSource interfaces and also the
  BaseRecognizer.  Have to know where char come from for error messages.
  Widespread change, but a trivial one.

January 17, 2008

* Interpreter throws FailedPredicateException now when it sees a predicate;
  before it was silently failing.  I'll make it work one of these days. ;)

January 12, 2008

* Copy ctor not copying start and stop for common token. Fixes ANTLR-212

* Removed single token insertion and deletion for tokens, sets.
  Required a change to the code generation for matchSet() template
  and a tweak inside the BaseRecognizer.  To engage this again is easy,
  just override mismatch() to call mismatchRecover(). I changed it to simply
  throw an exception.

* Added syntaxError recognizer state var so you can easily tell if
  a recognizer failed.  Added getNumberOfSyntaxErrors() to recognizers.

* Added doc for the error node stuff:
  http://www.antlr.org/wiki/display/ANTLR3/Tree+construction

* Fixed ANTLR-193

* Added recognizer methods to answer questions about current mismatched
  token error.  Useful now since i don't automatically recover inline
  to such errors (I throw exception):
	mismatchIsUnwantedToken(IntStream input, int ttype)
	mismatchIsMissingToken(IntStream input, BitSet follow)

* Added UnwantedTokenException and MissingTokenException to make
  match() problems more precise in case you want to catch differently.
  Updated getErrorMessage() to be more precise.  Says:

	line 2:9 missing EQ at '0'

  now instead of

	line 2:9 mismatched input '0' expecting EQ

  Input "x=9 9;" gives

	line 3:8 extraneous input '9' expecting ';'

  When very confused, "x=9 for;", you still get old mismatched message:

	line 3:8 extraneous input 'for' expecting ';'
	line 3:11 mismatched input ';' expecting '('

* Added unit tests to TestAutoAST and copied to TestRewriteAST with
  suitable rewrites to ensure basic error node insertion works.

January 11, 2008

* Adding errorNode to TreeAdaptor and various debug
  events/listeners.  Had to add new class runtime.tree.CommonErrorNode
  to hold all the goodies: input stream, start/stop objects.

* Tweaked CommonTree.getType() to return INVALID_TOKEN_TYPE
  instead of literal 0 (same thing at moment though).

* Updated ANTLRWorks to show error nodes in tree as much as I could; Jean
  will get to rest of it.

January 9-10, 2008

* Continued work on debugging/profiling composite grammars.

* Updated debug protocol for debugging composite grammars.  enter/exit
  rule needs grammar to know when to flip display in AW.

* Fixed ANTLR-209.  ANTLR consumed 2 not 1 char to recover in lexer.

* Added two faqs instead of making changes to antlr runtime about
  lexer error handling:
  http://www.antlr.org/wiki/pages/viewpage.action?pageId=5341230
  http://www.antlr.org/wiki/pages/viewpage.action?pageId=5341217

January 1-8, 2008

* Making debugging/profiling work with composite grammars.

* Updated ANTLRWorks so it works still for noncomposite grammars.

* two new examples: import and composite-java (the java example grammar
  broken up into multiple pieces using import).

* Worked on composite grammars.  Had to refactor a lot of code to make
  ANTLR deal with one meta grammar made up of multiple grammars.  I
  thought I had it sort of working back in August.  Yes, but barely. Lots
  of work to do it seemed.  Lots of clean up work.  Many new unit tests
  in TestCompositeGrammars.  Had to add new error messages warning about
  conflicting tokens inherited from multiple grammars etc...

    TOKEN_ALIAS_CONFLICT(arg,arg2) ::=
      "cannot alias <arg>; string already assigned to <arg2>"
    TOKEN_ALIAS_REASSIGNMENT(arg,arg2) ::=
      "cannot alias <arg>; token name already assigned to <arg2>"
    TOKEN_VOCAB_IN_DELEGATE(arg,arg2) ::=
      "tokenVocab option ignored in imported grammar <arg>"
    INVALID_IMPORT(arg,arg2) ::=
      "<arg.grammarTypeString> grammar <arg.name> cannot import <arg2.grammarTypeString> grammar <arg2.name>"
    IMPORTED_TOKENS_RULE_EMPTY(arg,arg2) ::=
      "no lexer rules contributed to <arg> from imported grammar <arg2>"
    IMPORT_NAME_CLASH(arg,arg2) ::=
      "combined grammar <arg.name> and imported <arg2.grammarTypeString> grammar <arg2.name> both generate <arg2.recognizerName>; import ignored"

  This stuff got really really complicated.  Syntactic predicate names even
  had to be scoped per grammar so they don't conflict.

* When using subrules like (atom->atom) to set result tree, it was not
  properly setting result (early enough).  Future code got null for
  $rule.tree.

December 31, 2007

* Added the start of a semantic predicate computation for LL(1) to
  solve a problem with slow grammar analysis even with k=1 due to
  predicates.  Then I realized the problem with that grammar was
  elsewhere.  Semantic context really shouldn't be used when
  preventing closure recomputation (May 2008 I discovered I was
  wrong--you do need it).  The predicates became huge even though the
  reduced value would be no different.  The analyzer seems faster now
  that I am not testing predicate values all the time.  Further it may
  terminate sooner just due to reduced closure recursion.

* Moved FIRST/FOLLOW computations to a separate class LL1Analyzer to
  tidy up.

* ANTLR lexer allowed octal escapes, but they didn't work. ;)  Rather than
  fix, I'm removing.  Use '\uxxxx' to get even 8 bit char values: \u00xx.

December 29, 2007

* Fixed ANTLR-206. I wasn't avoiding analyzing decisions in
  left-recursive rules.

* Had to add hetero arg to all tokenRef*() templates.  Added _last
  local var to track last child so we can do replaceChildren() during
  AST rewrite mode for tree grammars.  Should be useful later for .text
  property.  Ack, hetero arg is on lots of templates. :(  Moved
  ruleCleanUp() template into ASTTreeParser and ASTParser groups.

* added noRewrite() template (to Java.stg) so we can insert code during
  rewrite mode to return original tree if no rewrite.  Might be useful
  for token rewrites later.  For templates too?

* Had to add if !rewriteMode around tree construction in tree parser
  templates.

* Harald Muller pointed out that we need to use <initValue(attr.type)>
  in our tests for null token/rule property references. For int types
  we need 0 not null. (p!=null?p.line:0).  Changed scopeAttributeRef,
  ruleLabelRef.  Also changed the known typed attributes like
  lexerRuleLabelPropertyRef_line to yield 0 upon null rule ref to
  be consistent with case when we don't know the type.  Fixes ANTLR-195.
  Added testTypeOfGuardedAttributeRefIsCorrect test and reset expected
  output for 13 tests that now "fail".

December 28, 2007

* added polydiff example (Java target)

* added "int" property for token and lexer rule refs.  super convenient. E.g.,
  a : b=INT {int x = $b.int;} ;

December 27, 2007

* Changed -Xnoinlinedfa to -Xmaxinlinedfastates m where m is
  maximum number of states a DFA can have before ANTLR avoids
  inlining it.  Instead, you get a table-based DFA.  This
  affectively avoids some acyclic DFA that still have many states
  with multiple incident edges.  The combinatorial explosion smacks
  of infinite loop.  Fixes ANTLR-130.

* [...] are allowed in args now but ] must be escaped as \]. E.g.,
  a[String[\] ick, int i] : ... ;
  And calling a rule: foo[x[i\], 34]
  Fixes ANTLR-140.

* Fixed ANTLR-105.  Target.getTargetStringLiteralFromANTLRStringLiteral()
  escaped " that were already escaped.

* target's can now specify how to encode int as char escape.  Moved
  DFA.encodeIntAsCharEscape to Target.

* Bug in runtime.DFA.  If a special state (one with predicate) failed, it
  tried to continue (causing out of range exception due to state = -1)
  instead of reporting error.

* If -dfa with combined grammar T.g, builds T.dec-*.dot and TLexer.dec-*.dot

* Fix ANTLR-165.
  Generate TParser.java and TLexer.java from T.g if combined, else
  use T.java as output regardless of type.
  BACKWARD INCOMPATIBILITY since file names change.
  I changed the examples-v3/java to be consistent.  Required XML.g ->
  XMLLexer.java and fuzzy/Main.java change.

* Fix ANTLR-169.  Deletes tmp lexer grammar file.

December 25, 2007

* Fixed ANTLR-111.  More unit tests in TestAttributes.

December 25, 2007

* Dangling states ("decision cannot distinguish between alternatives
  for at least one input sequence") is now an error not a warning.

* Added sample input sequence that leads to dangling DFA state, one
  that cannot reach an accept state.  ANTLR ran into a case where
  the same input sequence reaches multiple locations in the NFA
  (and so not nondeterministic), but analysis ran out of further
  NFA states to look for more input.  Commonly at EOF target states.
  Now says:

  error(202): CS.g:248:95: the decision cannot distinguish between alternative(s) 1,2 for input such as "DOT IDENTIFIER EOF"

  Also fixed bug where dangling states did not resolve to stop states.

* Fixed ANTLR-123

December 17-21, 2007

* k=1 doesn't prevent backtracking anymore as in
  (options {k=1;}:'else' statement)?
  if backtrack=true for overall grammar.  Set to false in subrule.

* Optimized the analysis engine for LL(1).  Doesn't attempt LL(*) unless
  LL(1) fails.  If not LL(1) but autobacktracking but no other kind of
  predicate, it also avoids LL(*).  This is only important for really
  big 4000 line grammars etc...

* Lots of code clean up

December 16, 2007

* Yet more Kay pair programming.  Saved yet more RAM; 15% by
  wacking NFA configurations etc in each DFA state after DFA construction.

* Overall we drop from 2m49s to 1m11s for a huge 4000 line TSQL grammar
  with k=*.  Only needs -Xconversiontimeout 2000 now not
  -Xconversiontimeout 5000 too.  With k=1, it's 1m30s down to 40s.

December 15, 2007

* Working with Kay Roepke, we got about 15% speed improvement in
  overall ANTLR exec time.  Memory footprint seems to be about 50%
  smaller.

December 13-14, 2007

* I abort entire DFA construction now when I see recursion in > 1 alt.
  Decision is non-LL(*) even if some pieces are LL(*).  Safer to bail
  out and try with fixed k.  If user set fixed k then it continues because
  analysis will eventually terminate for sure.  If a pred is encountered
  and k=* and it's non-LL(*), it aborts and retries at k=1 but does NOT
  emit an error.

* Decided that recursion overflow while computing a lookahead DFA is
  serious enough that I should bail out of entire DFA computation.
  Previously analysis tried to keep going and made the rules about
  how analysis worked more complicated.  Better to simply abort when
  decision can't be computed with current max stack (-Xm option).
  User can adjust or add predicate etc...  This is now an error
  not a warning.

* Recursion overflow and unreachable alt is now a fatal error; no code gen.
  The decision will literally not work.

* Cleaned up how DFA construction/analysis aborts due to non-LL(*) and
  overflow etc...  Throws exceptions now, which cleans up a bunch of IF
  checks etc...  Very nice now. Exceptions:
	analysis/AnalysisRecursionOverflowException.java
	analysis/AnalysisTimeoutException.java
	analysis/NonLLStarDecisionException.java

* ErrorManager.grammarWarning() counted them as errors not warnings.

* Unreachable alt warnings are now errors.

* The upshot of these changes is that I fixed ANTLR-178 and did
  lots of refactoring of code handling analysis failure.

December 11, 2007

* Could not deal with spaces, oddly enough in arg lists:
	grammar Bad;
	a : A b["foo", $A.text] ;
	b[String x, String y] : C ;

October 28, 2007

* Made ANTLR emit a better error message when it cannot write the
  implicit lexer file from a combined grammar. Used to say "cannot open
  file", now says "cannot write file" and gives backtrace.

September 15, 2007

add getCharStream to Lexer.

September 10, 2007

* Added {{...}} forced action executed even during backtracking.

September 9, 2007

* r='string' in lexer got a duplicate label definition.

August 21, 2007

* $scope::variable refs now check for empty stack so that expr == null if
  $scope has an empty stack. Works for $scope[...]::variable too.  Nice!

August 20, 2007

* Added reset() to CommonTreeNodeStream, token stream too

* Made refs to rule/token properties use ?: to avoid null ptr exception.
  $label.st now is label!=null?label.st:null.  Updated TestAttributes.
  This is useful not only for optional rule/token refs, but also during
  error recovery.  If ID is not matched, $ID.text won't cause a null ptr.

August 20, 2007
*	Fixed ANTLR-177: hashCode/equals not consistent for label
	Fixed bug where Rule was compared to string; introduced from dev branch

August 15, 2007 -- Got rough draft of the grammar import working.
                   Submit to dev and then integrate into mainline.

	All file changes/additions:

	README.txt	# edit
	CHANGES.txt	# add
	  Factored out the changes from the readme.

	runtime/Java/src/org/antlr/runtime/BaseRecognizer.java	# edit
	runtime/Java/src/org/antlr/runtime/DFA.java	# edit
	runtime/Java/src/org/antlr/runtime/Lexer.java	# edit
	runtime/Java/src/org/antlr/runtime/Parser.java	# edit
	runtime/Java/src/org/antlr/runtime/debug/DebugParser.java	# edit
	runtime/Java/src/org/antlr/runtime/tree/TreeParser.java	# edit
	  Factored state fields into RecognizerSharedState
	  object. You will see a lot of things like
            state.errorRecovery = false;
	runtime/Java/src/org/antlr/runtime/RecognizerSharedState.java	# add
          Shares all recognizer state variables including lexer even though
	  these are superfluous to parsers and tree parsers.  There
	  was a casting issue that I could not resolve.

	src/org/antlr/Tool.java	# edit
	  Broke a part Grammar.setGrammarContent() into
	  parseAndBuildAST() and analyzeGrammar() to make the grammar
	  import work. I needed to be able to look at the trees for
	  imported grammars before analyzing them and building DFA. Added
	  use of the CompositeGrammar object and handling of multiple
	  delegate grammars. Changed decision DFA DOT file names to
	  include the grammar name.

	src/org/antlr/analysis/DFA.java	# edit
	  Just tweaked to use generics, updated a comment.

	src/org/antlr/analysis/DecisionProbe.java	# edit
	  Just tweaked to use generics.

	src/org/antlr/analysis/NFA.java	# edit
	  NFA now span multiple grammars and so I moved the NFAs state
	  tracking to the composite grammar object.

	src/org/antlr/analysis/NFAState.java	# edit
	  Added some null checking and made a field public.

	src/org/antlr/analysis/NFAToDFAConverter.java	# edit
	  Changed a method call to directly access a field.

	src/org/antlr/analysis/RuleClosureTransition.java	# edit
	  Instead of using a rule index, which does not span multiple
	  grammars, the transition object now attracts a pointer to
	  the actual Rule definition object.

	src/org/antlr/analysis/SemanticContext.java	# edit
	  Tweaked to use a field instead of a method

	src/org/antlr/codegen/ActionTranslator.g	# edit
	src/org/antlr/codegen/ActionTranslatorLexer.java	# edit
	  Tweaked to use new runtime and they changed method name.

	src/org/antlr/codegen/CodeGenerator.java	# edit
	  Tweaked comments.

	src/org/antlr/codegen/codegen.g	# edit
	  Added import grammar syntax and altered rule atom to pass a
	  scope around so that grammar.rule works.  Caution this
	  feature is used internally by ANTLR and is not meant to be
	  used by users at this point.

	src/org/antlr/codegen/templates/ANTLRCore.sti	# edit
	  Added scope to all ruleref template interfaces.

	src/org/antlr/codegen/templates/Java/Java.stg	# edit
	  Grammars can now import other grammars, which I implemented
	  using a delegation pointer to the other grammar(s). So if
	  grammar A imports grammars B and C, then the generated
	  recognizer for A must have delegation pointers to BParser
	  and CParser objects. These are now fields:

	    // delegates
	    <grammar.delegates:
	     {g|public <g.name>Lexer <g:delegateName()>;}; separator="\n">

          Also, B and C must have back pointers to the delegator so
          that they can refer to rules that have been overridden.
          This is a mechanism akin to static inheritance:

	    // delegators
	    <grammar.delegators:
	     {g|public <g.name>Lexer <g:delegateName()>;}; separator="\n">

	  This file also has a lot of changes so that state variables
	  now are state.backtracking instead of the implied
	  this.backtracking.

	  The file also refers to grammar.delegatedRules attribute
	  which is the list of Rule objects for which you must
	  generate manual delegation.  This amounts to a stub whereby
	  rule foo's method foo() simply calls X.foo() if foo is not
	  defined inside the delegator.

	  You will notice that the ruleref templates now take a scope
	  so that I can have implicit rule Tokens referred to
	  delegate.Tokens rule in a delegate grammar.  This is the way
	  I do lexer grammar imports.

	  I added a template called delegateName which uses the
	  grammar name to compute a delegate name if the user does not
	  specify a label in the import statement such as:

	  import x=X;

	  Oh, note that rule reference templates all receive a Rule
	  object now instead of the simple rule name as the 'rule'
	  attribute.  You will see me doing <rule.name> instead of
	  <name> now.

	src/org/antlr/codegen/templates/Java/Dbg.stg	# edit
	  Changes mirroring the constructor and field stuff from
	  Java.stg. Part of this is a cut and paste because of a bug
	  in ST.

	src/org/antlr/codegen/templates/Java/AST.stg	# edit
	src/org/antlr/codegen/templates/Java/ASTParser.stg	# edit
	src/org/antlr/codegen/templates/Java/ASTTreeParser.stg	# edit
	  Just added the scope attribute.

	src/org/antlr/test/BaseTest.java	# edit
	  Added functionality to support testing composite grammars.
	    execLexer()

	src/org/antlr/test/TestAttributes.java	# edit
	  Tweak to deal with shared recognizer state.

	src/org/antlr/test/TestCompositeGrammars.java	# add
	  Start of my unit tests.

	src/org/antlr/tool/CompositeGrammar.java	# add
	src/org/antlr/tool/CompositeGrammarTree.java	# add
	  Tracks main grammar and all delegate grammars. Tracks unique
	  NFA state numbers and unique token types. This keeps a tree
	  of grammars computed from the import/delegation chain. When
	  you want to look up a rule, it starts at the root of the
	  tree and does a pre-order search to find the rule.

	src/org/antlr/tool/ActionAnalysis.g	# edit
	src/org/antlr/tool/ActionAnalysisLexer.java	# edit

	src/org/antlr/tool/AttributeScope.java	# edit
	  Updated to use generics in one place.

	src/org/antlr/tool/DOTGenerator.java	# edit
	  Updated to indicate when nonlocal rules are referenced.

	src/org/antlr/tool/ErrorManager.java	# edit
	  Added some error messages for import grammars; I need more.

	src/org/antlr/tool/FASerializer.java	# edit
	  Tweaked to use a field not method.

	src/org/antlr/tool/Grammar.java	# edit
	  This is where most of the meat is for the grammar import
	  stuff as you can imagine.  I factored out the token type
	  tracking into the CompositeGrammar object. I added code to
	  the addArtificialMatchTokensRule method so that it includes
	  references to all delegate lexer Tokens rules. Altered the
	  rule lookup stuff so that it knows about delegate grammars.

	src/org/antlr/tool/GrammarAST.java	# edit
	src/org/antlr/tool/GrammarAnalysisAbortedMessage.java	# edit
	src/org/antlr/tool/GrammarReport.java	# edit
	src/org/antlr/tool/NonRegularDecisionMessage.java	# edit
	  Made enclosing rule visible as field.

	src/org/antlr/tool/GrammarSanity.java	# edit
	  General cleanup and addition of generics.

	src/org/antlr/tool/Interpreter.java	# edit
	  Reference fields instead of methods.

	src/org/antlr/tool/NFAFactory.java	# edit
	  General cleanup and use of Rule object instead of rule
	  index.

	src/org/antlr/tool/NameSpaceChecker.java	# edit
	  A little bit of cleanup and changes to use either the local
	  or globally visible rule. Added code to check that scopes
	  are valid on scoped rule references. again this is an
	  internal feature, not to be used by users.

	src/org/antlr/tool/RandomPhrase.java	# edit
	  Tweaked.

	src/org/antlr/tool/Rule.java	# edit
	  Added field imported. Removed some unused methods by
	  commenting them out. Made toString() more expressive.

	src/org/antlr/tool/antlr.g	# edit
	src/org/antlr/tool/antlr.print.g	# edit
	src/org/antlr/tool/assign.types.g	# edit
	src/org/antlr/tool/buildnfa.g	# edit
	src/org/antlr/tool/define.g	# edit
	  Added syntax for import statement.  assign.types.g is the
	  grammar that invokes Grammar.importGrammar().

	src/org/antlr/tool/templates/messages/languages/en.stg	# edit
	  Added error messages.

	Added

	CHANGES.txt
	runtime/Java/src/org/antlr/runtime/RecognizerSharedState.java
	src/org/antlr/test/TestCompositeGrammars.java
	src/org/antlr/tool/CompositeGrammar.java
	src/org/antlr/tool/CompositeGrammarTree.java

3.0.1 - August 13, 2007

[See target pages on the wiki for more information on the non-Java targets]

August 7, 2007

* added escaping of double quotes in DOTTreeGenerator

July 22, 2007

* fixed dynamic scope implementation in lexers. They were not creating new scope
  entries on the stack.  Unsupported feature!

July 30, 2007

* float return values were initalized to 0.0 not 0.0f in java.

July 28, 2007

* Sam Ellis points out an init var bug in ANTLRReaderStream.

July 27, 2007 (done in dev branch)

* Moved token type index stuff from CommonTreeNodeStream to TreeWizard

* Added getChildren to BaseTree.

* Added heterogeneous tree functionality; rewrite for parser/tree parser
  and auto AST constr. for parser.

	org/antlr/runtime/tree/RewriteRuleElementStream.java
	org/antlr/runtime/tree/RewriteRuleNodeStream.java
	org/antlr/runtime/tree/RewriteRuleTokenStream.java
		Renamed method next() and re-factor things to have more
		specific methods: nextToken, nextNode, nextTree.

	codegen/codegen.g
		Updated to include new <NodeType> AST structure for
		token references.  Pushed hereto attribute into
		all tokenRef* templates.
	codegen/templates/Java/AST.stg
		Factored out a few templates:
			createImaginaryNode(tokenType,hetero,args)
			createRewriteNodeFromElement(token,hetero,args)
		Converted a lot of stream next() calls to more specific
			nextToken, nextNode, nextTree per above.
	codegen/templates/Java/ASTParser.stg
		Added createNodeFromToken template and re-factored creation
		sites to use that template.  Added hetero attribute.
	codegen/templates/Java/ASTTreeParser.stg
		Added createRewriteNodeFromElement template and re-factored.

	test/TestHeteroAST.java
		New file. Unit tests to test new hetero tree construction.
	test/TestRewriteAST.java
		Fixed test.  Nil single-node trees no longer return nil;
		They return null.

	tool/ErrorManager.java
	tool/templates/messages/languages/en.stg
		Added error message:
		HETERO_ILLEGAL_IN_REWRITE_ALT(arg) ::=
		  "alts with rewrites can't use heterogeneous types left of ->"

	tool/antlr.g
	tool/antlr.print.g
	tool/assign.types.g
	tool/buildnfa.g
	tool/define.g
		Added syntax for <NodeType> to token references.
		Altered AST structure rippled through different phases.

July 24, 2007

* Deleted DoubleLinkTree.java; CommonTree does that now.

July 23, 2007

* template group outputFile; changed rewrite arg to rewriteMode.

* added rewrite mode for tree parser build AST.

July 22, 2007

* Kay fixed dynamic scope implementation in lexers. They were not
  creating new scope entries on the stack.  This is an UNSUPPORTED feature.

* added getParent and getChildIndex to TreeAdaptor.  Added
  implementation to CommonTree.  It's just too useful having those
  parent and child indexes available for rewriting etc...  I tried 2x
  to make an implementation of tree rewriting w/o this and the
  constraints just made it too expensive and complicated.  Have to
  update adaptors to set parent, child index values.  Updated Tree
  interface and BaseTree also.  Should only affect target developers
  not users.  Well, unless they impl Tree.

* dupNode (via ctor) of CommonTree didn't copy start/stop token indexes.

TARGET DEVELOPERS WARNING -- AST.stg split with some functionality
                             going into ASTParser.stg then I added
                             ASTTreeParser.stg.  CodeGenerator
                             assumes new subgroups exist.

July 20, 2007

* Added AST construction for tree parsers including -> rewrite rules.
  Rewrite mode (rewrite=true) alters the tree in place rather than
  constructing a whole new tree.  Implementation notes:

  org/antlr/runtime/tree/Tree.java
	Add methods for parent and child index functionality.
	Also added freshenParentAndChildIndexes() which you can use
	to ensure that all double linking is set up right after you
	manipulate the tree manually.  The setChild preteens etc. do
	the proper thing so you shouldn't need this.
	Added replaceChildren() to support tree rewrite mode in tree parsers
  org/antlr/runtime/tree/BaseTree.java
	Updated to set parent and child index stuff.  Added replaceChildren
	method etc...  It still only has a list of children as sole field
     	but calls methods that subclasses can choose to implement such as
	CommonTree.
  org/antlr/runtime/tree/CommonTree.java
	Added parent and childIndex fields to doubly link.
  org/antlr/runtime/tree/TreeAdaptor.java
	Added methods for new parent and child index functionality.
	Also added method for rewrite mode in tree parsers:
	replaceChildren(Object parent, int startChildIndex,
                        int stopChildIndex, Object t);
	Added setChild and deleteChild methods
  org/antlr/runtime/tree/BaseTreeAdaptor.java
	Moved dupTree here from BaseTree.
	Updated rulePostProcessing to deal with parent and child index.
	Added setChild and deleteChild implementations
  org/antlr/runtime/tree/CommonTreeAdaptor.java
	Added methods to deal with the parent and child index for a node.

  org/antlr/runtime/tree/CommonTreeNodeStream.java
	Removed token type index and method fillReverseIndex etc...
	Probably will move into the tree wizard in the future.
	Changed call/seek stack implementation to use IntArray
	Added replaceChildren interface.
  org/antlr/runtime/tree/TreeNodeStream.java
	Added replaceChildren.
  org/antlr/runtime/tree/UnBufferedTreeNodeStream.java
	Added replaceChildren method but no implementation

  codegen/templates/ANTLRCore.sti
	Changed rewrite to a better name: rewriteMode
	Added tree level argument to alt, tree so that auto AST
        construction can occur while recognizing in tree parsers.

  codegen/templates/Java/AST.stg
	Split template group: added two subclasses to handle different
	functionality for normal parsing and tree parsing + AST
	construction.  Tree parsers default behavior is to dup tree
	not construct another.  Added ASTParser.stg and
	ASTTreeParser.stg to handle auto AST construction during
	recognition for the two different parser types.  I just copied
	the token, rule, set, wildcard templates to the subclasses.
	The rewrite templates are still in AST.stg. I factored out the
	node creation so that the same rewrite templates can be used
	for both parsing and tree parsing.

  codegen/templates/Java/ASTParser.stg
	The templates needed to build trees with auto construction
	during parsing.
  codegen/templates/Java/ASTTreeParser.stg
	The templates needed to build trees with auto construction
	during tree parsing.
  codegen/templates/Java/Java.stg
	genericParser now has rewriteElementType (Note or Token) so
	that the rewrite streams know what kind of elements are inside
	during rewrite rule tree construction.
  codegen/templates/Java/ST.stg
	rewrite attribute name change to rewriteMode

  org/antlr/runtime/debug/DebugTreeAdaptor.java
  org/antlr/runtime/debug/DebugTreeNodeStream.java
	Updated to handle new interfaces

  test/BaseTest.java
	Added test rig update to handle AST construction by tree parsers.
	All tree construction runs automatically test sanity of parent
	and child indexes.
  test/TestTreeGrammarRewriteAST.java
  test/TestTreeNodeStream.java
  test/TestTrees.java
	new file; tests the new parent and child index stuff in trees.

July 19, 2007

* implemented new unique ID; GC was causing non unique hash codes.  Debugging
  tree grammars was messing up.

* got tree rewrites working in tree grammars.  It builds a completely new
  tree from old tree; i.e., you get two trees in memory.  W/o a rewrite
  rule, the input for that rule is duplicated and returned. -> w/o elements
  to the right means don't return anything; i.e., delete.  Ooops...way
  harder than I thought.  Real implementation notes above.

INCOMPATIBILITY WARNING -- templates have changed; must regen output from
                           grammars.  Runtime libraries have also changed.
                           Debug event listener interface has changed also.

July 17, 2007

* Added line/charposition to node socket events and event dump so
  we have more info during tree parsing.  Only works if your
  tree adaptor returns a value Token object from getToken(treenode)
  with line/col set.  Refactored consumeNode/LN to use deserializeNode().

* Fixed mismatched tree node exceptions; for imaginary nodes, it said
  "missing null".  Now prints the token type we found.

* Cleaned up exception stuff. MismatchedTreeNodeException was setting
  line/col, but only RecognitionException should do that.

* If imaginary token gets a mismatch, there is no line info.  Search
  backwards in stream if input node stream supports to find last
  node with good line/col info. E.g.,

ANTLRv3Tree.g: node from after line 156:72 mismatched tree node: EOA expecting <UP>

  which used to be:

ANTLRv3Tree.g: node from line 0:0 mismatched tree node: null expecting <UP>

* mismatched tree node exceptions were not sent to the debug event stream.
  Due to a type being slightly different on recoverFromMismatchedToken()
  in DebugTreeParser.  Was calling BaseRecognizer version not subclass.
  Now we get:

  9459:   Recognition exception MismatchedTreeNodeException(0!=0)

* List labels were not allowed as root nodes in tree rewrites like
  ^($listlabel ...).  Had to add a template to AST.stg:

  /** Gen ^($label ...) where label+=... */
  rewriteTokenListLabelRefRoot ::= rewriteTokenLabelRefRoot


July 16, 2007

* fixed nextNode in RewriteRuleSubtreeStream was dup'ing too much,
  screwing up debug event stream.  Also there was a bug in how
  the rewrite tree stream stuff decided to dup nodes.

* fixed bug in LT for tree parsing; text was not transmitted properly;
  only single words worked.

* made decision for rule put line/col on colon not first token of first alt.

* remote ProxyToken now emits token index for easier debugging when looking
  at AW's event stream.  For example, the @5 here is the token index:

  31	Consume hidden [ /<64>,channel=99,30:7, @5]

* same is true for consume nodes now:

  25586	Consume node [')'/, <44>, 4712040,@1749]	25

  When debugging tree parsers, it helps to track errors when you know
  what corresponding input symbol created this tree node.

* Changed debug events associated with trees quite a bit.  Passes nodes around
  now rather than text, type, unique IDs etc...  Mostly affects internal stuff.
  Target developers will have some work in their runtime to do to match
  this change. :(  BUT, there is only a slight tweak in the Dbg.stg
  and ASTDbg.stg templates.
  Interface just didn't make sense as is.  If you turn on debugging, and
  want to track a node creation, you want the node pointer not its ID,
  text, etc...
  Added ProxyTree for passing across socket.  Has line/charpos and tokenIndex

July 15, 2007

* added null ptr protection in CommonTreeAdaptor.

July 14, 2007

* null child in TreeAdaptor does nothing now.  Changed interface and
  implementation.  Changed DebugTreeAdaptor to not fire events on null add
  as well.

July 12, 2007

* added get method for the line/col to DFA map in Grammar.java

July 7, 2007

* fixed wrong order of test for exceptions in Lexer.getErrorMessage()

June 28, 2007

* Added ability to set the port number in the constructor for the debug parser.

June 5, 2007

* Changed (hidden) option -verbose to -Xnfastates; this just prints out the NFA states along each nondeterministic path for nondeterminism warnings.

May 18, 2007

* there were some dependencies with org.antlr.* that I removed from
  org.antlr.runtime.*

3.0 final - May 17, 2007

May 14, 2007

* Auto backtracking didn't work with ! and ^ suffixes on first element
  of an alt.

* Auto backtracking didn't work with an action as first element.

May 10, 2007

* turn off the warning about no local messages:
 no such locale file org/antlr/tool/templates/messages/languages/ru.stg retrying with English locale

May 5, 2007

* moving org.antlr.runtime to runtime/Java/src/org/... Other target
  source / libs are under runtime/targetname.

May 4, 2007

* You could not use arguments on a token reference that was a route in a
  tree rewrite rule like -> ^(ID[args] ...).

May 3, 2007

* Fixed ANTLR-82.  Actions after the root were considered part of
  an optional child.  They were not always executed.  Required a change
  to the ANTLRCore.sti interface for tree() template.

May 2, 2007

* Fixed ANTLR-117. Wasn't building decisions properly for subrules in
  syntactic predicates.

April 22, 2007

* Made build.xml ref all jars in antlr lib.  Thanks to Miguel Ping.

* Fixed ANTLR-11

* Now labels on ranges and such in lexer work properly.

* ActionAnalysisLexer was in wrong package.

April 21, 2007

* Pushing a huge update that fixes:
	http://www.antlr.org/browse/ANTLR-112
	http://www.antlr.org/browse/ANTLR-110
	http://www.antlr.org/browse/ANTLR-109
	http://www.antlr.org/browse/ANTLR-103
	http://www.antlr.org/browse/ANTLR-97
	http://www.antlr.org/browse/ANTLR-113
	http://www.antlr.org/browse/ANTLR-66
	http://www.antlr.org/browse/ANTLR-98
	http://www.antlr.org/browse/ANTLR-24
	http://www.antlr.org/browse/ANTLR-114
	http://www.antlr.org/browse/ANTLR-5
	http://www.antlr.org/browse/ANTLR-6

  Basically, I gutted the way AST rewrites work.  MUCH better.

* Fixed lots of little label issues in the lexer.  Couldn't do x+=ID
  in lexer, for example.  Fixed ANTLR-114, ANTLR-112

* Isolated EOT transition in lexer generated dangling else clause.
  Fixed ANTLR-113.

April 17, 2007

* Fixed a major problem with gated semantic predicates.  Added more
  unit tests.

* Fixed bug in cyclic DFA with syntactic predicates.  Wasn't rewinding
  properly.  Further, mark() in token stream did not fill buffer so
  when you rewound back to last marker index was -1 not 0.  At same time
  I fixed ANTLR-103.  Syn preds evaluated only once now.

* Altered code gen file writing so it writes directly to a file
  instead of building a big string and then writing that out.  Should
  be faster and much less memory intensive.

* Fixed so antlr writes files to correct location again.  See:

http://www.antlr.org/wiki/pages/viewpage.action?pageId=1862

3.0b7 - April 12, 2007

April 10, 2007

* Allows -> {...} actions now when building ASTs.  Fixed ANTLR-14.

* Allows ! on sets and wildcard now during output=AST option. Fixed ANTLR-17.

* Fixed ANTLR-92 bug.  Couldn't use sets with -> tree construction.

* No lexer rule for a token type is now a warning.

* Fixed set labels in lexer; ANTLR-60 bug

* Fixed problem with duplicate state variable definitions in switch-case

April 9, 2007

* Gated predicates didn't work properly in cyclic DFA.

April 7, 2007

* Couldn't have more than one set per rule it seems.  Fixed.

April 3, 2007

* Fix a problem in my unused label optimization.  Added new
  pass over actions to examine them.

* RuleReturnScope has method back:
  /** Has a value potentially if output=template; Don't use StringTemplate
   *  type as it then causes a dependency with ST lib.
   */
  public Object getTemplate() { return null; }

March 30, 2007

* Fixed ANTLR-8.  Labels to rules w/o return values caused compile errors.

* Fixed ANTLR-89; semantic predicates in lexer sometimes
  caused exception in code gen.

* Fixed ANTLR-36; remove runtime dependency with ST

March 29, 2007

* Over last few days, I've gutted how ANTLR handles sets of chars or
  tokens.  I cleaned up a lot of stuff in the grammars and added lots
  of unit tests.

March 26, 2007

* CommonTreeNodeStream didn't push correctly; couldn't handle very
  deeply nested trees.

* Fixed bug that E : 'a' 'b' ; made E be seen as an alias of 'a'.

March 22, 2007

* Working with Egor Ushakov from Sun Optimization / NetBeans team I
  made all the Java lexer transition tables static w/o screwing up
  ability to reference semantic predicates etc...  Only changed Java.stg

* cached text string in CommonToken.getText(); saves on repeated calls;
  Java mode.

* made all generated methods final; saves a few percent speed according to
  Egor Ushakov (Java only).

* removed most assignments from each lexer rule and even the Lexer.emit()
  call!  All done in nextToken now.  Saves on code gen size and a wee bit of
  execution speed probably.  Variables became fields: type, channel, line,
  etc... Now emit() needs no args even.  Again, Egor helped on this.

March 17, 2007

* Jonathan DeKlotz updated C# templates to be 3.0b6 current

March 14, 2007

* Manually-specified (...)=> force backtracking eval of that predicate.
  backtracking=true mode does not however.  Added unit test.

March 14, 2007

* Fixed bug in lexer where ~T didn't compute the set from rule T.

* Added -Xnoinlinedfa make all DFA with tables; no inline prediction with IFs

* Fixed http://www.antlr.org/browse/ANTLR-80.
  Sem pred states didn't define lookahead vars.

* Fixed http://www.antlr.org/browse/ANTLR-91.
  When forcing some acyclic DFA to be state tables, they broke.
  Forcing all DFA to be state tables should give same results.

March 12, 2007

* setTokenSource in CommonTokenStream didn't clear tokens list.
  setCharStream calls reset in Lexer.

* Altered -depend.  No longer printing grammar files for multiple input
  files with -depend.  Doesn't show T__.g temp file anymore. Added
  TLexer.tokens.  Added .h files if defined.

February 11, 2007

* Added -depend command-line option that, instead of processing files,
  it shows you what files the input grammar(s) depend on and what files
  they generate. For combined grammar T.g:

  $ java org.antlr.Tool -depend T.g

  You get:

  TParser.java : T.g
  T.tokens : T.g
  T__.g : T.g

  Now, assuming U.g is a tree grammar ref'd T's tokens:

  $ java org.antlr.Tool -depend T.g U.g

  TParser.java : T.g
  T.tokens : T.g
  T__.g : T.g
  U.g: T.tokens
  U.java : U.g
  U.tokens : U.g

  Handles spaces by escaping them.  Pays attention to -o, -fo and -lib.
  Dir 'x y' is a valid dir in current dir.

  $ java org.antlr.Tool -depend -lib /usr/local/lib -o 'x y' T.g U.g
  x\ y/TParser.java : T.g
  x\ y/T.tokens : T.g
  x\ y/T__.g : T.g
  U.g: /usr/local/lib/T.tokens
  x\ y/U.java : U.g
  x\ y/U.tokens : U.g

  You have API access via org.antlr.tool.BuildDependencyGenerator class:
  getGeneratedFileList(), getDependenciesFileList().  You can also access
  the output template: getDependencies().  The file
  org/antlr/tool/templates/depend.stg contains the template.  You can
  modify as you want.  File objects go in so you can play with path etc...

February 10, 2007

* no more .gl files generated.  All .g all the time.

* changed @finally to be @after and added a finally clause to the
  exception stuff.  I also removed the superfluous "exception"
  keyword.  Here's what the new syntax looks like:

  a
  @after { System.out.println("ick"); }
    : 'a'
    ;
    catch[RecognitionException e] { System.out.println("foo"); }
    catch[IOException e] { System.out.println("io"); }
    finally { System.out.println("foobar"); }

  @after executes after bookkeeping to set $rule.stop, $rule.tree but
  before scopes pop and any memoization happens.  Dynamic scopes and
  memoization are still in generated finally block because they must
  exec even if error in rule.  The @after action and tree setting
  stuff can technically be skipped upon syntax error in rule.  [Later
  we might add something to finally to stick an ERROR token in the
  tree and set the return value.]  Sequence goes: set $stop, $tree (if
  any), @after (if any), pop scopes (if any), memoize (if needed),
  grammar finally clause.  Last 3 are in generated code's finally
  clause.

3.0b6 - January 31, 2007

January 30, 2007

* Fixed bug in IntervalSet.and: it returned the same empty set all the time
  rather than new empty set.  Code altered the same empty set.

* Made analysis terminate faster upon a decision that takes too long;
  it seemed to keep doing work for a while.  Refactored some names
  and updated comments.  Also made it terminate when it realizes it's
  non-LL(*) due to recursion.  just added terminate conditions to loop
  in convert().

* Sometimes fatal non-LL(*) messages didn't appear; instead you got
  "antlr couldn't analyze", which is actually untrue.  I had the
  order of some prints wrong in the DecisionProbe.

* The code generator incorrectly detected when it could use a fixed,
  acyclic inline DFA (i.e., using an IF).  Upon non-LL(*) decisions
  with predicates, analysis made cyclic DFA.  But this stops
  the computation detecting whether they are cyclic.  I just added
  a protection in front of the acyclic DFA generator to avoid if
  non-LL(*).  Updated comments.

January 23, 2007

* Made tree node streams use adaptor to create navigation nodes.
  Thanks to Emond Papegaaij.

January 22, 2007

* Added lexer rule properties: start, stop

January 1, 2007

* analysis failsafe is back on; if a decision takes too long, it bails out
  and uses k=1

January 1, 2007

* += labels for rules only work for output option; previously elements
  of list were the return value structs, but are now either the tree or
  StringTemplate return value.  You can label different rules now
  x+=a x+=b.

December 30, 2006

* Allow \" to work correctly in "..." template.

December 28, 2006

* errors that are now warnings: missing AST label type in trees.
  Also "no start rule detected" is warning.

* tree grammars also can do rewrite=true for output=template.
  Only works for alts with single node or tree as alt elements.
  If you are going to use $text in a tree grammar or do rewrite=true
  for templates, you must use in your main:

  nodes.setTokenStream(tokens);

* You get a warning for tree grammars that do rewrite=true and
  output=template and have -> for alts that are not simple nodes
  or simple trees.  new unit tests in TestRewriteTemplates at end.

December 27, 2006

* Error message appears when you use -> in tree grammar with
  output=template and rewrite=true for alt that is not simple
  node or tree ref.

* no more $stop attribute for tree parsers; meaningless/useless.
  Removed from TreeRuleReturnScope also.

* rule text attribute in tree parser must pull from token buffer.
  Makes no sense otherwise.  added getTokenStream to TreeNodeStream
  so rule $text attr works.  CommonTreeNodeStream etc... now let
  you set the token stream so you can access later from tree parser.
  $text is not well-defined for rules like

     slist : stat+ ;

  because stat is not a single node nor rooted with a single node.
  $slist.text will get only first stat.  I need to add a warning about
  this...

* Fixed http://www.antlr.org/browse/ANTLR-76 for Java.
  Enhanced TokenRewriteStream so it accepts any object; converts
  to string at last second.  Allows you to rewrite with StringTemplate
  templates now :)

* added rewrite option that makes -> template rewrites do replace ops for
  TokenRewriteStream input stream.  In output=template and rewrite=true mode
  same as before 'cept that the parser does

    ((TokenRewriteStream)input).replace(
	      ((Token)retval.start).getTokenIndex(),
	      input.LT(-1).getTokenIndex(),
	      retval.st);

  after each rewrite so that the input stream is altered.  Later refs to
  $text will have rewrites.  Here's a sample test program for grammar Rew.

        FileReader groupFileR = new FileReader("Rew.stg");
        StringTemplateGroup templates = new StringTemplateGroup(groupFileR);
        ANTLRInputStream input = new ANTLRInputStream(System.in);
        RewLexer lexer = new RewLexer(input);
        TokenRewriteStream tokens = new TokenRewriteStream(lexer);
        RewParser parser = new RewParser(tokens);
        parser.setTemplateLib(templates);
        parser.program();
        System.out.println(tokens.toString());
        groupFileR.close();

December 26, 2006

* BaseTree.dupTree didn't dup recursively.

December 24, 2006

* Cleaned up some comments and removed field treeNode
  from MismatchedTreeNodeException class.  It is "node" in
  RecognitionException.

* Changed type from Object to BitSet for expecting fields in
  MismatchedSetException and MismatchedNotSetException

* Cleaned up error printing in lexers and the messages that it creates.

* Added this to TreeAdaptor:
	/** Return the token object from which this node was created.
	 *  Currently used only for printing an error message.
	 *  The error display routine in BaseRecognizer needs to
	 *  display where the input the error occurred. If your
	 *  tree of limitation does not store information that can
	 *  lead you to the token, you can create a token filled with
	 *  the appropriate information and pass that back.  See
	 *  BaseRecognizer.getErrorMessage().
	 */
	public Token getToken(Object t);

December 23, 2006

* made BaseRecognizer.displayRecognitionError nonstatic so people can
  override it. Not sure why it was static before.

* Removed state/decision message that comes out of no
  viable alternative exceptions, as that was too much.
  removed the decision number from the early exit exception
  also.  During development, you can simply override
  displayRecognitionError from BaseRecognizer to add the stuff
  back in if you want.

* made output go to an output method you can override: emitErrorMessage()

* general cleanup of the error emitting code in BaseRecognizer.  Lots
  more stuff you can override: getErrorHeader, getTokenErrorDisplay,
  emitErrorMessage, getErrorMessage.

December 22, 2006

* Altered Tree.Parser.matchAny() so that it skips entire trees if
  node has children otherwise skips one node.  Now this works to
  skip entire body of function if single-rooted subtree:
  ^(FUNC name=ID arg=ID .)

* Added "reverse index" from node to stream index.  Override
  fillReverseIndex() in CommonTreeNodeStream if you want to change.
  Use getNodeIndex(node) to find stream index for a specific tree node.
  See getNodeIndex(), reverseIndex(Set tokenTypes),
  reverseIndex(int tokenType), fillReverseIndex().  The indexing
  costs time and memory to fill, but pulling stuff out will be lots
  faster as it can jump from a node ptr straight to a stream index.

* Added TreeNodeStream.get(index) to make it easier for interpreters to
  jump around in tree node stream.

* New CommonTreeNodeStream buffers all nodes in stream for fast jumping
  around.  It now has push/pop methods to invoke other locations in
  the stream for building interpreters.

* Moved CommonTreeNodeStream to UnBufferedTreeNodeStream and removed
  Iterator implementation.  moved toNodesOnlyString() to TestTreeNodeStream

* [BREAKS ANY TREE IMPLEMENTATION]
  made CommonTreeNodeStream work with any tree node type.  TreeAdaptor
  now implements isNil so must add; trivial, but does break back
  compatibility.

December 17, 2006

* Added traceIn/Out methods to recognizers so that you can override them;
  previously they were in-line print statements. The message has also
  been slightly improved.

* Factored BuildParseTree into debug package; cleaned stuff up. Fixed
  unit tests.

December 15, 2006

* [BREAKS ANY TREE IMPLEMENTATION]
  org.antlr.runtime.tree.Tree; needed to add get/set for token start/stop
  index so CommonTreeAdaptor can assume Tree interface not CommonTree
  implementation.  Otherwise, no way to create your own nodes that satisfy
  Tree because CommonTreeAdaptor was doing

	public int getTokenStartIndex(Object t) {
		return ((CommonTree)t).startIndex;
	}

  Added to Tree:

	/**  What is the smallest token index (indexing from 0) for this node
	 *   and its children?
	 */
	int getTokenStartIndex();

	void setTokenStartIndex(int index);

	/**  What is the largest token index (indexing from 0) for this node
	 *   and its children?
	 */
	int getTokenStopIndex();

	void setTokenStopIndex(int index);

December 13, 2006

* Added org.antlr.runtime.tree.DOTTreeGenerator so you can generate DOT
  diagrams easily from trees.

	CharStream input = new ANTLRInputStream(System.in);
	TLexer lex = new TLexer(input);
	CommonTokenStream tokens = new CommonTokenStream(lex);
	TParser parser = new TParser(tokens);
	TParser.e_return r = parser.e();
	Tree t = (Tree)r.tree;
	System.out.println(t.toStringTree());
	DOTTreeGenerator gen = new DOTTreeGenerator();
	StringTemplate st = gen.toDOT(t);
	System.out.println(st);

* Changed the way mark()/rewind() work in CommonTreeNode stream to mirror
  more flexible solution in ANTLRStringStream.  Forgot to set lastMarker
  anyway.  Now you can rewind to non-most-recent marker.

December 12, 2006

* Temp lexer now end in .gl (T__.gl, for example)

* TreeParser suffix no longer generated for tree grammars

* Defined reset for lexer, parser, tree parser; rewinds the input stream also

December 10, 2006

* Made Grammar.abortNFAToDFAConversion() abort in middle of a DFA.

December 9, 2006

* fixed bug in OrderedHashSet.add().  It didn't track elements correctly.

December 6, 2006

* updated build.xml for future Ant compatibility, thanks to Matt Benson.

* various tests in TestRewriteTemplate and TestSyntacticPredicateEvaluation
  were using the old 'channel' vs. new '$channel' notation.
  TestInterpretedParsing didn't pick up an earlier change to CommonToken.
  Reported by Matt Benson.

* fixed platform dependent test failures in TestTemplates, supplied by Matt
  Benson.

November 29, 2006

*  optimized semantic predicate evaluation so that p||!p yields true.

November 22, 2006

* fixed bug that prevented var = $rule.some_retval from working in anything
  but the first alternative of a rule or subrule.

* attribute names containing digits were not allowed, this is now fixed,
  allowing attributes like 'name1' but not '1name1'.

November 19, 2006

* Removed LeftRecursionMessage and apparatus because it seems that I check
  for left recursion upfront before analysis and everything gets specified as
  recursion cycles at this point.

November 16, 2006

* TokenRewriteStream.replace was not passing programName to next method.

November 15, 2006

* updated DOT files for DFA generation to make smaller circles.

* made epsilon edges italics in the NFA diagrams.

3.0b5 - November 15, 2006

The biggest thing is that your grammar file names must match the grammar name
inside (your generated class names will also be different) and we use
$channel=HIDDEN now instead of channel=99 inside lexer actions.
Should be compatible other than that.   Please look at complete list of
changes.

November 14, 2006

* Force token index to be -1 for CommonIndex in case not set.

November 11, 2006

* getUniqueID for TreeAdaptor now uses identityHashCode instead of hashCode.

November 10, 2006

* No grammar nondeterminism warning now when wildcard '.' is final alt.
  Examples:

	a : A | B | . ;

	A : 'a'
	  | .
	  ;

	SL_COMMENT
	    : '//' (options {greedy=false;} : .)* '\r'? '\n'
	    ;

	SL_COMMENT2
	    : '//' (options {greedy=false;} : 'x'|.)* '\r'? '\n'
	    ;


November 8, 2006

* Syntactic predicates did not get hoisting properly upon non-LL(*) decision.  Other hoisting issues fixed.  Cleaned up code.

* Removed failsafe that check to see if I'm spending too much time on a single DFA; I don't think we need it anymore.

November 3, 2006

* $text, $line, etc... were not working in assignments. Fixed and added
  test case.

* $label.text translated to label.getText in lexer even if label was on a char

November 2, 2006

* Added error if you don't specify what the AST type is; actions in tree
  grammar won't work without it.

  $ cat x.g
  tree grammar x;
  a : ID {String s = $ID.text;} ;

  ANTLR Parser Generator   Early Access Version 3.0b5 (??, 2006)  1989-2006
  error: x.g:0:0: (152) tree grammar x has no ASTLabelType option

November 1, 2006

* $text, $line, etc... were not working properly within lexer rule.

October 32, 2006

* Finally actions now execute before dynamic scopes are popped it in the
  rule. Previously was not possible to access the rules scoped variables
  in a finally action.

October 29, 2006

* Altered ActionTranslator to emit errors on setting read-only attributes
  such as $start, $stop, $text in a rule. Also forbid setting any attributes
  in rules/tokens referenced by a label or name.
  Setting dynamic scopes's attributes and your own parameter attributes
  is legal.

October 27, 2006

* Altered how ANTLR figures out what decision is associated with which
  block of grammar.  Makes ANTLRWorks correctly find DFA for a block.

October 26, 2006

* Fixed bug where EOT transitions led to no NFA configs in a DFA state,
  yielding an error in DFA table generation.

* renamed action.g to ActionTranslator.g
  the ActionTranslator class is now called ActionTranslatorLexer, as ANTLR
  generates this classname now. Fixed rest of codebase accordingly.

* added rules recognizing setting of scopes' attributes to ActionTranslator.g
  the Objective C target needed access to the right-hand side of the assignment
  in order to generate correct code

* changed ANTLRCore.sti to reflect the new mandatory templates to support the above
  namely: scopeSetAttributeRef, returnSetAttributeRef and the ruleSetPropertyRef_*
  templates, with the exception of ruleSetPropertyRef_text. we cannot set this attribute

October 19, 2006

* Fixed 2 bugs in DFA conversion that caused exceptions.
  altered functionality of getMinElement so it ignores elements<0.

October 18, 2006

* moved resetStateNumbersToBeContiguous() to after issuing of warnings;
  an internal error in that routine should make more sense as issues
  with decision will appear first.

* fixed cut/paste bug I introduced when fixed EOF in min/max
  bug. Prevented C grammar from working briefly.

October 17, 2006

* Removed a failsafe that seems to be unnecessary that ensure DFA didn't
  get too big.  It was resulting in some failures in code generation that
  led me on quite a strange debugging trip.

October 16, 2006

* Use channel=HIDDEN not channel=99 to put tokens on hidden channel.

October 12, 2006

* ANTLR now has a customizable message format for errors and warnings,
  to make it easier to fulfill requirements by IDEs and such.
  The format to be used can be specified via the '-message-format name'
  command line switch. The default for name is 'antlr', also available
  at the moment is 'gnu'. This is done via StringTemplate, for details
  on the requirements look in org/antlr/tool/templates/messages/formats/

* line numbers for lexers in combined grammars are now reported correctly.

September 29, 2006

* ANTLRReaderStream improperly checked for end of input.

September 28, 2006

* For ANTLRStringStream, LA(-1) was off by one...gave you LA(-2).

3.0b4 - August 24, 2006

* error when no rules in grammar.  doesn't crash now.

* Token is now an interface.

* remove dependence on non runtime classes in runtime package.

* filename and grammar name must be same Foo in Foo.g.  Generates FooParser,
  FooLexer, ...  Combined grammar Foo generates Foo$Lexer.g which generates
  FooLexer.java.  tree grammars generate FooTreeParser.java

August 24, 2006

* added C# target to lib, codegen, templates

August 11, 2006

* added tree arg to navigation methods in treeadaptor

August 07, 2006

* fixed bug related to (a|)+ on end of lexer rules.  crashed instead
  of warning.

* added warning that interpreter doesn't do synpreds yet

* allow different source of classloader:
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if ( cl==null ) {
    cl = this.getClass().getClassLoader();
}


July 26, 2006

* compressed DFA edge tables significantly.  All edge tables are
  unique. The transition table can reuse arrays.  Look like this now:

     public static readonly DFA30_transition0 =
     	new short[] { 46, 46, -1, 46, 46, -1, -1, -1, -1, -1, -1, -1,...};
         public static readonly DFA30_transition1 =
     	new short[] { 21 };
      public static readonly short[][] DFA30_transition = {
     	  DFA30_transition0,
     	  DFA30_transition0,
     	  DFA30_transition1,
     	  ...
      };

* If you defined both a label like EQ and '=', sometimes the '=' was
  used instead of the EQ label.

* made headerFile template have same arg list as outputFile for consistency

* outputFile, lexer, genericParser, parser, treeParser templates
  reference cyclicDFAs attribute which was no longer used after I
  started the new table-based DFA.  I made cyclicDFADescriptors
  argument to outputFile and headerFile (only).  I think this is
  correct as only OO languages will want the DFA in the recognizer.
  At the top level, C and friends can use it.  Changed name to use
  cyclicDFAs again as it's a better name probably.  Removed parameter
  from the lexer, ...  For example, my parser template says this now:

    <cyclicDFAs:cyclicDFA()> <! dump tables for all DFA !>

* made all token ref token types go thru code gen's
  getTokenTypeAsTargetLabel()

* no more computing DFA transition tables for acyclic DFA.

July 25, 2006

* fixed a place where I was adding syn predicates into rewrite stuff.

* turned off invalid token index warning in AW support; had a problem.

* bad location event generated with -debug for synpreds in autobacktrack mode.

July 24, 2006

* changed runtime.DFA so that it treats all chars and token types as
  char (unsigned 16 bit int).  -1 becomes '\uFFFF' then or 65535.

* changed MAX_STATE_TRANSITIONS_FOR_TABLE to be 65534 by default
  now. This means that all states can use a table to do transitions.

* was not making synpreds on (C)* type loops with backtrack=true

* was copying tree stuff and actions into synpreds with backtrack=true

* was making synpreds on even single alt rules / blocks with backtrack=true

3.0b3 - July 21, 2006

* ANTLR fails to analyze complex decisions much less frequently.  It
  turns out that the set of decisions for which ANTLR fails (times
  out) is the same set (so far) of non-LL(*) decisions.  Morever, I'm
  able to detect this situation quickly and report rather than timing
  out. Errors look like:

  java.g:468:23: [fatal] rule concreteDimensions has non-LL(*)
    decision due to recursive rule invocations in alts 1,2.  Resolve
    by left-factoring or using syntactic predicates with fixed k
    lookahead or use backtrack=true option.

  This message only appears when k=*.

* Shortened no viable alt messages to not include decision
  description:

[compilationUnit, declaration]: line 8:8 decision=<<67:1: declaration
: ( ( fieldDeclaration )=> fieldDeclaration | ( methodDeclaration )=>
methodDeclaration | ( constructorDeclaration )=>
constructorDeclaration | ( classDeclaration )=> classDeclaration | (
interfaceDeclaration )=> interfaceDeclaration | ( blockDeclaration )=>
blockDeclaration | emptyDeclaration );>> state 3 (decision=14) no
viable alt; token=[@1,184:187='java',<122>,8:8]

  too long and hard to read.

July 19, 2006

* Code gen bug: states with no emanating edges were ignored by ST.
  Now an empty list is used.

* Added grammar parameter to recognizer templates so they can access
  properties like getName(), ...

July 10, 2006

* Fixed the gated pred merged state bug.  Added unit test.

* added new method to Target: getTokenTypeAsTargetLabel()

July 7, 2006

* I was doing an AND instead of OR in the gated predicate stuff.
  Thanks to Stephen Kou!

* Reduce op for combining predicates was insanely slow sometimes and
  didn't actually work well.  Now it's fast and works.

* There is a bug in merging of DFA stop states related to gated
  preds...turned it off for now.

3.0b2 - July 5, 2006

July 5, 2006

* token emission not properly protected in lexer filter mode.

* EOT, EOT DFA state transition tables should be init'd to -1 (only
  was doing this for compressed tables).  Fixed.

* in trace mode, exit method not shown for memoized rules

* added -Xmaxdfaedges to allow you to increase number of edges allowed
  for a single DFA state before it becomes "special" and can't fit in
  a simple table.

* Bug in tables.  Short are signed so min/max tables for DFA are now
  char[].  Bizarre.

July 3, 2006

* Added a method to reset the tool error state for current thread.
  See ErrorManager.java

* [Got this working properly today] backtrack mode that let's you type
  in any old crap and ANTLR will backtrack if it can't figure out what
  you meant.  No errors are reported by antlr during analysis.  It
  implicitly adds a syn pred in front of every production, using them
  only if static grammar LL(*) analysis fails.  Syn pred code is not
  generated if the pred is not used in a decision.

  This is essentially a rapid prototyping mode.

* Added backtracking report to the -report option

* Added NFA->DFA conversion early termination report to the -report option

* Added grammar level k and backtrack options to -report

* Added a dozen unit tests to test autobacktrack NFA construction.

* If you are using filter mode, you must manually use option
  memoize=true now.

July 2, 2006

* Added k=* option so you can set k=2, for example, on whole grammar,
  but an individual decision can be LL(*).

* memoize option for grammars, rules, blocks.  Remove -nomemo cmd-line option

* but in DOT generator for DFA; fixed.

* runtime.DFA reported errors even when backtracking

July 1, 2006

* Added -X option list to help

* Syn preds were being hoisted into other rules, causing lots of extra
  backtracking.

June 29, 2006

* unnecessary files removed during build.

* Matt Benson updated build.xml

* Detecting use of synpreds in analysis now instead of codegen.  In
  this way, I can avoid analyzing decisions in synpreds for synpreds
  not used in a DFA for a real rule.  This is used to optimize things
  for backtrack option.

* Code gen must add _fragment or whatever to end of pred name in
  template synpredRule to avoid having ANTLR know anything about
  method names.

* Added -IdbgST option to emit ST delimiters at start/stop of all
  templates spit out.

June 28, 2006

* Tweaked message when ANTLR cannot handle analysis.

3.0b1 - June 27, 2006

June 24, 2006

* syn preds no longer generate little static classes; they also don't
  generate a whole bunch of extra crap in the rules built to test syn
  preds.  Removed GrammarFragmentPointer class from runtime.

June 23-24, 2006

* added output option to -report output.

* added profiling info:
  Number of rule invocations in "guessing" mode
  number of rule memoization cache hits
  number of rule memoization cache misses

* made DFA DOT diagrams go left to right not top to bottom

* I try to recursive overflow states now by resolving these states
  with semantic/syntactic predicates if they exist.  The DFA is then
  deterministic rather than simply resolving by choosing first
  nondeterministic alt.  I used to generated errors:

~/tmp $ java org.antlr.Tool -dfa t.g
ANTLR Parser Generator   Early Access Version 3.0b2 (July 5, 2006)  1989-2006
t.g:2:5: Alternative 1: after matching input such as A A A A A decision cannot predict what comes next due to recursion overflow to b from b
t.g:2:5: Alternative 2: after matching input such as A A A A A decision cannot predict what comes next due to recursion overflow to b from b

  Now, I uses predicates if available and emits no warnings.

* made sem preds share accept states.  Previously, multiple preds in a
decision forked new accepts each time for each nondet state.

June 19, 2006

* Need parens around the prediction expressions in templates.

* Referencing $ID.text in an action forced bad code gen in lexer rule ID.

* Fixed a bug in how predicates are collected.  The definition of
  "last predicated alternative" was incorrect in the analysis.  Further,
  gated predicates incorrectly missed a case where an edge should become
  true (a tautology).

* Removed an unnecessary input.consume() reference in the runtime/DFA class.

June 14, 2006

* -> ($rulelabel)? didn't generate proper code for ASTs.

* bug in code gen (did not compile)
a : ID -> ID
  | ID -> ID
  ;
Problem is repeated ref to ID from left side.  Juergen pointed this out.

* use of tokenVocab with missing file yielded exception

* (A|B)=> foo yielded an exception as (A|B) is a set not a block. Fixed.

* Didn't set ID1= and INT1= for this alt:
  | ^(ID INT+ {System.out.print(\"^(\"+$ID+\" \"+$INT+\")\");})

* Fixed so repeated dangling state errors only occur once like:
t.g:4:17: the decision cannot distinguish between alternative(s) 2,1 for at least one input sequence

* tracking of rule elements was on (making list defs at start of
  method) with templates instead of just with ASTs.  Turned off.

* Doesn't crash when you give it a missing file now.

* -report: add output info: how many LL(1) decisions.

June 13, 2006

* ^(ROOT ID?) Didn't work; nor did any other nullable child list such as
  ^(ROOT ID* INT?).  Now, I check to see if child list is nullable using
  Grammar.LOOK() and, if so, I generate an "IF lookahead is DOWN" gate
  around the child list so the whole thing is optional.

* Fixed a bug in LOOK that made it not look through nullable rules.

* Using AST suffixes or -> rewrite syntax now gives an error w/o a grammar
  output option.  Used to crash ;)

* References to EOF ended up with improper -1 refs instead of EOF in output.

* didn't warn of ambig ref to $expr in rewrite; fixed.
list
     :	'[' expr 'for' type ID 'in' expr ']'
	-> comprehension(expr={$expr.st},type={},list={},i={})
	;

June 12, 2006

* EOF works in the parser as a token name.

* Rule b:(A B?)*; didn't display properly in AW due to the way ANTLR
  generated NFA.

* "scope x;" in a rule for unknown x gives no error.  Fixed.  Added unit test.

* Label type for refs to start/stop in tree parser and other parsers were
  not used.  Lots of casting.  Ick. Fixed.

* couldn't refer to $tokenlabel in isolation; but need so we can test if
  something was matched.  Fixed.

* Lots of little bugs fixed in $x.y, %... translation due to new
  action translator.

* Improperly tracking block nesting level; result was that you couldn't
  see $ID in action of rule "a : A+ | ID {Token t = $ID;} | C ;"

* a : ID ID {$ID.text;} ; did not get a warning about ambiguous $ID ref.

* No error was found on $COMMENT.text:

COMMENT
    :   '/*' (options {greedy=false;} : . )* '*/'
        {System.out.println("found method "+$COMMENT.text);}
    ;

  $enclosinglexerrule scope does not exist.  Use text or setText() here.

June 11, 2006

* Single return values are initialized now to default or to your spec.

* cleaned up input stream stuff.  Added ANTLRReaderStream, ANTLRInputStream
  and refactored.  You can specify encodings now on ANTLRFileStream (and
  ANTLRInputStream) now.

* You can set text local var now in a lexer rule and token gets that text.
  start/stop indexes are still set for the token.

* Changed lexer slightly.  Calling a nonfragment rule from a
  nonfragment rule does not set the overall token.

June 10, 2006

* Fixed bug where unnecessary escapes yield char==0 like '\{'.

* Fixed analysis bug.  This grammar didn't report a recursion warning:
x   : y X
    | y Y
    ;
y   : L y R
    | B
    ;
  The DFAState.equals() method was messed up.

* Added @synpredgate {...} action so you can tell ANTLR how to gate actions
  in/out during syntactic predicate evaluation.

* Fuzzy parsing should be more efficient.  It should backtrack over a rule
  and then rewind and do it again "with feeling" to exec actions.  It was
  actually doing it 3x not 2x.

June 9, 2006

* Gutted and rebuilt the action translator for $x.y, $x::y, ...
  Uses ANTLR v3 now for the first time inside v3 source. :)
  ActionTranslator.java

* Fixed a bug where referencing a return value on a rule didn't work
  because later a ref to that rule's predefined properties didn't
  properly force a return value struct to be built.  Added unit test.

June 6, 2006

* New DFA mechanisms.  Cyclic DFA are implemented as state tables,
  encoded via strings as java cannot handle large static arrays :(
  States with edges emanating that have predicates are specially
  treated.  A method is generated to do these states.  The DFA
  simulation routine uses the "special" array to figure out if the
  state is special.  See March 25, 2006 entry for description:
  http://www.antlr.org/blog/antlr3/codegen.tml.  analysis.DFA now has
  all the state tables generated for code gen.  CyclicCodeGenerator.java
  disappeared as it's unneeded code. :)

* Internal general clean up of the DFA.states vs uniqueStates thing.
  Fixed lookahead decisions no longer fill uniqueStates.  Waste of
  time.  Also noted that when adding sem pred edges, I didn't check
  for state reuse.  Fixed.

June 4, 2006

* When resolving ambig DFA states predicates, I did not add the new states
  to the list of unique DFA states.  No observable effect on output except
  that DFA state numbers were not always contiguous for predicated decisions.
  I needed this fix for new DFA tables.

3.0ea10 - June 2, 2006

June 2, 2006

* Improved grammar stats and added syntactic pred tracking.

June 1, 2006

* Due to a type mismatch, the DebugParser.recoverFromMismatchedToken()
  method was not called.  Debug events for mismatched token error
  notification were not sent to ANTLRWorks probably

* Added getBacktrackingLevel() for any recognizer; needed for profiler.

* Only writes profiling data for antlr grammar analysis with -profile set

* Major update and bug fix to (runtime) Profiler.

May 27, 2006

* Added Lexer.skip() to force lexer to ignore current token and look for
  another; no token is created for current rule and is not passed on to
  parser (or other consumer of the lexer).

* Parsers are much faster now.  I removed use of java.util.Stack for pushing
  follow sets and use a hardcoded array stack instead.  Dropped from
  5900ms to 3900ms for parse+lex time parsing entire java 1.4.2 source.  Lex
  time alone was about 1500ms.  Just looking at parse time, we get about 2x
  speed improvement. :)

May 26, 2006

* Fixed NFA construction so it generates NFA for (A*)* such that ANTLRWorks
  can display it properly.

May 25, 2006

* added abort method to Grammar so AW can terminate the conversion if it's
  taking too long.

May 24, 2006

* added method to get left recursive rules from grammar without doing full
  grammar analysis.

* analysis, code gen not attempted if serious error (like
  left-recursion or missing rule definition) occurred while reading
  the grammar in and defining symbols.

* added amazing optimization; reduces analysis time by 90% for java
  grammar; simple IF statement addition!

3.0ea9 - May 20, 2006

* added global k value for grammar to limit lookahead for all decisions unless
overridden in a particular decision.

* added failsafe so that any decision taking longer than 2 seconds to create
the DFA will fall back on k=1.  Use -ImaxtimeforDFA n (in ms) to set the time.

* added an option (turned off for now) to use multiple threads to
perform grammar analysis.  Not much help on a 2-CPU computer as
garbage collection seems to peg the 2nd CPU already. :( Gotta wait for
a 4 CPU box ;)

* switched from #src to // $ANTLR src directive.

* CommonTokenStream.getTokens() looked past end of buffer sometimes. fixed.

* unicode literals didn't really work in DOT output and generated code. fixed.

* fixed the unit test rig so it compiles nicely with Java 1.5

* Added ant build.xml file (reads build.properties file)

* predicates sometimes failed to compile/eval properly due to missing (...)
  in IF expressions.  Forced (..)

* (...)? with only one alt were not optimized.  Was:

        // t.g:4:7: ( B )?
        int alt1=2;
        int LA1_0 = input.LA(1);
        if ( LA1_0==B ) {
            alt1=1;
        }
        else if ( LA1_0==-1 ) {
            alt1=2;
        }
        else {
            NoViableAltException nvae =
                new NoViableAltException("4:7: ( B )?", 1, 0, input);
            throw nvae;
        }

is now:

        // t.g:4:7: ( B )?
        int alt1=2;
        int LA1_0 = input.LA(1);
        if ( LA1_0==B ) {
            alt1=1;
        }

  Smaller, faster and more readable.

* Allow manual init of return values now:
  functionHeader returns [int x=3*4, char (*f)()=null] : ... ;

* Added optimization for DFAs that fixed a codegen bug with rules in lexer:
   EQ			 : '=' ;
   ASSIGNOP		 : '=' | '+=' ;
  EQ is a subset of other rule.  It did not given an error which is
  correct, but generated bad code.

* ANTLR was sending column not char position to ANTLRWorks.

* Bug fix: location 0, 0 emitted for synpreds and empty alts.

* debugging event handshake how sends grammar file name.  Added getGrammarFileName() to recognizers.  Java.stg generates it:

    public String getGrammarFileName() { return "<fileName>"; }

* tree parsers can do arbitrary lookahead now including backtracking.  I
  updated CommonTreeNodeStream.

* added events for debugging tree parsers:

	/** Input for a tree parser is an AST, but we know nothing for sure
	 *  about a node except its type and text (obtained from the adaptor).
	 *  This is the analog of the consumeToken method.  Again, the ID is
	 *  the hashCode usually of the node so it only works if hashCode is
	 *  not implemented.
	 */
	public void consumeNode(int ID, String text, int type);

	/** The tree parser looked ahead */
	public void LT(int i, int ID, String text, int type);

	/** The tree parser has popped back up from the child list to the
	 *  root node.
	 */
	public void goUp();

	/** The tree parser has descended to the first child of a the current
	 *  root node.
	 */
	public void goDown();

* Added DebugTreeNodeStream and DebugTreeParser classes

* Added ctor because the debug tree node stream will need to ask quesitons about nodes and since  nodes are just Object, it needs an adaptor to decode the nodes and get text/type info for the debugger.

public CommonTreeNodeStream(TreeAdaptor adaptor, Tree tree);

* added getter to TreeNodeStream:
	public TreeAdaptor getTreeAdaptor();

* Implemented getText/getType in CommonTreeAdaptor.

* Added TraceDebugEventListener that can dump all events to stdout.

* I broke down and make Tree implement getText

* tree rewrites now gen location debug events.

* added AST debug events to listener; added blank listener for convenience

* updated debug events to send begin/end backtrack events for debugging

* with a : (b->b) ('+' b -> ^(PLUS $a b))* ; you get b[0] each time as
  there is no loop in rewrite rule itself.  Need to know context that
  the -> is inside the rule and hence b means last value of b not all
  values.

* Bug in TokenRewriteStream; ops at indexes < start index blocked proper op.

* Actions in ST rewrites "-> ({$op})()" were not translated

* Added new action name:

@rulecatch {
catch (RecognitionException re) {
    reportError(re);
    recover(input,re);
}
catch (Throwable t) {
    System.err.println(t);
}
}
Overrides rule catch stuff.

* Isolated $ refs caused exception

3.0ea8 - March 11, 2006

* added @finally {...} action like @init for rules.  Executes in
  finally block (java target) after all other stuff like rule memoization.
  No code changes needs; ST just refs a new action:
      <ruleDescriptor.actions.finally>

* hideous bug fixed: PLUS='+' didn't result in '+' rule in lexer

* TokenRewriteStream didn't do toString() right when no rewrites had been done.

* lexer errors in interpreter were not printed properly

* bitsets are dumped in hex not decimal now for FOLLOW sets

* /* epsilon */ is not printed now when printing out grammars with empty alts

* Fixed another bug in tree rewrite stuff where it was checking that elements
  had at least one element.  Strange...commented out for now to see if I can remember what's up.

* Tree rewrites had problems when you didn't have x+=FOO variables.  Rules
  like this work now:

  a : (x=ID)? y=ID -> ($x $y)?;

* filter=true for lexers turns on k=1 and backtracking for every token
  alternative.  Put the rules in priority order.

* added getLine() etc... to Tree to support better error reporting for
  trees.  Added MismatchedTreeNodeException.

* $templates::foo() is gone.  added % as special template symbol.
  %foo(a={},b={},...) ctor (even shorter than $templates::foo(...))
  %({name-expr})(a={},...) indirect template ctor reference

  The above are parsed by antlr.g and translated by codegen.g
  The following are parsed manually here:

  %{string-expr} anonymous template from string expr
  %{expr}.y = z; template attribute y of StringTemplate-typed expr to z
  %x.y = z; set template attribute y of x (always set never get attr)
            to z [languages like python without ';' must still use the
            ';' which the code generator is free to remove during code gen]

* -> ({expr})(a={},...) notation for indirect template rewrite.
  expr is the name of the template.

* $x[i]::y and $x[-i]::y notation for accesssing absolute scope stack
  indexes and relative negative scopes.  $x[-1]::y is the y attribute
  of the previous scope (stack top - 1).

* filter=true mode for lexers; can do this now...upon mismatch, just
  consumes a char and tries again:
lexer grammar FuzzyJava;
options {filter=true;}

FIELD
    :   TYPE WS? name=ID WS? (';'|'=')
        {System.out.println("found var "+$name.text);}
    ;

* refactored char streams so ANTLRFileStream is now a subclass of
  ANTLRStringStream.

* char streams for lexer now allowed nested backtracking in lexer.

* added TokenLabelType for lexer/parser for all token labels

* line numbers for error messages were not updated properly in antlr.g
  for strings, char literals and <<...>>

* init action in lexer rules was before the type,start,line,... decls.

* Tree grammars can now specify output; I've only tested output=templat
  though.

* You can reference EOF now in the parser and lexer.  It's just token type
  or char value -1.

* Bug fix: $ID refs in the *lexer* were all messed up.  Cleaned up the
  set of properties available...

* Bug fix: .st not found in rule ref when rule has scope:
field
scope {
	StringTemplate funcDef;
}
    :   ...
	{$field::funcDef = $field.st;}
    ;
it gets field_stack.st instead

* return in backtracking must return retval or null if return value.

* $property within a rule now works like $text, $st, ...

* AST/Template Rewrites were not gated by backtracking==0 so they
  executed even when guessing.  Auto AST construction is now gated also.

* CommonTokenStream was somehow returning tokens not text in toString()

* added useful methods to runtime.BitSet and also to CommonToken so you can
  update the text.  Added nice Token stream method:

  /** Given a start and stop index, return a List of all tokens in
   *  the token type BitSet.  Return null if no tokens were found.  This
   *  method looks at both on and off channel tokens.
   */
  public List getTokens(int start, int stop, BitSet types);

* literals are now passed in the .tokens files so you can ref them in
  tree parses, for example.

* added basic exception handling; no labels, just general catches:

a : {;}A | B ;
        exception
                catch[RecognitionException re] {
                        System.out.println("recog error");
                }
                catch[Exception e] {
                        System.out.println("error");
                }

* Added method to TokenStream:
  public String toString(Token start, Token stop);

* antlr generates #src lines in lexer grammars generated from combined grammars
  so error messages refer to original file.

* lexers generated from combined grammars now use originally formatting.

* predicates have $x.y stuff translated now.  Warning: predicates might be
  hoisted out of context.

* return values in return val structs are now public.

* output=template with return values on rules was broken.  I assume return values with ASTs was broken too.  Fixed.

3.0ea7 - December 14, 2005

* Added -print option to print out grammar w/o actions

* Renamed BaseParser to be BaseRecognizer and even made Lexer derive from
  this; nice as it now shares backtracking support code.

* Added syntactic predicates (...)=>.  See December 4, 2005 entry:

  http://www.antlr.org/blog/antlr3/lookahead.tml

  Note that we have a new option for turning off rule memoization during
  backtracking:

  -nomemo        when backtracking don't generate memoization code

* Predicates are now tested in order that you specify the alts.  If you
  leave the last alt "naked" (w/o pred), it will assume a true pred rather
  than union of other preds.

* Added gated predicates "{p}?=>" that literally turn off a production whereas
disambiguating predicates are only hoisted into the predictor when syntax alone
is not sufficient to uniquely predict alternatives.

A : {p}?  => "a" ;
B : {!p}? => ("a"|"b")+ ;

* bug fixed related to predicates in predictor
lexer grammar w;
A : {p}? "a" ;
B : {!p}? ("a"|"b")+ ;
DFA is correct.  A state splits for input "a" on the pred.
Generated code though was hosed.  No pred tests in prediction code!
I added testLexerPreds() and others in TestSemanticPredicateEvaluation.java

* added execAction template in case we want to do something in front of
  each action execution or something.

* left-recursive cycles from rules w/o decisions were not detected.

* undefined lexer rules were not announced! fixed.

* unreachable messages for Tokens rule now indicate rule name not alt. E.g.,

  Ruby.lexer.g:24:1: The following token definitions are unreachable: IVAR

* nondeterminism warnings improved for Tokens rule:

Ruby.lexer.g:10:1: Multiple token rules can match input such as ""0".."9"": INT, FLOAT
As a result, tokens(s) FLOAT were disabled for that input


* DOT diagrams didn't show escaped char properly.

* Char/string literals are now all 'abc' not "abc".

* action syntax changed "@scope::actionname {action}" where scope defaults
  to "parser" if parser grammar or combined grammar, "lexer" if lexer grammar,
  and "treeparser" if tree grammar.  The code generation targets decide
  what scopes are available.  Each "scope" yields a hashtable for use in
  the output templates.  The scopes full of actions are sent to all output
  file templates (currently headerFile and outputFile) as attribute actions.
  Then you can reference <actions.scope> to get the map of actions associated
  with scope and <actions.parser.header> to get the parser's header action
  for example.  This should be very flexible.  The target should only have
  to define which scopes are valid, but the action names should be variable
  so we don't have to recompile ANTLR to add actions to code gen templates.

  grammar T;
  options {language=Java;}
  @header { package foo; }
  @parser::stuff { int i; } // names within scope not checked; target dependent
  @members { int i; }
  @lexer::header {head}
  @lexer::members { int j; }
  @headerfile::blort {...} // error: this target doesn't have headerfile
  @treeparser::members {...} // error: this is not a tree parser
  a
  @init {int i;}
    : ID
    ;
  ID : 'a'..'z';

  For now, the Java target uses members and header as a valid name.  Within a
  rule, the init action name is valid.

* changed $dynamicscope.value to $dynamicscope::value even if value is defined
  in same rule such as $function::name where rule function defines name.

* $dynamicscope gets you the stack

* rule scopes go like this now:

  rule
  scope {...}
  scope slist,Symbols;
  	: ...
	;

* Created RuleReturnScope as a generic rule return value.  Makes it easier
  to do this:
    RuleReturnScope r = parser.program();
    System.out.println(r.getTemplate().toString());

* $template, $tree, $start, etc...

* $r.x in current rule.  $r is ignored as fully-qualified name. $r.start works too

* added warning about $r referring to both return value of rule and dynamic scope of rule

* integrated StringTemplate in a very simple manner

Syntax:
-> template(arglist) "..."
-> template(arglist) <<...>>
-> namedTemplate(arglist)
-> {free expression}
-> // empty

Predicate syntax:
a : A B -> {p1}? foo(a={$A.text})
        -> {p2}? foo(a={$B.text})
        -> // return nothing

An arg list is just a list of template attribute assignments to actions in curlies.

There is a setTemplateLib() method for you to use with named template rewrites.

Use a new option:

grammar t;
options {output=template;}
...

This all should work for tree grammars too, but I'm still testing.

* fixed bugs where strings were improperly escaped in exceptions, comments, etc..  For example, newlines came out as newlines not the escaped version

3.0ea6 - November 13, 2005

* turned off -debug/-profile, which was on by default

* completely refactored the output templates; added some missing templates.

* dramatically improved infinite recursion error messages (actually
  left-recursion never even was printed out before).

* wasn't printing dangling state messages when it reanalyzes with k=1.

* fixed a nasty bug in the analysis engine dealing with infinite recursion.
  Spent all day thinking about it and cleaned up the code dramatically.
  Bug fixed and software is more powerful and I understand it better! :)

* improved verbose DFA nodes; organized by alt

* got much better random phrase generation.  For example:

 $ java org.antlr.tool.RandomPhrase simple.g program
 int Ktcdn ';' method wh '(' ')' '{' return 5 ';' '}'

* empty rules like "a : ;" generated code that didn't compile due to
  try/catch for RecognitionException.  Generated code couldn't possibly
  throw that exception.

* when printing out a grammar, such as in comments in generated code,
  ANTLR didn't print ast suffix stuff back out for literals.

* This never exited loop:
  DATA : (options {greedy=false;}: .* '\n' )* '\n' '.' ;
  and now it works due to new default nongreedy .*  Also this works:
  DATA : (options {greedy=false;}: .* '\n' )* '.' ;

* Dot star ".*" syntax didn't work; in lexer it is nongreedy by
  default.  In parser it is on greedy but also k=1 by default.  Added
  unit tests.  Added blog entry to describe.

* ~T where T is the only token yielded an empty set but no error

* Used to generate unreachable message here:

  parser grammar t;
  a : ID a
    | ID
    ;

  z.g:3:11: The following alternatives are unreachable: 2

  In fact it should really be an error; now it generates:

  no start rule in grammar t (no rule can obviously be followed by EOF)

  Per next change item, ANTLR cannot know that EOF follows rule 'a'.

* added error message indicating that ANTLR can't figure out what your
  start rule is.  Required to properly generate code in some cases.

* validating semantic predicates now work (if they are false, they
  throw a new FailedPredicateException

* two hideous bug fixes in the IntervalSet, which made analysis go wrong
  in a few cases.  Thanks to Oliver Zeigermann for finding lots of bugs
  and making suggested fixes (including the next two items)!

* cyclic DFAs are now nonstatic and hence can access instance variables

* labels are now allowed on lexical elements (in the lexer)

* added some internal debugging options

* ~'a'* and ~('a')* were not working properly; refactored antlr.g grammar

3.0ea5 - July 5, 2005

* Using '\n' in a parser grammar resulted in a nonescaped version of '\n' in the token names table making compilation fail.  I fixed this by reorganizing/cleaning up portion of ANTLR that deals with literals.  See comment org.antlr.codegen.Target.

* Target.getMaxCharValue() did not use the appropriate max value constant.

* ALLCHAR was a constant when it should use the Target max value def.  set complement for wildcard also didn't use the Target def.  Generally cleaned up the max char value stuff.

* Code gen didn't deal with ASTLabelType properly...I think even the 3.0ea7 example tree parser was broken! :(

* Added a few more unit tests dealing with escaped literals

3.0ea4 - June 29, 2005

* tree parsers work; added CommonTreeNodeStream.  See simplecTreeParser
  example in examples-v3 tarball.

* added superClass and ASTLabelType options

* refactored Parser to have a BaseParser and added TreeParser

* bug fix: actions being dumped in description strings; compile errors
  resulted

3.0ea3 - June 23, 2005

Enhancements

* Automatic tree construction operators are in: ! ^ ^^

* Tree construction rewrite rules are in
	-> {pred1}? rewrite1
	-> {pred2}? rewrite2
	...
	-> rewriteN

  The rewrite rules may be elements like ID, expr, $label, {node expr}
  and trees ^( <root> <children> ).  You have have (...)?, (...)*, (...)+
  subrules as well.

  You may have rewrites in subrules not just at outer level of rule, but
  any -> rewrite forces auto AST construction off for that alternative
  of that rule.

  To avoid cycles, copy semantics are used:

  r : INT -> INT INT ;

  means make two new nodes from the same INT token.

  Repeated references to a rule element implies a copy for at least one
  tree:

  a : atom -> ^(atom atom) ; // NOT CYCLE! (dup atom tree)

* $ruleLabel.tree refers to tree created by matching the labeled element.

* A description of the blocks/alts is generated as a comment in output code

* A timestamp / signature is put at top of each generated code file

3.0ea2 - June 12, 2005

Bug fixes

* Some error messages were missing the stackTrace parameter

* Removed the file locking mechanism as it's not cross platform

* Some absolute vs relative path name problems with writing output
  files.  Rules are now more concrete.  -o option takes precedence
  // -o /tmp /var/lib/t.g => /tmp/T.java
  // -o subdir/output /usr/lib/t.g => subdir/output/T.java
  // -o . /usr/lib/t.g => ./T.java
  // -o /tmp subdir/t.g => /tmp/subdir/t.g
  // If they didn't specify a -o dir so just write to location
  // where grammar is, absolute or relative

* does error checking on unknown option names now

* Using just language code not locale name for error message file.  I.e.,
  the default (and for any English speaking locale) is en.stg not en_US.stg
  anymore.

* The error manager now asks the Tool to panic rather than simply doing
  a System.exit().

* Lots of refactoring concerning grammar, rule, subrule options.  Now
  detects invalid options.

3.0ea1 - June 1, 2005

Initial early access release