diff --git a/tool/src/org/antlr/v4/Tool.java b/tool/src/org/antlr/v4/Tool.java
index bdd892ded..700ffd28c 100644
--- a/tool/src/org/antlr/v4/Tool.java
+++ b/tool/src/org/antlr/v4/Tool.java
@@ -42,6 +42,9 @@ import org.antlr.v4.parse.GrammarASTAdaptor;
 import org.antlr.v4.parse.ToolANTLRParser;
 import org.antlr.v4.semantics.SemanticPipeline;
 import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarASTErrorNode;
+import org.antlr.v4.tool.ast.GrammarRootAST;
 import org.stringtemplate.v4.STGroup;
 
 import java.io.*;
@@ -215,7 +218,7 @@ public class Tool {
 	public void processGrammarsOnCommandLine() {
 		for (String fileName : grammarFiles) {
 			GrammarAST t = loadGrammar(fileName);
-			if ( t==null || t instanceof GrammarASTErrorNode ) return; // came back as error node
+			if ( t==null || t instanceof GrammarASTErrorNode) return; // came back as error node
 			if ( ((GrammarRootAST)t).hasErrors ) return;
 			GrammarRootAST ast = (GrammarRootAST)t;
 
@@ -348,7 +351,7 @@ public class Tool {
 			p.setTreeAdaptor(adaptor);
 			ParserRuleReturnScope r = p.grammarSpec();
 			GrammarRootAST root = (GrammarRootAST)r.getTree();
-			if ( root instanceof GrammarRootAST ) {
+			if ( root instanceof GrammarRootAST) {
 				root.hasErrors = p.getNumberOfSyntaxErrors()>0;
 				root.tokens = tokens;
 			}
diff --git a/tool/src/org/antlr/v4/automata/ATNFactory.java b/tool/src/org/antlr/v4/automata/ATNFactory.java
index 96921db39..0c6e5d460 100644
--- a/tool/src/org/antlr/v4/automata/ATNFactory.java
+++ b/tool/src/org/antlr/v4/automata/ATNFactory.java
@@ -29,8 +29,9 @@
 
 package org.antlr.v4.automata;
 
-import org.antlr.v4.runtime.atn.*;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.runtime.atn.ATN;
+import org.antlr.v4.runtime.atn.ATNState;
+import org.antlr.v4.tool.ast.*;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/automata/LexerATNFactory.java b/tool/src/org/antlr/v4/automata/LexerATNFactory.java
index 8908f05ad..b7abf837a 100644
--- a/tool/src/org/antlr/v4/automata/LexerATNFactory.java
+++ b/tool/src/org/antlr/v4/automata/LexerATNFactory.java
@@ -34,7 +34,11 @@ import org.antlr.v4.misc.CharSupport;
 import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.runtime.atn.*;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.LexerGrammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TerminalAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/automata/ParserATNFactory.java b/tool/src/org/antlr/v4/automata/ParserATNFactory.java
index c8a965006..31e20c579 100644
--- a/tool/src/org/antlr/v4/automata/ParserATNFactory.java
+++ b/tool/src/org/antlr/v4/automata/ParserATNFactory.java
@@ -41,7 +41,11 @@ import org.antlr.v4.parse.GrammarASTAdaptor;
 import org.antlr.v4.runtime.atn.*;
 import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.semantics.UseDefAnalyzer;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ErrorManager;
+import org.antlr.v4.tool.ErrorType;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.*;
 
 import java.lang.reflect.Constructor;
 import java.util.Collection;
diff --git a/tool/src/org/antlr/v4/automata/TreeParserATNFactory.java b/tool/src/org/antlr/v4/automata/TreeParserATNFactory.java
index 3a3637ad2..86835b5ca 100644
--- a/tool/src/org/antlr/v4/automata/TreeParserATNFactory.java
+++ b/tool/src/org/antlr/v4/automata/TreeParserATNFactory.java
@@ -29,12 +29,16 @@
 
 package org.antlr.v4.automata;
 
-import org.antlr.v4.runtime.*;
+import org.antlr.v4.runtime.RuleContext;
+import org.antlr.v4.runtime.Token;
 import org.antlr.v4.runtime.atn.*;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TreePatternAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /** Build ATNs for tree grammars */
 public class TreeParserATNFactory extends ParserATNFactory {
diff --git a/tool/src/org/antlr/v4/codegen/ActionTranslator.java b/tool/src/org/antlr/v4/codegen/ActionTranslator.java
index c9769cea7..a909565cb 100644
--- a/tool/src/org/antlr/v4/codegen/ActionTranslator.java
+++ b/tool/src/org/antlr/v4/codegen/ActionTranslator.java
@@ -35,7 +35,11 @@ import org.antlr.v4.codegen.model.RuleFunction;
 import org.antlr.v4.codegen.model.actions.*;
 import org.antlr.v4.parse.ActionSplitter;
 import org.antlr.v4.parse.ActionSplitterListener;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Attribute;
+import org.antlr.v4.tool.ErrorType;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
 
 import java.lang.reflect.Constructor;
 import java.util.ArrayList;
diff --git a/tool/src/org/antlr/v4/codegen/BlankOutputModelFactory.java b/tool/src/org/antlr/v4/codegen/BlankOutputModelFactory.java
index 7c295c7bc..f8d4d9eb1 100644
--- a/tool/src/org/antlr/v4/codegen/BlankOutputModelFactory.java
+++ b/tool/src/org/antlr/v4/codegen/BlankOutputModelFactory.java
@@ -32,7 +32,12 @@ package org.antlr.v4.codegen;
 import org.antlr.v4.codegen.model.*;
 import org.antlr.v4.codegen.model.ast.*;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.BlockAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.PredAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/CodeGeneratorExtension.java b/tool/src/org/antlr/v4/codegen/CodeGeneratorExtension.java
index b0abece61..45e007b99 100644
--- a/tool/src/org/antlr/v4/codegen/CodeGeneratorExtension.java
+++ b/tool/src/org/antlr/v4/codegen/CodeGeneratorExtension.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen;
 
 import org.antlr.v4.codegen.model.*;
 import org.antlr.v4.codegen.model.ast.*;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/DefaultOutputModelFactory.java b/tool/src/org/antlr/v4/codegen/DefaultOutputModelFactory.java
index 4a791b18f..032cf300d 100644
--- a/tool/src/org/antlr/v4/codegen/DefaultOutputModelFactory.java
+++ b/tool/src/org/antlr/v4/codegen/DefaultOutputModelFactory.java
@@ -30,10 +30,14 @@
 package org.antlr.v4.codegen;
 
 import org.antlr.v4.codegen.model.*;
-import org.antlr.v4.codegen.model.decl.*;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.codegen.model.decl.CodeBlock;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /** Create output objects for elements *within* rule functions except
  *  buildOutputModel() which builds outer/root model object and any
diff --git a/tool/src/org/antlr/v4/codegen/OutputModelController.java b/tool/src/org/antlr/v4/codegen/OutputModelController.java
index 0cc509ec7..fd26a008f 100644
--- a/tool/src/org/antlr/v4/codegen/OutputModelController.java
+++ b/tool/src/org/antlr/v4/codegen/OutputModelController.java
@@ -33,10 +33,19 @@ import org.antlr.runtime.tree.CommonTreeNodeStream;
 import org.antlr.v4.codegen.model.*;
 import org.antlr.v4.codegen.model.ast.*;
 import org.antlr.v4.codegen.model.decl.CodeBlock;
-import org.antlr.v4.parse.*;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.parse.GrammarASTAdaptor;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.BlockAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.PredAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
 
 /** This receives events from SourceGenTriggers.g and asks factory to do work.
  *  Then runs extensions in order on resulting SrcOps to get final list.
diff --git a/tool/src/org/antlr/v4/codegen/OutputModelFactory.java b/tool/src/org/antlr/v4/codegen/OutputModelFactory.java
index 0ac120d2d..573565e4e 100644
--- a/tool/src/org/antlr/v4/codegen/OutputModelFactory.java
+++ b/tool/src/org/antlr/v4/codegen/OutputModelFactory.java
@@ -33,7 +33,13 @@ import org.antlr.v4.codegen.model.*;
 import org.antlr.v4.codegen.model.ast.*;
 import org.antlr.v4.codegen.model.decl.CodeBlock;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.BlockAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.PredAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/ParserASTExtension.java b/tool/src/org/antlr/v4/codegen/ParserASTExtension.java
index 8e5fc7976..e855e009e 100644
--- a/tool/src/org/antlr/v4/codegen/ParserASTExtension.java
+++ b/tool/src/org/antlr/v4/codegen/ParserASTExtension.java
@@ -31,11 +31,11 @@ package org.antlr.v4.codegen;
 
 import org.antlr.v4.codegen.model.*;
 import org.antlr.v4.codegen.model.ast.*;
-import org.antlr.v4.codegen.model.ast.RuleAST;
 import org.antlr.v4.codegen.model.decl.*;
 import org.antlr.v4.misc.Utils;
 import org.antlr.v4.parse.ANTLRParser;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/ParserFactory.java b/tool/src/org/antlr/v4/codegen/ParserFactory.java
index 46ba61ecf..f2699ecd7 100644
--- a/tool/src/org/antlr/v4/codegen/ParserFactory.java
+++ b/tool/src/org/antlr/v4/codegen/ParserFactory.java
@@ -39,7 +39,9 @@ import org.antlr.v4.runtime.atn.PlusBlockStartState;
 import org.antlr.v4.runtime.atn.StarLoopEntryState;
 import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.semantics.UseDefAnalyzer;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.*;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/Target.java b/tool/src/org/antlr/v4/codegen/Target.java
index 676d43f2e..374b6d5ed 100644
--- a/tool/src/org/antlr/v4/codegen/Target.java
+++ b/tool/src/org/antlr/v4/codegen/Target.java
@@ -34,8 +34,8 @@ import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.runtime.Lexer;
 import org.antlr.v4.runtime.Token;
 import org.antlr.v4.tool.Grammar;
-import org.antlr.v4.tool.GrammarAST;
 import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.GrammarAST;
 import org.stringtemplate.v4.ST;
 
 /** */
diff --git a/tool/src/org/antlr/v4/codegen/TreeParserFactory.java b/tool/src/org/antlr/v4/codegen/TreeParserFactory.java
index 07841a773..8dea27379 100644
--- a/tool/src/org/antlr/v4/codegen/TreeParserFactory.java
+++ b/tool/src/org/antlr/v4/codegen/TreeParserFactory.java
@@ -36,7 +36,7 @@ import org.antlr.v4.codegen.model.decl.Decl;
 import org.antlr.v4.codegen.model.decl.NodeDecl;
 import org.antlr.v4.codegen.model.decl.NodeListDecl;
 import org.antlr.v4.codegen.model.decl.TokenListDecl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/Wildcard.java b/tool/src/org/antlr/v4/codegen/Wildcard.java
index 0d489e540..a937794b5 100644
--- a/tool/src/org/antlr/v4/codegen/Wildcard.java
+++ b/tool/src/org/antlr/v4/codegen/Wildcard.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen;
 
 import org.antlr.v4.codegen.model.MatchToken;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class Wildcard extends MatchToken {
 	public Wildcard(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/Action.java b/tool/src/org/antlr/v4/codegen/model/Action.java
index 18f44aa1e..fe37ff7c4 100644
--- a/tool/src/org/antlr/v4/codegen/model/Action.java
+++ b/tool/src/org/antlr/v4/codegen/model/Action.java
@@ -29,9 +29,11 @@
 
 package org.antlr.v4.codegen.model;
 
-import org.antlr.v4.codegen.*;
+import org.antlr.v4.codegen.ActionTranslator;
+import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.actions.ActionChunk;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/AltBlock.java b/tool/src/org/antlr/v4/codegen/model/AltBlock.java
index 6cfeadd64..94e93841d 100644
--- a/tool/src/org/antlr/v4/codegen/model/AltBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/AltBlock.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.BlockStartState;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/ArgAction.java b/tool/src/org/antlr/v4/codegen/model/ArgAction.java
index 172867a0c..e8fffef61 100644
--- a/tool/src/org/antlr/v4/codegen/model/ArgAction.java
+++ b/tool/src/org/antlr/v4/codegen/model/ArgAction.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class ArgAction extends Action {
 	/** Context type of invoked rule */
diff --git a/tool/src/org/antlr/v4/codegen/model/Choice.java b/tool/src/org/antlr/v4/codegen/model/Choice.java
index f30b3282a..39651d3be 100644
--- a/tool/src/org/antlr/v4/codegen/model/Choice.java
+++ b/tool/src/org/antlr/v4/codegen/model/Choice.java
@@ -30,12 +30,14 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.codegen.model.decl.*;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.codegen.model.decl.TokenTypeDecl;
 import org.antlr.v4.misc.Utils;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /** The class hierarchy underneath SrcOp is pretty deep but makes sense that,
  *  for example LL1StarBlock is a kind of LL1Loop which is a kind of Choice.
diff --git a/tool/src/org/antlr/v4/codegen/model/ForcedAction.java b/tool/src/org/antlr/v4/codegen/model/ForcedAction.java
index b21cc0bd7..1e60014dd 100644
--- a/tool/src/org/antlr/v4/codegen/model/ForcedAction.java
+++ b/tool/src/org/antlr/v4/codegen/model/ForcedAction.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class ForcedAction extends Action {
 	public ForcedAction(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/InvokeRule.java b/tool/src/org/antlr/v4/codegen/model/InvokeRule.java
index ffc91430d..c4b622bdb 100644
--- a/tool/src/org/antlr/v4/codegen/model/InvokeRule.java
+++ b/tool/src/org/antlr/v4/codegen/model/InvokeRule.java
@@ -29,13 +29,19 @@
 
 package org.antlr.v4.codegen.model;
 
-import org.antlr.v4.codegen.*;
+import org.antlr.v4.codegen.ActionTranslator;
+import org.antlr.v4.codegen.CodeGenerator;
+import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.actions.ActionChunk;
-import org.antlr.v4.codegen.model.decl.*;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.codegen.model.decl.RuleContextDecl;
+import org.antlr.v4.codegen.model.decl.RuleContextListDecl;
 import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.runtime.atn.RuleTransition;
 import org.antlr.v4.runtime.misc.OrderedHashSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1AltBlock.java b/tool/src/org/antlr/v4/codegen/model/LL1AltBlock.java
index 26aa8fd26..4c12444c7 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1AltBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1AltBlock.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.DecisionState;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1Choice.java b/tool/src/org/antlr/v4/codegen/model/LL1Choice.java
index 76be95ea2..a4cc8aa46 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1Choice.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1Choice.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1Loop.java b/tool/src/org/antlr/v4/codegen/model/LL1Loop.java
index e62c56ec3..581d291f1 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1Loop.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1Loop.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlock.java b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlock.java
index 71bc98493..ad28795cc 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlock.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java
index 3d2705e2d..06703dcb0 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1OptionalBlockSingleAlt.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.DecisionState;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1PlusBlock.java b/tool/src/org/antlr/v4/codegen/model/LL1PlusBlock.java
index c746e9333..e837b60ac 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1PlusBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1PlusBlock.java
@@ -34,7 +34,7 @@ import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.PlusBlockStartState;
 import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.tool.Grammar;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1PlusBlockSingleAlt.java b/tool/src/org/antlr/v4/codegen/model/LL1PlusBlockSingleAlt.java
index 19ff25d0b..c50995601 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1PlusBlockSingleAlt.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1PlusBlockSingleAlt.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.PlusBlockStartState;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1StarBlock.java b/tool/src/org/antlr/v4/codegen/model/LL1StarBlock.java
index b7cb313ad..5fcd22612 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1StarBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1StarBlock.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.StarLoopEntryState;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LL1StarBlockSingleAlt.java b/tool/src/org/antlr/v4/codegen/model/LL1StarBlockSingleAlt.java
index a1ad68743..861888763 100644
--- a/tool/src/org/antlr/v4/codegen/model/LL1StarBlockSingleAlt.java
+++ b/tool/src/org/antlr/v4/codegen/model/LL1StarBlockSingleAlt.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.StarLoopEntryState;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/LexerFile.java b/tool/src/org/antlr/v4/codegen/model/LexerFile.java
index cdd8e6151..afa4fb43c 100644
--- a/tool/src/org/antlr/v4/codegen/model/LexerFile.java
+++ b/tool/src/org/antlr/v4/codegen/model/LexerFile.java
@@ -30,9 +30,11 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 public class LexerFile extends OutputModelObject {
 	public String fileName;
@@ -50,4 +52,4 @@ public class LexerFile extends OutputModelObject {
 			namedActions.put(name, new Action(factory, ast));
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/tool/src/org/antlr/v4/codegen/model/ListenerFile.java b/tool/src/org/antlr/v4/codegen/model/ListenerFile.java
index bcbe20bc7..88703135a 100644
--- a/tool/src/org/antlr/v4/codegen/model/ListenerFile.java
+++ b/tool/src/org/antlr/v4/codegen/model/ListenerFile.java
@@ -1,9 +1,12 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /** A model object representing a parse tree listener file.
  *  These are the rules specific events triggered by a parse tree visitor.
diff --git a/tool/src/org/antlr/v4/codegen/model/Loop.java b/tool/src/org/antlr/v4/codegen/model/Loop.java
index 9e3766643..a24138028 100644
--- a/tool/src/org/antlr/v4/codegen/model/Loop.java
+++ b/tool/src/org/antlr/v4/codegen/model/Loop.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchDOWN.java b/tool/src/org/antlr/v4/codegen/model/MatchDOWN.java
index 58dda3ad4..defffb3e7 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchDOWN.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchDOWN.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class MatchDOWN extends RuleElement {
 	public MatchDOWN(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchNotSet.java b/tool/src/org/antlr/v4/codegen/model/MatchNotSet.java
index a99677d29..9e8433b39 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchNotSet.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchNotSet.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class MatchNotSet extends MatchSet {
 	public MatchNotSet(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchSet.java b/tool/src/org/antlr/v4/codegen/model/MatchSet.java
index 79a571c70..e177a54fc 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchSet.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchSet.java
@@ -30,9 +30,10 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.codegen.model.decl.*;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.codegen.model.decl.TokenTypeDecl;
 import org.antlr.v4.runtime.atn.SetTransition;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class MatchSet extends MatchToken {
 	@ModelElement public TestSetInline expr;
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchToken.java b/tool/src/org/antlr/v4/codegen/model/MatchToken.java
index 80ab012d3..76b51cfa7 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchToken.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchToken.java
@@ -29,11 +29,15 @@
 
 package org.antlr.v4.codegen.model;
 
-import org.antlr.v4.codegen.*;
+import org.antlr.v4.codegen.CodeGenerator;
+import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TerminalAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /** */
 public class MatchToken extends RuleElement implements LabeledOp {
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchTree.java b/tool/src/org/antlr/v4/codegen/model/MatchTree.java
index 8865b1006..8ae6e02c2 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchTree.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchTree.java
@@ -31,10 +31,13 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.misc.Utils;
-import org.antlr.v4.runtime.*;
-import org.antlr.v4.runtime.atn.*;
+import org.antlr.v4.runtime.RuleContext;
+import org.antlr.v4.runtime.Token;
+import org.antlr.v4.runtime.atn.ATNState;
+import org.antlr.v4.runtime.atn.LL1Analyzer;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TreePatternAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/MatchUP.java b/tool/src/org/antlr/v4/codegen/model/MatchUP.java
index 316104506..cd3435103 100644
--- a/tool/src/org/antlr/v4/codegen/model/MatchUP.java
+++ b/tool/src/org/antlr/v4/codegen/model/MatchUP.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class MatchUP extends RuleElement {
 	public MatchUP(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/OptionalBlock.java b/tool/src/org/antlr/v4/codegen/model/OptionalBlock.java
index 8f6be301d..1cea7ba98 100644
--- a/tool/src/org/antlr/v4/codegen/model/OptionalBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/OptionalBlock.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/OutputModelObject.java b/tool/src/org/antlr/v4/codegen/model/OutputModelObject.java
index bd492dfb4..370169a8b 100644
--- a/tool/src/org/antlr/v4/codegen/model/OutputModelObject.java
+++ b/tool/src/org/antlr/v4/codegen/model/OutputModelObject.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public abstract class OutputModelObject {
diff --git a/tool/src/org/antlr/v4/codegen/model/ParserFile.java b/tool/src/org/antlr/v4/codegen/model/ParserFile.java
index 23d9ad063..c787bbe63 100644
--- a/tool/src/org/antlr/v4/codegen/model/ParserFile.java
+++ b/tool/src/org/antlr/v4/codegen/model/ParserFile.java
@@ -30,9 +30,11 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 /** */
 public class ParserFile extends OutputModelObject {
diff --git a/tool/src/org/antlr/v4/codegen/model/PlusBlock.java b/tool/src/org/antlr/v4/codegen/model/PlusBlock.java
index 2e9bd4ef4..44e1bfba2 100644
--- a/tool/src/org/antlr/v4/codegen/model/PlusBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/PlusBlock.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.PlusBlockStartState;
 import org.antlr.v4.runtime.atn.PlusLoopbackState;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/RuleElement.java b/tool/src/org/antlr/v4/codegen/model/RuleElement.java
index 5c4ceb404..303731374 100644
--- a/tool/src/org/antlr/v4/codegen/model/RuleElement.java
+++ b/tool/src/org/antlr/v4/codegen/model/RuleElement.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RuleElement extends SrcOp {
 	/** Associated ATN state for this rule elements (action, token, ruleref, ...) */
diff --git a/tool/src/org/antlr/v4/codegen/model/RuleFunction.java b/tool/src/org/antlr/v4/codegen/model/RuleFunction.java
index e495dfb0c..f2582922f 100644
--- a/tool/src/org/antlr/v4/codegen/model/RuleFunction.java
+++ b/tool/src/org/antlr/v4/codegen/model/RuleFunction.java
@@ -38,8 +38,8 @@ import org.antlr.v4.misc.Utils;
 import org.antlr.v4.runtime.atn.ATNState;
 import org.antlr.v4.runtime.misc.OrderedHashSet;
 import org.antlr.v4.tool.Attribute;
-import org.antlr.v4.tool.GrammarAST;
 import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.*;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/SemPred.java b/tool/src/org/antlr/v4/codegen/model/SemPred.java
index 5a1debc5c..a50e0bbb3 100644
--- a/tool/src/org/antlr/v4/codegen/model/SemPred.java
+++ b/tool/src/org/antlr/v4/codegen/model/SemPred.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class SemPred extends Action {
diff --git a/tool/src/org/antlr/v4/codegen/model/SrcOp.java b/tool/src/org/antlr/v4/codegen/model/SrcOp.java
index 284d6fb3c..19c775590 100644
--- a/tool/src/org/antlr/v4/codegen/model/SrcOp.java
+++ b/tool/src/org/antlr/v4/codegen/model/SrcOp.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public abstract class SrcOp extends OutputModelObject {
diff --git a/tool/src/org/antlr/v4/codegen/model/StarBlock.java b/tool/src/org/antlr/v4/codegen/model/StarBlock.java
index efaf077d9..c6cadb9bb 100644
--- a/tool/src/org/antlr/v4/codegen/model/StarBlock.java
+++ b/tool/src/org/antlr/v4/codegen/model/StarBlock.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.atn.StarLoopEntryState;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/Sync.java b/tool/src/org/antlr/v4/codegen/model/Sync.java
index dd15e480e..8cf5732fe 100644
--- a/tool/src/org/antlr/v4/codegen/model/Sync.java
+++ b/tool/src/org/antlr/v4/codegen/model/Sync.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class Sync extends SrcOp {
diff --git a/tool/src/org/antlr/v4/codegen/model/TestSetInline.java b/tool/src/org/antlr/v4/codegen/model/TestSetInline.java
index 6b7c23ed2..5785c5f36 100644
--- a/tool/src/org/antlr/v4/codegen/model/TestSetInline.java
+++ b/tool/src/org/antlr/v4/codegen/model/TestSetInline.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class TestSetInline extends SrcOp {
diff --git a/tool/src/org/antlr/v4/codegen/model/ThrowEarlyExitException.java b/tool/src/org/antlr/v4/codegen/model/ThrowEarlyExitException.java
index 289b5e3de..f85fd7958 100644
--- a/tool/src/org/antlr/v4/codegen/model/ThrowEarlyExitException.java
+++ b/tool/src/org/antlr/v4/codegen/model/ThrowEarlyExitException.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class ThrowEarlyExitException extends ThrowRecognitionException {
diff --git a/tool/src/org/antlr/v4/codegen/model/ThrowNoViableAlt.java b/tool/src/org/antlr/v4/codegen/model/ThrowNoViableAlt.java
index 5b957cd23..0a17d21aa 100644
--- a/tool/src/org/antlr/v4/codegen/model/ThrowNoViableAlt.java
+++ b/tool/src/org/antlr/v4/codegen/model/ThrowNoViableAlt.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class ThrowNoViableAlt extends ThrowRecognitionException {
diff --git a/tool/src/org/antlr/v4/codegen/model/ThrowRecognitionException.java b/tool/src/org/antlr/v4/codegen/model/ThrowRecognitionException.java
index fa78609dd..d16ca7fcf 100644
--- a/tool/src/org/antlr/v4/codegen/model/ThrowRecognitionException.java
+++ b/tool/src/org/antlr/v4/codegen/model/ThrowRecognitionException.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.runtime.misc.IntervalSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class ThrowRecognitionException extends SrcOp {
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/ClearElementList.java b/tool/src/org/antlr/v4/codegen/model/ast/ClearElementList.java
index d3bed9005..5318d4352 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/ClearElementList.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/ClearElementList.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class ClearElementList extends SrcOp {
 	public String name;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/ElementASTOp.java b/tool/src/org/antlr/v4/codegen/model/ast/ElementASTOp.java
index 9c2da7c52..8f736dcb7 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/ElementASTOp.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/ElementASTOp.java
@@ -32,7 +32,7 @@ package org.antlr.v4.codegen.model.ast;
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class ElementASTOp extends SrcOp {
 	public Decl label;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteAction.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteAction.java
index 85986edf6..9d3fb5787 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteAction.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteAction.java
@@ -29,10 +29,12 @@
 
 package org.antlr.v4.codegen.model.ast;
 
-import org.antlr.v4.codegen.*;
-import org.antlr.v4.codegen.model.*;
+import org.antlr.v4.codegen.ActionTranslator;
+import org.antlr.v4.codegen.OutputModelFactory;
+import org.antlr.v4.codegen.model.ModelElement;
+import org.antlr.v4.codegen.model.SrcOp;
 import org.antlr.v4.codegen.model.actions.ActionChunk;
-import org.antlr.v4.tool.ActionAST;
+import org.antlr.v4.tool.ast.ActionAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteImagTokenRef.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteImagTokenRef.java
index dff9386af..5bae6da72 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteImagTokenRef.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteImagTokenRef.java
@@ -29,10 +29,13 @@
 
 package org.antlr.v4.codegen.model.ast;
 
-import org.antlr.v4.codegen.*;
-import org.antlr.v4.codegen.model.*;
+import org.antlr.v4.codegen.ActionTranslator;
+import org.antlr.v4.codegen.OutputModelFactory;
+import org.antlr.v4.codegen.model.ModelElement;
+import org.antlr.v4.codegen.model.SrcOp;
 import org.antlr.v4.codegen.model.actions.ActionChunk;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteLabelRef.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteLabelRef.java
index 024c11036..744f344b6 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteLabelRef.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteLabelRef.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RewriteLabelRef extends SrcOp {
 	public String iterName;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteRuleRef.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteRuleRef.java
index 6a4503620..ba6cb8239 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteRuleRef.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteRuleRef.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RewriteRuleRef extends SrcOp {
 	public String iterName;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteSelfRuleLabelRef.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteSelfRuleLabelRef.java
index 4f68d537e..042391eba 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteSelfRuleLabelRef.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteSelfRuleLabelRef.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RewriteSelfRuleLabelRef extends SrcOp {
 	public RewriteSelfRuleLabelRef(OutputModelFactory factory, GrammarAST ast) {
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTokenRef.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTokenRef.java
index b7c54a072..8ba987f88 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTokenRef.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTokenRef.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.SrcOp;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RewriteTokenRef extends SrcOp {
 	public String iterName;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeClosure.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeClosure.java
index bc8252186..e250d692a 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeClosure.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeClosure.java
@@ -30,10 +30,12 @@
 package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.codegen.model.decl.*;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.codegen.model.decl.CodeBlock;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 public class RewriteTreeClosure extends CodeBlock {
 	public List<Decl> iteratorDecls = new ArrayList<Decl>();
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeOptional.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeOptional.java
index 466784e96..78cad7e29 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeOptional.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeOptional.java
@@ -30,10 +30,12 @@
 package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.codegen.model.decl.*;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.codegen.model.decl.CodeBlock;
+import org.antlr.v4.codegen.model.decl.Decl;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 public class RewriteTreeOptional extends CodeBlock {
 	public List<Decl> conditionalDecls = new ArrayList<Decl>();
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeStructure.java b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeStructure.java
index 4b9337b32..0d67dbacf 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeStructure.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RewriteTreeStructure.java
@@ -30,10 +30,11 @@
 package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.codegen.model.*;
+import org.antlr.v4.codegen.model.ModelElement;
+import org.antlr.v4.codegen.model.SrcOp;
 import org.antlr.v4.codegen.model.decl.Decl;
 import org.antlr.v4.runtime.misc.OrderedHashSet;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/RuleAST.java b/tool/src/org/antlr/v4/codegen/model/ast/RuleAST.java
index 259f772ab..247762c9b 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/RuleAST.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/RuleAST.java
@@ -31,10 +31,10 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RuleAST extends ElementASTOp {
 	public RuleAST(OutputModelFactory factory, GrammarAST ast, Decl label) {
 		super(factory, ast, label);
 	}
-}
\ No newline at end of file
+}
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/TokenAST.java b/tool/src/org/antlr/v4/codegen/model/ast/TokenAST.java
index 9a4161661..1053e3c7b 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/TokenAST.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/TokenAST.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 /** */
 public class TokenAST extends ElementASTOp {
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/TrackRuleElement.java b/tool/src/org/antlr/v4/codegen/model/ast/TrackRuleElement.java
index be6b4a355..f5ada7ba1 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/TrackRuleElement.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/TrackRuleElement.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class TrackRuleElement extends ElementASTOp {
 	public String name;
diff --git a/tool/src/org/antlr/v4/codegen/model/ast/TrackTokenElement.java b/tool/src/org/antlr/v4/codegen/model/ast/TrackTokenElement.java
index 59bbe022c..b7a5dc0b6 100644
--- a/tool/src/org/antlr/v4/codegen/model/ast/TrackTokenElement.java
+++ b/tool/src/org/antlr/v4/codegen/model/ast/TrackTokenElement.java
@@ -31,7 +31,7 @@ package org.antlr.v4.codegen.model.ast;
 
 import org.antlr.v4.codegen.OutputModelFactory;
 import org.antlr.v4.codegen.model.decl.Decl;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class TrackTokenElement extends ElementASTOp {
 	public String name;
diff --git a/tool/src/org/antlr/v4/codegen/model/decl/RewriteIteratorDecl.java b/tool/src/org/antlr/v4/codegen/model/decl/RewriteIteratorDecl.java
index 1a831536a..42096c8e8 100644
--- a/tool/src/org/antlr/v4/codegen/model/decl/RewriteIteratorDecl.java
+++ b/tool/src/org/antlr/v4/codegen/model/decl/RewriteIteratorDecl.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.codegen.model.decl;
 
 import org.antlr.v4.codegen.OutputModelFactory;
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class RewriteIteratorDecl extends Decl {
 	public String listName;
diff --git a/tool/src/org/antlr/v4/misc/Utils.java b/tool/src/org/antlr/v4/misc/Utils.java
index c99857a93..f714fc5e7 100644
--- a/tool/src/org/antlr/v4/misc/Utils.java
+++ b/tool/src/org/antlr/v4/misc/Utils.java
@@ -29,10 +29,13 @@
 
 package org.antlr.v4.misc;
 
-import org.antlr.v4.tool.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.lang.reflect.Method;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
 
 /** */
 public class Utils {
diff --git a/tool/src/org/antlr/v4/parse/ANTLRParser.g b/tool/src/org/antlr/v4/parse/ANTLRParser.g
index 7fd01989b..a93291ca7 100644
--- a/tool/src/org/antlr/v4/parse/ANTLRParser.g
+++ b/tool/src/org/antlr/v4/parse/ANTLRParser.g
@@ -131,6 +131,7 @@ tokens {
 package org.antlr.v4.parse;
 
 import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.*;
 }
 
 @members {
diff --git a/tool/src/org/antlr/v4/parse/GrammarASTAdaptor.java b/tool/src/org/antlr/v4/parse/GrammarASTAdaptor.java
index 957220adf..733063ca9 100644
--- a/tool/src/org/antlr/v4/parse/GrammarASTAdaptor.java
+++ b/tool/src/org/antlr/v4/parse/GrammarASTAdaptor.java
@@ -29,9 +29,13 @@
 
 package org.antlr.v4.parse;
 
-import org.antlr.runtime.*;
+import org.antlr.runtime.CommonToken;
+import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.CommonTreeAdaptor;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarASTErrorNode;
+import org.antlr.v4.tool.ast.GrammarASTWithOptions;
+import org.antlr.v4.tool.ast.TerminalAST;
 
 public class GrammarASTAdaptor extends CommonTreeAdaptor {
     org.antlr.runtime.CharStream input; // where we can find chars ref'd by tokens in tree
diff --git a/tool/src/org/antlr/v4/parse/LeftRecursiveRuleAnalyzer.java b/tool/src/org/antlr/v4/parse/LeftRecursiveRuleAnalyzer.java
index fd20ca279..ff53d8637 100644
--- a/tool/src/org/antlr/v4/parse/LeftRecursiveRuleAnalyzer.java
+++ b/tool/src/org/antlr/v4/parse/LeftRecursiveRuleAnalyzer.java
@@ -29,12 +29,18 @@
 
 package org.antlr.v4.parse;
 
-import org.antlr.runtime.*;
+import org.antlr.runtime.CommonToken;
+import org.antlr.runtime.TokenStream;
 import org.antlr.runtime.tree.CommonTreeNodeStream;
 import org.antlr.v4.Tool;
 import org.antlr.v4.codegen.CodeGenerator;
-import org.antlr.v4.tool.*;
-import org.stringtemplate.v4.*;
+import org.antlr.v4.tool.AttributeDict;
+import org.antlr.v4.tool.ErrorType;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.GrammarASTWithOptions;
+import org.stringtemplate.v4.ST;
+import org.stringtemplate.v4.STGroup;
+import org.stringtemplate.v4.STGroupFile;
 
 import java.util.*;
 
diff --git a/tool/src/org/antlr/v4/semantics/ActionSniffer.java b/tool/src/org/antlr/v4/semantics/ActionSniffer.java
index 833be7fbf..fe2171993 100644
--- a/tool/src/org/antlr/v4/semantics/ActionSniffer.java
+++ b/tool/src/org/antlr/v4/semantics/ActionSniffer.java
@@ -29,9 +29,16 @@
 
 package org.antlr.v4.semantics;
 
-import org.antlr.runtime.*;
+import org.antlr.runtime.ANTLRStringStream;
+import org.antlr.runtime.Token;
 import org.antlr.v4.parse.ActionSplitter;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Alternative;
+import org.antlr.v4.tool.ErrorManager;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TerminalAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/semantics/AttributeChecks.java b/tool/src/org/antlr/v4/semantics/AttributeChecks.java
index 21fa567ca..d300a3ccf 100644
--- a/tool/src/org/antlr/v4/semantics/AttributeChecks.java
+++ b/tool/src/org/antlr/v4/semantics/AttributeChecks.java
@@ -34,6 +34,7 @@ import org.antlr.runtime.Token;
 import org.antlr.v4.parse.ActionSplitter;
 import org.antlr.v4.parse.ActionSplitterListener;
 import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.ActionAST;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/semantics/BasicSemanticChecks.java b/tool/src/org/antlr/v4/semantics/BasicSemanticChecks.java
index a3080c4e6..d5a73b74c 100644
--- a/tool/src/org/antlr/v4/semantics/BasicSemanticChecks.java
+++ b/tool/src/org/antlr/v4/semantics/BasicSemanticChecks.java
@@ -31,8 +31,12 @@ package org.antlr.v4.semantics;
 
 import org.antlr.runtime.Token;
 import org.antlr.v4.misc.Utils;
-import org.antlr.v4.parse.*;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.parse.GrammarTreeVisitor;
+import org.antlr.v4.tool.ErrorManager;
+import org.antlr.v4.tool.ErrorType;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.ast.*;
 import org.stringtemplate.v4.misc.MultiMap;
 
 import java.io.File;
diff --git a/tool/src/org/antlr/v4/semantics/RewriteRefs.java b/tool/src/org/antlr/v4/semantics/RewriteRefs.java
index 1279188ef..bd3e6a75f 100644
--- a/tool/src/org/antlr/v4/semantics/RewriteRefs.java
+++ b/tool/src/org/antlr/v4/semantics/RewriteRefs.java
@@ -30,9 +30,12 @@
 package org.antlr.v4.semantics;
 
 import org.antlr.v4.parse.GrammarTreeVisitor;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TerminalAST;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 public class RewriteRefs extends GrammarTreeVisitor {
 	List<GrammarAST> shallow = new ArrayList<GrammarAST>();
diff --git a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
index 1dd9c4d7a..6d48af078 100644
--- a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
+++ b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
@@ -30,9 +30,13 @@
 package org.antlr.v4.semantics;
 
 import org.antlr.v4.parse.ANTLRParser;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.GrammarAST;
 
-import java.util.*;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
 /** Do as much semantic checking as we can and fill in grammar
  *  with rules, actions, and token definitions.
diff --git a/tool/src/org/antlr/v4/semantics/SymbolChecks.java b/tool/src/org/antlr/v4/semantics/SymbolChecks.java
index 2950d7884..75591eb4f 100644
--- a/tool/src/org/antlr/v4/semantics/SymbolChecks.java
+++ b/tool/src/org/antlr/v4/semantics/SymbolChecks.java
@@ -32,6 +32,7 @@ package org.antlr.v4.semantics;
 import org.antlr.runtime.Token;
 import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.*;
 
diff --git a/tool/src/org/antlr/v4/semantics/SymbolCollector.java b/tool/src/org/antlr/v4/semantics/SymbolCollector.java
index 8224807b8..d759508a2 100644
--- a/tool/src/org/antlr/v4/semantics/SymbolCollector.java
+++ b/tool/src/org/antlr/v4/semantics/SymbolCollector.java
@@ -29,10 +29,18 @@
 
 package org.antlr.v4.semantics;
 
-import org.antlr.v4.parse.*;
-import org.antlr.v4.tool.*;
+import org.antlr.v4.parse.GrammarTreeVisitor;
+import org.antlr.v4.parse.ScopeParser;
+import org.antlr.v4.tool.AttributeDict;
+import org.antlr.v4.tool.Grammar;
+import org.antlr.v4.tool.LabelElementPair;
+import org.antlr.v4.tool.Rule;
+import org.antlr.v4.tool.ast.*;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 /** Collects (create) rules, terminals, strings, actions, scopes etc... from AST
  *  side-effects: sets resolver field of asts for actions and
diff --git a/tool/src/org/antlr/v4/semantics/UseDefAnalyzer.java b/tool/src/org/antlr/v4/semantics/UseDefAnalyzer.java
index 20d07e7ba..ca70e8618 100644
--- a/tool/src/org/antlr/v4/semantics/UseDefAnalyzer.java
+++ b/tool/src/org/antlr/v4/semantics/UseDefAnalyzer.java
@@ -29,9 +29,14 @@
 
 package org.antlr.v4.semantics;
 
-import org.antlr.runtime.*;
-import org.antlr.v4.parse.*;
+import org.antlr.runtime.ANTLRStringStream;
+import org.antlr.runtime.Token;
+import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.parse.ActionSplitter;
+import org.antlr.v4.parse.ActionSplitterListener;
 import org.antlr.v4.tool.*;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 import java.util.*;
 
diff --git a/tool/src/org/antlr/v4/tool/Alternative.java b/tool/src/org/antlr/v4/tool/Alternative.java
index a228b6d61..4db43a63b 100644
--- a/tool/src/org/antlr/v4/tool/Alternative.java
+++ b/tool/src/org/antlr/v4/tool/Alternative.java
@@ -31,6 +31,10 @@ package org.antlr.v4.tool;
 
 
 import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.AltAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.TerminalAST;
 import org.stringtemplate.v4.misc.MultiMap;
 
 import java.util.ArrayList;
diff --git a/tool/src/org/antlr/v4/tool/AttributeDict.java b/tool/src/org/antlr/v4/tool/AttributeDict.java
index 4621f6322..b2a1891ab 100644
--- a/tool/src/org/antlr/v4/tool/AttributeDict.java
+++ b/tool/src/org/antlr/v4/tool/AttributeDict.java
@@ -29,7 +29,12 @@
 
 package org.antlr.v4.tool;
 
-import java.util.*;
+import org.antlr.v4.tool.ast.GrammarAST;
+
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Set;
 
 /** Track the attributes within retval, arg lists etc...
  *
diff --git a/tool/src/org/antlr/v4/tool/AttributeResolver.java b/tool/src/org/antlr/v4/tool/AttributeResolver.java
index aae69500d..746a972d5 100644
--- a/tool/src/org/antlr/v4/tool/AttributeResolver.java
+++ b/tool/src/org/antlr/v4/tool/AttributeResolver.java
@@ -29,6 +29,8 @@
 
 package org.antlr.v4.tool;
 
+import org.antlr.v4.tool.ast.ActionAST;
+
 /** Grammars, rules, and alternatives all have symbols visible to
  *  actions.  To evaluate attr exprs, ask action for its resolver
  *  then ask resolver to look up various symbols. Depending on the context,
diff --git a/tool/src/org/antlr/v4/tool/Grammar.java b/tool/src/org/antlr/v4/tool/Grammar.java
index c7ac4411a..396eeee14 100644
--- a/tool/src/org/antlr/v4/tool/Grammar.java
+++ b/tool/src/org/antlr/v4/tool/Grammar.java
@@ -29,16 +29,26 @@
 
 package org.antlr.v4.tool;
 
-import org.antlr.runtime.tree.*;
+import org.antlr.runtime.tree.TreeVisitor;
+import org.antlr.runtime.tree.TreeVisitorAction;
+import org.antlr.runtime.tree.TreeWizard;
 import org.antlr.v4.Tool;
-import org.antlr.v4.misc.*;
-import org.antlr.v4.parse.*;
-import org.antlr.v4.runtime.*;
+import org.antlr.v4.misc.CharSupport;
+import org.antlr.v4.misc.OrderedHashMap;
+import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.parse.GrammarASTAdaptor;
+import org.antlr.v4.parse.GrammarTreeVisitor;
+import org.antlr.v4.parse.TokenVocabParser;
+import org.antlr.v4.runtime.Lexer;
+import org.antlr.v4.runtime.Token;
 import org.antlr.v4.runtime.atn.ATN;
 import org.antlr.v4.runtime.dfa.DFA;
-import org.antlr.v4.runtime.misc.*;
+import org.antlr.v4.runtime.misc.IntSet;
+import org.antlr.v4.runtime.misc.IntervalSet;
+import org.antlr.v4.tool.ast.*;
 
-import java.io.*;
+import java.io.File;
+import java.io.IOException;
 import java.util.*;
 
 public class Grammar implements AttributeResolver {
@@ -233,7 +243,7 @@ public class Grammar implements AttributeResolver {
 				continue;
 			}
 			// did it come back as error node or missing?
-			if ( grammarAST==null || grammarAST instanceof GrammarASTErrorNode ) return;
+			if ( grammarAST==null || grammarAST instanceof GrammarASTErrorNode) return;
 			GrammarRootAST ast = (GrammarRootAST)grammarAST;
 			Grammar g = tool.createGrammar(ast);
 			File f = tool.getImportedGrammarFile(this, importedGrammarName+".g");
@@ -665,14 +675,10 @@ public class Grammar implements AttributeResolver {
         }
 	}
 
-	public String getOption(String key) {
-		if ( ast.options==null ) return null;
-		return ast.options.get(key);
-	}
+	public String getOption(String key) { return ast.getOption(key); }
 
 	public String getOption(String key, String defaultValue) {
-		if ( ast.options==null ) return defaultValue;
-		String v = ast.options.get(key);
+		String v = ast.getOption(key);
 		if ( v!=null ) return v;
 		return defaultValue;
 	}
diff --git a/tool/src/org/antlr/v4/tool/GrammarTransformPipeline.java b/tool/src/org/antlr/v4/tool/GrammarTransformPipeline.java
index 1669773cd..83d567cfa 100644
--- a/tool/src/org/antlr/v4/tool/GrammarTransformPipeline.java
+++ b/tool/src/org/antlr/v4/tool/GrammarTransformPipeline.java
@@ -31,9 +31,12 @@ package org.antlr.v4.tool;
 
 import org.antlr.runtime.*;
 import org.antlr.runtime.misc.DoubleKeyMap;
-import org.antlr.runtime.tree.*;
+import org.antlr.runtime.tree.Tree;
+import org.antlr.runtime.tree.TreeVisitor;
+import org.antlr.runtime.tree.TreeVisitorAction;
 import org.antlr.v4.Tool;
 import org.antlr.v4.parse.*;
+import org.antlr.v4.tool.ast.*;
 
 import java.util.*;
 
diff --git a/tool/src/org/antlr/v4/tool/LabelElementPair.java b/tool/src/org/antlr/v4/tool/LabelElementPair.java
index d20f42f27..0260faa17 100644
--- a/tool/src/org/antlr/v4/tool/LabelElementPair.java
+++ b/tool/src/org/antlr/v4/tool/LabelElementPair.java
@@ -31,6 +31,7 @@ package org.antlr.v4.tool;
 
 import org.antlr.runtime.BitSet;
 import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.tool.ast.GrammarAST;
 
 public class LabelElementPair {
     public static final BitSet tokenTypeForTokens = new BitSet();
diff --git a/tool/src/org/antlr/v4/tool/LexerGrammar.java b/tool/src/org/antlr/v4/tool/LexerGrammar.java
index cbcef8b1c..45cfcd0d0 100644
--- a/tool/src/org/antlr/v4/tool/LexerGrammar.java
+++ b/tool/src/org/antlr/v4/tool/LexerGrammar.java
@@ -31,6 +31,7 @@ package org.antlr.v4.tool;
 
 import org.antlr.runtime.RecognitionException;
 import org.antlr.v4.Tool;
+import org.antlr.v4.tool.ast.GrammarRootAST;
 import org.stringtemplate.v4.misc.MultiMap;
 
 /** */
diff --git a/tool/src/org/antlr/v4/tool/Rule.java b/tool/src/org/antlr/v4/tool/Rule.java
index 7437ab6c2..984edc378 100644
--- a/tool/src/org/antlr/v4/tool/Rule.java
+++ b/tool/src/org/antlr/v4/tool/Rule.java
@@ -29,6 +29,10 @@
 
 package org.antlr.v4.tool;
 
+import org.antlr.v4.tool.ast.ActionAST;
+import org.antlr.v4.tool.ast.GrammarAST;
+import org.antlr.v4.tool.ast.PredAST;
+import org.antlr.v4.tool.ast.RuleAST;
 import org.stringtemplate.v4.misc.MultiMap;
 
 import java.util.*;
diff --git a/tool/src/org/antlr/v4/tool/ActionAST.java b/tool/src/org/antlr/v4/tool/ast/ActionAST.java
similarity index 96%
rename from tool/src/org/antlr/v4/tool/ActionAST.java
rename to tool/src/org/antlr/v4/tool/ast/ActionAST.java
index 98fd55b91..58c322e6d 100644
--- a/tool/src/org/antlr/v4/tool/ActionAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/ActionAST.java
@@ -27,10 +27,11 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.Tree;
+import org.antlr.v4.tool.AttributeResolver;
 
 import java.util.List;
 
diff --git a/tool/src/org/antlr/v4/tool/AltAST.java b/tool/src/org/antlr/v4/tool/ast/AltAST.java
similarity index 97%
rename from tool/src/org/antlr/v4/tool/AltAST.java
rename to tool/src/org/antlr/v4/tool/ast/AltAST.java
index 6940c4a9f..f3a6ddbad 100644
--- a/tool/src/org/antlr/v4/tool/AltAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/AltAST.java
@@ -27,11 +27,12 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.Tree;
 import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.tool.Alternative;
 
 /** Any ALT (which can be child of ALT_REWRITE node) */
 public class AltAST extends GrammarAST {
diff --git a/tool/src/org/antlr/v4/tool/BlockAST.java b/tool/src/org/antlr/v4/tool/ast/BlockAST.java
similarity index 96%
rename from tool/src/org/antlr/v4/tool/BlockAST.java
rename to tool/src/org/antlr/v4/tool/ast/BlockAST.java
index 46e78249e..d3020a439 100644
--- a/tool/src/org/antlr/v4/tool/BlockAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/BlockAST.java
@@ -27,12 +27,13 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.Tree;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 public class BlockAST extends GrammarASTWithOptions {
     // TODO: maybe I need a Subrule object like Rule so these options mov to that?
diff --git a/tool/src/org/antlr/v4/tool/DownAST.java b/tool/src/org/antlr/v4/tool/ast/DownAST.java
similarity index 98%
rename from tool/src/org/antlr/v4/tool/DownAST.java
rename to tool/src/org/antlr/v4/tool/ast/DownAST.java
index 926edf652..c1c228134 100644
--- a/tool/src/org/antlr/v4/tool/DownAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/DownAST.java
@@ -27,7 +27,7 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 
diff --git a/tool/src/org/antlr/v4/tool/GrammarAST.java b/tool/src/org/antlr/v4/tool/ast/GrammarAST.java
similarity index 93%
rename from tool/src/org/antlr/v4/tool/GrammarAST.java
rename to tool/src/org/antlr/v4/tool/ast/GrammarAST.java
index 872453326..5d36afcf9 100644
--- a/tool/src/org/antlr/v4/tool/GrammarAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/GrammarAST.java
@@ -27,15 +27,23 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
-import org.antlr.runtime.*;
-import org.antlr.runtime.tree.*;
-import org.antlr.v4.parse.*;
+import org.antlr.runtime.CharStream;
+import org.antlr.runtime.CommonToken;
+import org.antlr.runtime.Token;
+import org.antlr.runtime.tree.CommonTree;
+import org.antlr.runtime.tree.CommonTreeNodeStream;
+import org.antlr.runtime.tree.Tree;
+import org.antlr.v4.parse.ANTLRParser;
+import org.antlr.v4.parse.GrammarASTAdaptor;
 import org.antlr.v4.runtime.atn.ATNState;
 import org.antlr.v4.runtime.misc.IntervalSet;
+import org.antlr.v4.tool.Grammar;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
 
 public class GrammarAST extends CommonTree {
 	/** For error msgs, nice to know which grammar this AST lives in */
diff --git a/tool/src/org/antlr/v4/tool/GrammarASTErrorNode.java b/tool/src/org/antlr/v4/tool/ast/GrammarASTErrorNode.java
similarity index 95%
rename from tool/src/org/antlr/v4/tool/GrammarASTErrorNode.java
rename to tool/src/org/antlr/v4/tool/ast/GrammarASTErrorNode.java
index 3e0b95984..434d3a2fb 100644
--- a/tool/src/org/antlr/v4/tool/GrammarASTErrorNode.java
+++ b/tool/src/org/antlr/v4/tool/ast/GrammarASTErrorNode.java
@@ -27,9 +27,10 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
-import org.antlr.runtime.*;
+import org.antlr.runtime.Token;
+import org.antlr.runtime.TokenStream;
 import org.antlr.runtime.tree.CommonErrorNode;
 
 /** A node representing erroneous token range in token stream */
diff --git a/tool/src/org/antlr/v4/tool/ast/GrammarASTVisitor.java b/tool/src/org/antlr/v4/tool/ast/GrammarASTVisitor.java
new file mode 100644
index 000000000..a363c61f6
--- /dev/null
+++ b/tool/src/org/antlr/v4/tool/ast/GrammarASTVisitor.java
@@ -0,0 +1,11 @@
+package org.antlr.v4.tool.ast;
+
+/*
+GrammarAST t = ...;
+SynDiagVisitor v = new ...;
+t.visit(v);
+*/
+public interface GrammarASTVisitor {
+	Object visit(RuleAST node);
+	Object visit(AltAST node);
+}
diff --git a/tool/src/org/antlr/v4/tool/GrammarASTWithOptions.java b/tool/src/org/antlr/v4/tool/ast/GrammarASTWithOptions.java
similarity index 93%
rename from tool/src/org/antlr/v4/tool/GrammarASTWithOptions.java
rename to tool/src/org/antlr/v4/tool/ast/GrammarASTWithOptions.java
index 5627883fc..623146416 100644
--- a/tool/src/org/antlr/v4/tool/GrammarASTWithOptions.java
+++ b/tool/src/org/antlr/v4/tool/ast/GrammarASTWithOptions.java
@@ -27,11 +27,12 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 public class GrammarASTWithOptions extends GrammarAST {
     protected Map<String, String> options;
@@ -56,5 +57,9 @@ public class GrammarASTWithOptions extends GrammarAST {
         return options.get(key);
     }
 
+	public int getNumberOfOptions() {
+		return options==null ? 0 : options.size();
+	}
+
     public Map<String, String> getOptions() { return options; }
 }
diff --git a/tool/src/org/antlr/v4/tool/GrammarRootAST.java b/tool/src/org/antlr/v4/tool/ast/GrammarRootAST.java
similarity index 94%
rename from tool/src/org/antlr/v4/tool/GrammarRootAST.java
rename to tool/src/org/antlr/v4/tool/ast/GrammarRootAST.java
index c36367823..94a1799fb 100644
--- a/tool/src/org/antlr/v4/tool/GrammarRootAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/GrammarRootAST.java
@@ -27,12 +27,14 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
-import org.antlr.runtime.*;
+import org.antlr.runtime.Token;
+import org.antlr.runtime.TokenStream;
 import org.antlr.runtime.tree.Tree;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Map;
 
 public class GrammarRootAST extends GrammarASTWithOptions {
     public static final Map defaultOptions =
diff --git a/tool/src/org/antlr/v4/tool/PredAST.java b/tool/src/org/antlr/v4/tool/ast/PredAST.java
similarity index 98%
rename from tool/src/org/antlr/v4/tool/PredAST.java
rename to tool/src/org/antlr/v4/tool/ast/PredAST.java
index 80761b669..672e7e3be 100644
--- a/tool/src/org/antlr/v4/tool/PredAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/PredAST.java
@@ -27,7 +27,7 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 
diff --git a/tool/src/org/antlr/v4/tool/RuleAST.java b/tool/src/org/antlr/v4/tool/ast/RuleAST.java
similarity index 95%
rename from tool/src/org/antlr/v4/tool/RuleAST.java
rename to tool/src/org/antlr/v4/tool/ast/RuleAST.java
index fc18c9448..86e9607c6 100644
--- a/tool/src/org/antlr/v4/tool/RuleAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/RuleAST.java
@@ -27,13 +27,15 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.Tree;
 import org.antlr.v4.parse.ANTLRParser;
 
 public class RuleAST extends GrammarASTWithOptions {
+
+
 	public RuleAST(GrammarAST node) {
 		super(node);
 	}
@@ -55,4 +57,6 @@ public class RuleAST extends GrammarASTWithOptions {
 		}
 		return null;
 	}
+
+	public Object visit(GrammarASTVisitor v) { return v.visit(this); }
 }
diff --git a/tool/src/org/antlr/v4/tool/TerminalAST.java b/tool/src/org/antlr/v4/tool/ast/TerminalAST.java
similarity index 98%
rename from tool/src/org/antlr/v4/tool/TerminalAST.java
rename to tool/src/org/antlr/v4/tool/ast/TerminalAST.java
index dbe0879c2..0c382ed86 100644
--- a/tool/src/org/antlr/v4/tool/TerminalAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/TerminalAST.java
@@ -27,7 +27,7 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.tree.Tree;
diff --git a/tool/src/org/antlr/v4/tool/TreePatternAST.java b/tool/src/org/antlr/v4/tool/ast/TreePatternAST.java
similarity index 98%
rename from tool/src/org/antlr/v4/tool/TreePatternAST.java
rename to tool/src/org/antlr/v4/tool/ast/TreePatternAST.java
index 9a7e3fd28..e256cab31 100644
--- a/tool/src/org/antlr/v4/tool/TreePatternAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/TreePatternAST.java
@@ -27,7 +27,7 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;
 import org.antlr.v4.runtime.atn.ATNState;
diff --git a/tool/src/org/antlr/v4/tool/UpAST.java b/tool/src/org/antlr/v4/tool/ast/UpAST.java
similarity index 98%
rename from tool/src/org/antlr/v4/tool/UpAST.java
rename to tool/src/org/antlr/v4/tool/ast/UpAST.java
index 9d1be30e1..286f90024 100644
--- a/tool/src/org/antlr/v4/tool/UpAST.java
+++ b/tool/src/org/antlr/v4/tool/ast/UpAST.java
@@ -27,7 +27,7 @@
  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package org.antlr.v4.tool;
+package org.antlr.v4.tool.ast;
 
 import org.antlr.runtime.Token;