Extended option 'dc4' to handle inlined class references (mainly Eclipse). See IDEA-135387 for an example.

src/org/jetbrains/java/decompiler/modules/decompiler/SimplifyExprentsHelper.java

@@ -15,24 +15,41 @@
  */
 package org.jetbrains.java.decompiler.modules.decompiler;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Set;
+
 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
 import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;
-import org.jetbrains.java.decompiler.modules.decompiler.exps.*;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.ArrayExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.AssignmentExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.ConstExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.ExitExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.Exprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.FunctionExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.InvocationExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.MonitorExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.NewExprent;
+import org.jetbrains.java.decompiler.modules.decompiler.exps.VarExprent;
 import org.jetbrains.java.decompiler.modules.decompiler.sforms.SSAConstructorSparseEx;
 import org.jetbrains.java.decompiler.modules.decompiler.stats.IfStatement;
 import org.jetbrains.java.decompiler.modules.decompiler.stats.Statement;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPair;
 import org.jetbrains.java.decompiler.struct.StructClass;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
 import org.jetbrains.java.decompiler.util.FastSparseSetFactory.FastSparseSet;
 
-import java.util.*;
-import java.util.Map.Entry;
-
 public class SimplifyExprentsHelper {
 
+  static MatchEngine class14Builder = new MatchEngine();
+  
   private boolean firstInvocation;
 
   public SimplifyExprentsHelper(boolean firstInvocation) {
@@ -45,6 +62,8 @@ public class SimplifyExprentsHelper {
 
     if (stat.getExprents() == null) {
 
+      boolean processClass14 = DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_CLASS_1_4);
+
       while (true) {
 
         boolean changed = false;
@@ -61,6 +80,11 @@ public class SimplifyExprentsHelper {
           if (changed = buildIff(st, ssa)) {
             break;
           }
+
+          // collapse inlined .class property in version 1.4 and before
+          if (processClass14 && (changed = collapseInlinedClass14(st))) {
+            break;
+          }
         }
 
         res |= changed;
@@ -852,4 +876,53 @@ public class SimplifyExprentsHelper {
 
     return false;
   }
+
+  static {
+    class14Builder.parse(
+          "statement type:if iftype:if exprsize:-1\n" +
+          " exprent position:head type:if\n" +
+          "  exprent type:function functype:eq\n" +
+          "   exprent type:field name:$field$\n" +
+          "   exprent type:constant consttype:null\n" +
+          " statement type:basicblock\n" +
+          "  exprent position:-1 type:assignment ret:$assignfield$\n" +
+          "   exprent type:var index:$var$\n" +
+          "   exprent type:field name:$field$\n" +
+          " statement type:sequence statsize:2\n" +
+          "  statement type:trycatch\n" +  
+          "   statement type:basicblock exprsize:1\n" +
+          "    exprent type:assignment\n" +
+          "     exprent type:var index:$var$\n" +
+          "     exprent type:invocation invclass:java/lang/Class signature:forName(Ljava/lang/String;)Ljava/lang/Class;\n" +
+          "      exprent position:0 type:constant consttype:string constvalue:$classname$\n" +
+          "   statement type:basicblock exprsize:1\n" +
+          "    exprent type:exit exittype:throw\n" + 
+          "  statement type:basicblock exprsize:1\n" + 
+          "   exprent type:assignment\n" + 
+          "    exprent type:field name:$field$\n" +
+          "    exprent type:var index:$var$"
+        );
+  }
+  
+  private static boolean collapseInlinedClass14(Statement stat) {
+
+    boolean ret = class14Builder.match(stat);
+    if(ret) {
+      
+      String class_name = (String)class14Builder.getVariableValue("$classname$");
+      AssignmentExprent assfirst = (AssignmentExprent)class14Builder.getVariableValue("$assignfield$");
+
+      assfirst.replaceExprent(assfirst.getRight(), new ConstExprent(VarType.VARTYPE_CLASS, class_name, null));
+      
+      List<Exprent> data = new ArrayList<Exprent>();
+      data.addAll(stat.getFirst().getExprents());
+
+      stat.setExprents(data);
+
+      SequenceHelper.destroyAndFlattenStatement(stat);
+    }
+    
+    return ret;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/ConstExprent.java

@@ -23,9 +23,14 @@ import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.struct.gen.FieldDescriptor;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 
 import java.util.*;
+import java.util.Map.Entry;
 
 public class ConstExprent extends Exprent {
   private static final Map<Integer, String> ESCAPES = new HashMap<Integer, String>() {{
@@ -395,4 +400,37 @@ public class ConstExprent extends Exprent {
   public boolean isBoolPermitted() {
     return boolPermitted;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    for(Entry<MatchProperties, RuleValue> rule : matchNode.getRules().entrySet()) {
+      RuleValue rule_value = rule.getValue();
+      
+      switch(rule.getKey()) {
+      case EXPRENT_CONSTTYPE:
+        if(!rule_value.value.equals(this.constType)) {
+          return false;
+        }
+        break;
+      case EXPRENT_CONSTVALUE:
+        if(rule_value.isVariable()) {
+          if(!engine.checkAndSetVariableValue(rule_value.value.toString(), this.value)) {
+            return false;
+          }
+        } 
+        break;
+      }
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/ExitExprent.java

@@ -25,11 +25,15 @@ import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.struct.attr.StructExceptionsAttribute;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.Map.Entry;
 
 public class ExitExprent extends Exprent {
 
@@ -151,4 +155,25 @@ public class ExitExprent extends Exprent {
   public VarType getRetType() {
     return retType;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    Integer type = (Integer)matchNode.getRuleValue(MatchProperties.EXPRENT_EXITTYPE);
+    if(type != null) {
+      if(this.exitType != type.intValue()) {
+        return false;
+      }
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/Exprent.java

@@ -15,6 +15,13 @@
  */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Set;
+
 import org.jetbrains.java.decompiler.main.DecompilerContext;
 import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
@@ -22,10 +29,12 @@ import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPair;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.IMatchable;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 
-import java.util.*;
-
-public class Exprent {
+public class Exprent implements IMatchable {
 
   public static final int MULTIPLE_USES = 1;
   public static final int SIDE_EFFECTS_FREE = 2;
@@ -131,4 +140,58 @@ public class Exprent {
       }
     }
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public IMatchable findObject(MatchNode matchNode, int index) {
+    
+    if(matchNode.getType() != MatchNode.MATCHNODE_EXPRENT) {
+      return null;
+    }
+
+    List<Exprent> lstAllExprents = getAllExprents();
+    
+    if(lstAllExprents == null || lstAllExprents.isEmpty()) {
+      return null;
+    }
+    
+    String position = (String)matchNode.getRuleValue(MatchProperties.EXPRENT_POSITION);
+    if(position != null) {
+      if(position.matches("-?\\d+")) {
+        return lstAllExprents.get((lstAllExprents.size() + Integer.parseInt(position)) % lstAllExprents.size()); // care for negative positions
+      }
+    } else if(index < lstAllExprents.size()) { // use 'index' parameter
+      return lstAllExprents.get(index);
+    }
+
+    return null;
+  }
+
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+    
+    if(matchNode.getType() != MatchNode.MATCHNODE_EXPRENT) {
+      return false;
+    }
+    
+    for(Entry<MatchProperties, RuleValue> rule : matchNode.getRules().entrySet()) {
+      switch(rule.getKey()) {
+      case EXPRENT_TYPE:
+        if(this.type != ((Integer)rule.getValue().value).intValue()) {
+          return false;
+        }
+        break;
+      case EXPRENT_RET:
+        if(!engine.checkAndSetVariableValue((String)rule.getValue().value, this)) {
+          return false;
+        }
+        break;
+      }
+      
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/FieldExprent.java

@@ -26,6 +26,10 @@ import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPair;
 import org.jetbrains.java.decompiler.struct.consts.LinkConstant;
 import org.jetbrains.java.decompiler.struct.gen.FieldDescriptor;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 import org.jetbrains.java.decompiler.util.TextUtil;
 
@@ -181,4 +185,31 @@ public class FieldExprent extends Exprent {
   public String getName() {
     return name;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    RuleValue rule = matchNode.getRules().get(MatchProperties.EXPRENT_FIELD_NAME);
+    if(rule != null) {
+      if(rule.isVariable()) {
+        if(!engine.checkAndSetVariableValue((String)rule.value, this.name)) {
+          return false;
+        }
+      } else { 
+        if(!rule.value.equals(this.name)) {
+          return false;
+        }
+      }
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/FunctionExprent.java

@@ -21,10 +21,15 @@ import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.IMatchable;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 import org.jetbrains.java.decompiler.util.ListStack;
 
 import java.util.*;
+import java.util.Map.Entry;
 
 public class FunctionExprent extends Exprent {
 
@@ -604,4 +609,25 @@ public class FunctionExprent extends Exprent {
   public void setImplicitType(VarType implicitType) {
     this.implicitType = implicitType;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    Integer type = (Integer)matchNode.getRuleValue(MatchProperties.EXPRENT_FUNCTYPE);
+    if(type != null) {
+      if(this.funcType != type.intValue()) {
+        return false;
+      }
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java

@@ -15,6 +15,13 @@
  */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;
 
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Set;
+
 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
@@ -31,12 +38,13 @@ import org.jetbrains.java.decompiler.struct.StructMethod;
 import org.jetbrains.java.decompiler.struct.consts.LinkConstant;
 import org.jetbrains.java.decompiler.struct.gen.MethodDescriptor;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 import org.jetbrains.java.decompiler.util.ListStack;
 import org.jetbrains.java.decompiler.util.TextUtil;
 
-import java.util.*;
-
 public class InvocationExprent extends Exprent {
 
   public static final int INVOKE_SPECIAL = 1;
@@ -87,6 +95,7 @@ public class InvocationExprent extends Exprent {
         break;
       case CodeConstants.opc_invokedynamic:
         invocationTyp = INVOKE_DYNAMIC;
+
         classname = "java/lang/Class"; // dummy class name
         invokeDynamicClassSuffix = "##Lambda_" + cn.index1 + "_" + cn.index2;
     }
@@ -482,4 +491,47 @@ public class InvocationExprent extends Exprent {
   public String getInvokeDynamicClassSuffix() {
     return invokeDynamicClassSuffix;
   }
+
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    for(Entry<MatchProperties, RuleValue> rule : matchNode.getRules().entrySet()) {
+      RuleValue value = rule.getValue();
+      
+      switch(rule.getKey()) {
+      case EXPRENT_INVOCATION_PARAMETER:
+        if(value.isVariable()) {
+          if(value.parameter < lstParameters.size()) {
+            if(!engine.checkAndSetVariableValue(value.value.toString(), lstParameters.get(value.parameter))) {
+              return false;
+            }
+          } else {
+            return false;
+          }
+        }
+        break;
+      case EXPRENT_INVOCATION_CLASS:
+        if(!value.value.equals(this.classname)) {
+          return false;
+        }
+        break;
+      case EXPRENT_INVOCATION_SIGNATURE:
+        if(!value.value.equals(this.name + this.stringDescriptor)) {
+          return false;
+        }
+        break;
+      }
+      
+    }
+    
+    return true;
+  }
+
 }

src/org/jetbrains/java/decompiler/modules/decompiler/exps/VarExprent.java

@@ -26,6 +26,10 @@ import org.jetbrains.java.decompiler.modules.decompiler.vars.VarProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.VarTypeProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPair;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 
 import java.util.ArrayList;
@@ -180,4 +184,31 @@ public class VarExprent extends Exprent {
   public void setStack(boolean stack) {
     this.stack = stack;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+    
+    RuleValue rule = matchNode.getRules().get(MatchProperties.EXPRENT_VAR_INDEX);
+    if(rule != null) {
+      if(rule.isVariable()) {
+        if(!engine.checkAndSetVariableValue((String)rule.value, this.index)) {
+          return false;
+        }
+      } else { 
+        if(this.index != Integer.valueOf((String)rule.value).intValue()) {
+          return false;
+        }
+      }
+    }
+    
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/stats/IfStatement.java

@@ -22,10 +22,15 @@ import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.StatEdge;
 import org.jetbrains.java.decompiler.modules.decompiler.exps.Exprent;
 import org.jetbrains.java.decompiler.modules.decompiler.exps.IfExprent;
+import org.jetbrains.java.decompiler.struct.match.IMatchable;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.IMatchable.MatchProperties;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map.Entry;
 
 
 public class IfStatement extends Statement {
@@ -421,4 +426,42 @@ public class IfStatement extends Statement {
   public StatEdge getElseEdge() {
     return elseedge;
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public IMatchable findObject(MatchNode matchNode, int index) {
+
+    IMatchable object = super.findObject(matchNode, index);
+    if(object != null) {
+      return object;
+    }
+    
+    if(matchNode.getType() == MatchNode.MATCHNODE_EXPRENT) {
+      String position = (String)matchNode.getRuleValue(MatchProperties.EXPRENT_POSITION);
+      if("head".equals(position)) {
+        return getHeadexprent();
+      }
+    }
+
+    return null;
+  }
+
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+
+    if(!super.match(matchNode, engine)) {
+      return false;
+    }
+
+    Integer type = (Integer)matchNode.getRuleValue(MatchProperties.STATEMENT_IFTYPE);
+    if(type != null) {
+      if(this.iftype != type.intValue()) {
+        return false;
+      }
+    }
+        
+    return true;
+  }
+  
 }

src/org/jetbrains/java/decompiler/modules/decompiler/stats/Statement.java

@@ -15,6 +15,15 @@
  */
 package org.jetbrains.java.decompiler.modules.decompiler.stats;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.code.InstructionSequence;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
@@ -24,11 +33,13 @@ import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.StatEdge;
 import org.jetbrains.java.decompiler.modules.decompiler.StrongConnectivityHelper;
 import org.jetbrains.java.decompiler.modules.decompiler.exps.Exprent;
+import org.jetbrains.java.decompiler.struct.match.IMatchable;
+import org.jetbrains.java.decompiler.struct.match.MatchEngine;
+import org.jetbrains.java.decompiler.struct.match.MatchNode;
+import org.jetbrains.java.decompiler.struct.match.MatchNode.RuleValue;
 import org.jetbrains.java.decompiler.util.VBStyleCollection;
 
-import java.util.*;
-
-public class Statement {
+public class Statement implements IMatchable {
 
   public static final int STATEDGE_ALL = 1 << 31;
   public static final int STATEDGE_DIRECT_ALL = 1 << 30;
@@ -859,4 +870,78 @@ public class Statement {
   public String toString() {
     return id.toString();
   }
+  
+  // *****************************************************************************
+  // IMatchable implementation
+  // *****************************************************************************
+  
+  public IMatchable findObject(MatchNode matchNode, int index) {
+    
+    int node_type = matchNode.getType();
+    
+    if(node_type == MatchNode.MATCHNODE_STATEMENT) {
+      String position = (String)matchNode.getRuleValue(MatchProperties.STATEMENT_POSITION);
+      if(position != null) {
+        if(position.matches("-?\\d+")) {
+          return this.stats.get((this.stats.size() + Integer.parseInt(position)) % this.stats.size()); // care for negative positions
+        }
+      } else if(index < this.stats.size()) { // use 'index' parameter
+        return this.stats.get(index);
+      }
+    } else if(node_type == MatchNode.MATCHNODE_EXPRENT && this.exprents != null) {
+      String position = (String)matchNode.getRuleValue(MatchProperties.EXPRENT_POSITION);
+      if(position != null) {
+        if(position.matches("-?\\d+")) {
+          return this.exprents.get((this.exprents.size() + Integer.parseInt(position)) % this.exprents.size()); // care for negative positions
+        }
+      } else if(index < this.exprents.size()) { // use 'index' parameter
+        return this.exprents.get(index);
+      }
+    }
+
+    return null;
+  }
+
+  public boolean match(MatchNode matchNode, MatchEngine engine) {
+    
+    if(matchNode.getType() != MatchNode.MATCHNODE_STATEMENT) {
+      return false;
+    }
+    
+    for(Entry<MatchProperties, RuleValue> rule : matchNode.getRules().entrySet()) {
+      switch(rule.getKey()) {
+      case STATEMENT_TYPE:
+        if(this.type != ((Integer)rule.getValue().value).intValue()) {
+          return false;
+        }
+        break;
+      case STATEMENT_STATSIZE:
+        if(this.stats.size() != ((Integer)rule.getValue().value).intValue()) {
+          return false;
+        }
+        break;
+      case STATEMENT_EXPRSIZE:
+        int exprsize = ((Integer)rule.getValue().value).intValue();
+        if(exprsize == -1) {
+          if(this.exprents != null) {
+            return false;
+          }
+        } else {
+          if(this.exprents == null || this.exprents.size() != exprsize) {
+            return false;
+          }
+        }
+        break;
+      case STATEMENT_RET:
+        if(!engine.checkAndSetVariableValue((String)rule.getValue().value, this)) {
+          return false;
+        }
+        break;
+      }
+      
+    }
+    
+    return true;
+  }
+  
 }