From b9f8bac585fa65924ec54505c352ac5661c3dce7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Westk=C3=A4mper?= <timo.westkamper@mysema.com>
Date: Wed, 25 Nov 2009 10:18:26 +0000
Subject: [PATCH] refactored Path implementations to use PathMixin as a
 delegate

---
 .../com/mysema/query/types/expr/EArray.java   |  5 +
 .../com/mysema/query/types/path/PArray.java   | 69 ++++++-------
 .../com/mysema/query/types/path/PBoolean.java | 90 ++++++++---------
 .../mysema/query/types/path/PCollection.java  | 51 ++++------
 .../mysema/query/types/path/PComparable.java  | 65 +++++--------
 .../com/mysema/query/types/path/PDate.java    | 55 ++++-------
 .../mysema/query/types/path/PDateTime.java    | 85 +++++++---------
 .../com/mysema/query/types/path/PEntity.java  | 96 +++++++++----------
 .../com/mysema/query/types/path/PList.java    | 41 ++++----
 .../com/mysema/query/types/path/PMap.java     | 93 ++++++++----------
 .../com/mysema/query/types/path/PNumber.java  | 93 ++++++++----------
 .../com/mysema/query/types/path/PSet.java     | 57 +++++------
 .../com/mysema/query/types/path/PSimple.java  | 94 ++++++++----------
 .../com/mysema/query/types/path/PString.java  | 90 ++++++++---------
 .../com/mysema/query/types/path/PTime.java    | 58 +++++------
 .../com/mysema/query/types/path/Path.java     | 12 +--
 .../mysema/query/types/path/PathInits.java    |  4 +-
 .../mysema/query/types/path/PathMetadata.java | 12 +--
 .../mysema/query/types/path/PathMixin.java    | 84 ++++++++++++++++
 19 files changed, 532 insertions(+), 622 deletions(-)
 create mode 100644 querydsl-core/src/main/java/com/mysema/query/types/path/PathMixin.java

diff --git a/querydsl-core/src/main/java/com/mysema/query/types/expr/EArray.java b/querydsl-core/src/main/java/com/mysema/query/types/expr/EArray.java
index da7b57800..debe9787c 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/expr/EArray.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/expr/EArray.java
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) 2009 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
 package com.mysema.query.types.expr;
 
 import javax.annotation.Nonnegative;
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PArray.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PArray.java
index 9c42ed070..b90c64d73 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PArray.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PArray.java
@@ -14,7 +14,6 @@ import com.mysema.query.types.expr.EArray;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ENumber;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
 import com.mysema.query.types.operation.ONumber;
 import com.mysema.query.types.operation.Ops;
 
@@ -32,31 +31,31 @@ public class PArray<E> extends Expr<E[]> implements Path<E[]>, EArray<E>{
     
     private final Class<E> componentType;
     
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
+    private final Path<E[]> pathMixin;
     
     private volatile ENumber<Integer> size;
-    
-    private final Path<?> root;
 
     @SuppressWarnings("unchecked")
     public PArray(Class<? super E> type, PathMetadata<?> metadata) {
         super((Class)Object[].class);
+        this.pathMixin = new PathMixin<E[]>(this, metadata);
         this.arrayType = (Class<E[]>) Array.newInstance(type, 0).getClass();
         this.componentType = (Class<E>) type;
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
     }
 
-//    public PArray(Class<E> type, @NotEmpty String var) {
-//        this(type, PathMetadata.forVariable(var));
-//    }
+    @Override
+    public void accept(Visitor v) {
+        v.visit(this);        
+    }
 
-    @SuppressWarnings("unchecked")
+    @Override
+    public Expr<E[]> asExpr() {
+        return this;
+    }
+
+@Override
     public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
+        return pathMixin.equals(o);
     }
 
     /**
@@ -70,6 +69,7 @@ public class PArray<E> extends Expr<E[]> implements Path<E[]>, EArray<E>{
         return new PSimple<E>(componentType, md);
     }
 
+
     /**
      * Create a expression for indexed access
      * 
@@ -81,21 +81,21 @@ public class PArray<E> extends Expr<E[]> implements Path<E[]>, EArray<E>{
         return new PSimple<E>(componentType, md);   
     }
 
-//    @Override
+    //    @Override
     public Class<E> getElementType() {
         return componentType;
     }
 
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
+        return pathMixin.getMetadata();
+    }    
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
-
+    
     @Override
     public Class<E[]> getType() {
         return arrayType;
@@ -103,25 +103,19 @@ public class PArray<E> extends Expr<E[]> implements Path<E[]>, EArray<E>{
 
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
+        return pathMixin.isNotNull();
     }
 
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
+    
     /**
      * Create an expression for the array size
      * 
@@ -133,14 +127,5 @@ public class PArray<E> extends Expr<E[]> implements Path<E[]>, EArray<E>{
         }
         return size;
     }
-
-    @Override
-    public void accept(Visitor v) {
-        v.visit(this);        
-    }
-
-    @Override
-    public Expr<E[]> asExpr() {
-        return this;
-    }
+    
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PBoolean.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PBoolean.java
index e4f2c4976..d7bfdde28 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PBoolean.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PBoolean.java
@@ -7,8 +7,6 @@ package com.mysema.query.types.path;
 
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -20,71 +18,59 @@ import com.mysema.query.util.NotEmpty;
  */
 @SuppressWarnings("serial")
 public class PBoolean extends EBoolean implements Path<Boolean> {
-    
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
 
-    public PBoolean(PathMetadata<?> metadata) {
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
+    private final Path<Boolean> pathMixin;
 
-    public PBoolean(@NotEmpty String var) {
-        this(PathMetadata.forVariable(var));
-    }
-    
     public PBoolean(Path<?> parent, @NotEmpty String property) {
         this(PathMetadata.forProperty(parent, property));
     }
 
-    @SuppressWarnings("unchecked")
-    @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
+    public PBoolean(PathMetadata<?> metadata) {
+        this.pathMixin = new PathMixin<Boolean>(this, metadata);
     }
-
-    @Override
-    public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
-
-    @Override
-    public Path<?> getRoot() {
-        return root;
-    }
-
-    @Override
-    public int hashCode() {
-        return metadata.hashCode();
-    }
-
-    @Override
-    public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+    
+    public PBoolean(@NotEmpty String var) {
+        this(PathMetadata.forVariable(var));
     }
     
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
+    } 
 
     @Override
     public EBoolean asExpr() {
         return this;
     }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return pathMixin.getMetadata();
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
+    }
+
+    @Override
+    public int hashCode() {
+        return pathMixin.hashCode();
+    }
+
+    @Override
+    public EBoolean isNotNull() {
+        return pathMixin.isNotNull();
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
+    
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PCollection.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PCollection.java
index 91abb35cd..90db9e3dd 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PCollection.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PCollection.java
@@ -12,8 +12,6 @@ import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ECollectionBase;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -26,23 +24,18 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings("serial")
 public class PCollection<E> extends ECollectionBase<Collection<E>,E> implements Path<Collection<E>> {
     
-    private final PathMetadata<?> metadata;
-    
     private final Class<E> elementType;
     
     private final String entityName;
     
-    private volatile EBoolean isnull, isnotnull;    
-    
-    private final Path<?> root;
+    private final Path<Collection<E>> pathMixin;
     
     @SuppressWarnings("unchecked")
     public PCollection(Class<? super E> type, @NotEmpty String entityName, PathMetadata<?> metadata) {
-        super((Class)Collection.class);
+        super((Class)Collection.class);        
         this.elementType = (Class<E>) Assert.notNull(type,"type is null");
-        this.metadata = Assert.notNull(metadata,"metadata is null");
         this.entityName = Assert.notNull(entityName,"entityName is null");
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<Collection<E>>(this, metadata);
     }
 
     @Override
@@ -50,17 +43,21 @@ public class PCollection<E> extends ECollectionBase<Collection<E>,E> implements
         v.visit(this);        
     }
 
-    @SuppressWarnings("unchecked")
     @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
+    public Expr<Collection<E>> asExpr() {
+        return this;
     }
 
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
     @Override
     public Class<E> getElementType() {
         return elementType;
     }
-
+    
     /**
      * Get the entity name for this Entity collection path
      * 
@@ -69,42 +66,30 @@ public class PCollection<E> extends ECollectionBase<Collection<E>,E> implements
     public String getEntityName() {
         return entityName;
     }
-
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
-    
+
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-
-    
-    @Override
-    public Expr<Collection<E>> asExpr() {
-        return this;
+        return pathMixin.isNull();
     }
 
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PComparable.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PComparable.java
index 3d7430fb4..8c2c977d1 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PComparable.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PComparable.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.EComparable;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -21,75 +19,64 @@ import com.mysema.query.util.NotEmpty;
  * @see java.util.Comparable
  */
 @SuppressWarnings({"unchecked","serial"})
-public class PComparable<D extends Comparable> extends EComparable<D> implements
-        Path<D> {
-    
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
+public class PComparable<D extends Comparable> extends EComparable<D> implements Path<D> {
 
-    public PComparable(Class<? extends D> type, PathMetadata<?> metadata) {
-        super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
-
-    public PComparable(Class<? extends D> type, @NotEmpty String var) {
-        this(type, PathMetadata.forVariable(var));
-    }
+    private final Path<D> pathMixin;
     
     public PComparable(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
         this(type, PathMetadata.forProperty(parent, property));
     }
+
+    public PComparable(Class<? extends D> type, PathMetadata<?> metadata) {
+        super(type);
+        this.pathMixin = new PathMixin<D>(this, metadata);
+    }
+    
+    public PComparable(Class<? extends D> type, @NotEmpty String var) {
+        this(type, PathMetadata.forVariable(var));
+    }
     
     public PComparable(Path<?> parent, @NotEmpty String property) {
         this((Class<? extends D>) Comparable.class, PathMetadata.forProperty(parent, property));
     }
-
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
-    }
     
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
 
+    @Override
+    public EComparable<D> asExpr() {
+        return this;
+    }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
 
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-    
-    @Override
-    public EComparable<D> asExpr() {
-        return this;
+        return pathMixin.isNull();
     }
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PDate.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PDate.java
index 86fb007ff..62e73e065 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PDate.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PDate.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.EDate;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -20,70 +18,59 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings({"unchecked","serial"})
 public class PDate<D extends Comparable> extends EDate<D> implements Path<D>{
 
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
+    private final Path<D> pathMixin;
     
+    public PDate(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
+        this(type, PathMetadata.forProperty(parent, property));
+    }
+
     public PDate(Class<? extends D> type, PathMetadata<?> metadata) {
         super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<D>(this, metadata);
     }
 
     public PDate(Class<? extends D> type, @NotEmpty String var) {
         this(type, PathMetadata.forVariable(var));
     }
-
-    public PDate(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
-        this(type, PathMetadata.forProperty(parent, property));
-    }
-    
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
-    }
     
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
 
+    @Override
+    public EDate<D> asExpr() {
+        return this;
+    }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
 
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-    
-    @Override
-    public EDate<D> asExpr() {
-        return this;
+        return pathMixin.isNull();
     }
 
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PDateTime.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PDateTime.java
index 32773df9f..91098d3d6 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PDateTime.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PDateTime.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.EDateTime;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -20,69 +18,58 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings({"unchecked","serial"})
 public class PDateTime<D extends Comparable> extends EDateTime<D> implements Path<D> {
 
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
+    private final Path<D> pathMixin;
     
+    public PDateTime(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
+        this(type, PathMetadata.forProperty(parent, property));
+    }
+
     public PDateTime(Class<? extends D> type, PathMetadata<?> metadata) {
         super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<D>(this, metadata);
     }
 
     public PDateTime(Class<? extends D> type, @NotEmpty String var) {
         this(type, PathMetadata.forVariable(var));
     }
 
-    public PDateTime(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
-        this(type, PathMetadata.forProperty(parent, property));
-    }
-
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
-    }
-
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
-    
-    @Override
-    public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
-
-    @Override
-    public Path<?> getRoot() {
-        return root;
-    }
-
-    @Override
-    public int hashCode() {
-        return metadata.hashCode();
-    }
-
-    @Override
-    public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
 
     @Override
     public EDateTime<D> asExpr() {
         return this;
     }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return pathMixin.getMetadata();
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
+    }
+
+    @Override
+    public int hashCode() {
+        return pathMixin.hashCode();
+    }
+
+    @Override
+    public EBoolean isNotNull() {
+        return pathMixin.isNotNull();
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PEntity.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PEntity.java
index e1776d91b..48d5800d9 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PEntity.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PEntity.java
@@ -30,17 +30,12 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
     
     private final String entityName;
     
-    private volatile EBoolean isnull, isnotnull;
+    private final Path<D> pathMixin;
     
-    private final PathMetadata<?> metadata;
-
-    private final Path<?> root;
-
     public PEntity(Class<? extends D> type, @NotEmpty String entityName, PathMetadata<?> metadata) {
         super(type);
+        this.pathMixin = new PathMixin<D>(this, metadata);
         this.entityName = entityName;
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
     }
 
     @Override
@@ -76,6 +71,16 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
         return this;
     }
 
+    /**
+     * @param <A>
+     * @param property
+     * @param type
+     * @return
+     */
+    protected <A> PArray<A> createArray(@NotEmpty String property, Class<? super A> type) {
+        return new PArray<A>(type, PathMetadata.forProperty(this, property));
+    }
+
     /**
      * @param propertyName
      * @return
@@ -84,6 +89,16 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
         return new PBoolean(this, propertyName);
     }
 
+    /**
+     * @param <A>
+     * @param property
+     * @param type
+     * @return
+     */
+    protected <A> PCollection<A> createCollection(@NotEmpty String property, Class<? super A> type) {
+        return new PCollection<A>(type, type.getSimpleName(), PathMetadata.forProperty(this, property));
+    }
+
     /**
      * @param <A>
      * @param property
@@ -94,7 +109,7 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
     protected <A extends Comparable> PComparable<A> createComparable(@NotEmpty String property, Class<? super A> type) {
         return new PComparable<A>((Class)type, this, property);
     }
-
+    
     /**
      * @param <A>
      * @param property
@@ -117,36 +132,6 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
         return new PDateTime<A>((Class)type, this, property);
     }
     
-    /**
-     * @param <A>
-     * @param property
-     * @param type
-     * @return
-     */
-    protected <A> PArray<A> createArray(@NotEmpty String property, Class<? super A> type) {
-        return new PArray<A>(type, PathMetadata.forProperty(this, property));
-    }
-
-    /**
-     * @param <A>
-     * @param property
-     * @param type
-     * @return
-     */
-    protected <A> PCollection<A> createCollection(@NotEmpty String property, Class<? super A> type) {
-        return new PCollection<A>(type, type.getSimpleName(), PathMetadata.forProperty(this, property));
-    }
-    
-    /**
-     * @param <A>
-     * @param property
-     * @param type
-     * @return
-     */
-    protected <A> PSet<A> createSet(@NotEmpty String property, Class<? super A> type) {
-        return new PSet<A>(type, type.getSimpleName(), PathMetadata.forProperty(this, property));
-    }
-
     /**
      * @param <A>
      * @param <E>
@@ -186,6 +171,16 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
         return new PNumber<A>((Class)type, this, property);
     }
 
+    /**
+     * @param <A>
+     * @param property
+     * @param type
+     * @return
+     */
+    protected <A> PSet<A> createSet(@NotEmpty String property, Class<? super A> type) {
+        return new PSet<A>(type, type.getSimpleName(), PathMetadata.forProperty(this, property));
+    }
+
     /**
      * @param <A>
      * @param path
@@ -216,11 +211,12 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
         return new PTime<A>((Class)type, this, property);
     }
 
-    @SuppressWarnings("unchecked")
+
     @Override
     public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
+        return pathMixin.equals(o);
     }
+    
 
     /**
      * Get the entity name for this Entity path
@@ -233,17 +229,17 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
     
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
     
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
-    
+
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     /**
@@ -256,20 +252,14 @@ public class PEntity<D> extends Expr<D> implements Path<D> {
     public <B extends D> EBoolean instanceOf(Class<B> type) {
         return OBoolean.create(Ops.INSTANCE_OF, this, ExprConst.create(type));
     }
-    
+
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
+        return pathMixin.isNull();
     }
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PList.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PList.java
index 3faafd298..da4b7d397 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PList.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PList.java
@@ -19,8 +19,6 @@ import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ECollectionBase;
 import com.mysema.query.types.expr.EList;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -48,24 +46,19 @@ public class PList<E, Q extends Expr<E>> extends ECollectionBase<List<E>,E> impl
     
     protected final String entityName;
     
-    private volatile EBoolean isnull, isnotnull;
+    private final Path<List<E>> pathMixin;
     
-    private final PathMetadata<?> metadata;
-    
-    private final Class<Q> queryType;
+    private final Class<Q> queryType;    
     
     private Constructor<Q> queryTypeConstructor;    
     
-    private final Path<?> root;
-    
     @SuppressWarnings("unchecked")
     public PList(Class<? super E> elementType, @NotEmpty String entityName, Class<Q> queryType, PathMetadata<?> metadata) {
         super((Class)List.class);
         this.elementType = (Class<E>) Assert.notNull(elementType,"type is null");
-        this.metadata = Assert.notNull(metadata,"metadata is null");
         this.entityName = Assert.notNull(entityName,"entityName is null");
         this.queryType = queryType;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<List<E>>(this, metadata);
     }
     
     @Override
@@ -87,6 +80,11 @@ public class PList<E, Q extends Expr<E>> extends ECollectionBase<List<E>,E> impl
         }
     }
     
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+
     @Override
     public Q get(Expr<Integer> index) {
         PathMetadata<Integer> md = PathMetadata.forListAccess(this, index);        
@@ -112,31 +110,30 @@ public class PList<E, Q extends Expr<E>> extends ECollectionBase<List<E>,E> impl
     public Class<E> getElementType() {
         return elementType;
     }
-
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
+    }
+    
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
     }
 
     @Override
-    public Path<?> getRoot() {
-        return root;
+    public int hashCode() {
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
 
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
+        return pathMixin.isNull();
     }
     
     private Q newInstance(PathMetadata<?> pm) throws Exception{
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PMap.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PMap.java
index ecefb369a..8d2d2caf8 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PMap.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PMap.java
@@ -15,8 +15,6 @@ import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.EMapBase;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 
 /**
  * PMap represents map paths
@@ -37,30 +35,24 @@ public class PMap<K, V, E extends Expr<V>> extends EMapBase<K, V> implements Pat
             PSimple.class, 
             PTime.class            
             ));
-    
-    
-    private volatile EBoolean isnull, isnotnull;
-    
+        
     private final Class<K> keyType;
     
-    private final Class<V> valueType;
+    private final Path<Map<K,V>> pathMixin;
     
     private final Class<E> queryType;
     
     private Constructor<E> queryTypeConstructor; 
     
-    private final PathMetadata<?> metadata;
+    private final Class<V> valueType;
     
-    private final Path<?> root;
-
     @SuppressWarnings("unchecked")
     public PMap(Class<? super K> keyType, Class<? super V> valueType, Class<E> queryType, PathMetadata<?> metadata) {
         super((Class)Map.class);
         this.keyType = (Class<K>) keyType;
         this.valueType = (Class<V>) valueType;
         this.queryType = queryType;
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<Map<K,V>>(this, metadata);
     }
 
     @Override
@@ -68,29 +60,14 @@ public class PMap<K, V, E extends Expr<V>> extends EMapBase<K, V> implements Pat
         v.visit(this);        
     }
     
-    @SuppressWarnings("unchecked")
+    @Override
+    public PMap<K,V,E> asExpr() {
+        return this;
+    }
+
     @Override
     public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
-    }
-    
-    private E newInstance(PathMetadata<?> pm) throws Exception{
-        if (queryTypeConstructor == null){
-            try {
-                if (typedClasses.contains(queryType)){
-                    queryTypeConstructor = queryType.getConstructor(Class.class, PathMetadata.class);   
-                }else{
-                    queryTypeConstructor = queryType.getConstructor(PathMetadata.class);    
-                }                
-            } catch (Exception e) {
-                throw new RuntimeException(e.getMessage(), e);
-            }    
-        }
-        if (typedClasses.contains(queryType)){
-            return queryTypeConstructor.newInstance(getValueType(), pm);
-        }else{
-            return queryTypeConstructor.newInstance(pm);
-        }
+        return pathMixin.equals(o);
     }
 
     @Override
@@ -112,51 +89,59 @@ public class PMap<K, V, E extends Expr<V>> extends EMapBase<K, V> implements Pat
             throw new RuntimeException(e.getMessage(), e);
         }
     }
-
+    
     @Override
     public Class<K> getKeyType() {
         return keyType;
     }
-    
+        
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
-
+    
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
-
+    
     @Override
     public Class<V> getValueType() {
         return valueType;
     }
-    
+
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
-    
+
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
-    
+
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
+        return pathMixin.isNull();
     }
     
-    @Override
-    public PMap<K,V,E> asExpr() {
-        return this;
+    private E newInstance(PathMetadata<?> pm) throws Exception{
+        if (queryTypeConstructor == null){
+            try {
+                if (typedClasses.contains(queryType)){
+                    queryTypeConstructor = queryType.getConstructor(Class.class, PathMetadata.class);   
+                }else{
+                    queryTypeConstructor = queryType.getConstructor(PathMetadata.class);    
+                }                
+            } catch (Exception e) {
+                throw new RuntimeException(e.getMessage(), e);
+            }    
+        }
+        if (typedClasses.contains(queryType)){
+            return queryTypeConstructor.newInstance(getValueType(), pm);
+        }else{
+            return queryTypeConstructor.newInstance(pm);
+        }
     }
     
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PNumber.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PNumber.java
index c8fca39c4..ba74d9a3c 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PNumber.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PNumber.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ENumber;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -22,71 +20,58 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings("serial")
 public class PNumber<D extends Number & Comparable<?>> extends ENumber<D> implements Path<D> {
     
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
+    private final Path<D> pathMixin;
+
+    public PNumber(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
+        this(type, PathMetadata.forProperty(parent, property));
+    }
 
     public PNumber(Class<? extends D> type, PathMetadata<?> metadata) {
         super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
-
-    public PNumber(Class<? extends D> type, @NotEmpty String var) {
-        this(type, PathMetadata.forVariable(var));
+        this.pathMixin = new PathMixin<D>(this, metadata);
     }
     
-    public PNumber(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
-        this(type, PathMetadata.forProperty(parent, property));
+    public PNumber(Class<? extends D> type, @NotEmpty String var) {
+        this(type, PathMetadata.forVariable(var));
     }
 
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
-    
-    @SuppressWarnings("unchecked")
-    @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
-    }
-
-    @Override
-    public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
-
-    @Override
-    public Path<?> getRoot() {
-        return root;
-    }
-
-    @Override
-    public int hashCode() {
-        return metadata.hashCode();
-    }
-
-    @Override
-    public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-    
+        
     @Override
     public ENumber<D> asExpr() {
         return this;
     }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return pathMixin.getMetadata();
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
+    }
+
+    @Override
+    public int hashCode() {
+        return pathMixin.hashCode();
+    }
+
+    @Override
+    public EBoolean isNotNull() {
+        return pathMixin.isNotNull();
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PSet.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PSet.java
index 65a1271e9..d0932286b 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PSet.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PSet.java
@@ -1,6 +1,10 @@
+/*
+ * Copyright (c) 2009 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
 package com.mysema.query.types.path;
 
-import java.util.Collection;
 import java.util.Set;
 
 import com.mysema.commons.lang.Assert;
@@ -8,8 +12,6 @@ import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ECollectionBase;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -22,23 +24,18 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings("serial")
 public class PSet<E> extends ECollectionBase<Set<E>,E> implements Path<Set<E>> {
     
-    private final PathMetadata<?> metadata;
-    
     private final Class<E> elementType;
     
     private final String entityName;
     
-    private volatile EBoolean isnull, isnotnull;    
-    
-    private final Path<?> root;
+    private final Path<Set<E>> pathMixin;
     
     @SuppressWarnings("unchecked")
     public PSet(Class<? super E> type, @NotEmpty String entityName, PathMetadata<?> metadata) {
         super((Class)Set.class);
-        this.elementType = (Class<E>) Assert.notNull(type,"type is null");
-        this.metadata = Assert.notNull(metadata,"metadata is null");
+        this.elementType = (Class<E>) Assert.notNull(type,"type is null");        
         this.entityName = Assert.notNull(entityName,"entityName is null");
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
+        this.pathMixin = new PathMixin<Set<E>>(this, metadata);
     }
 
     @Override
@@ -46,17 +43,21 @@ public class PSet<E> extends ECollectionBase<Set<E>,E> implements Path<Set<E>> {
         v.visit(this);        
     }
 
-    @SuppressWarnings("unchecked")
     @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
+    public Expr<Set<E>> asExpr() {
+        return this;
     }
 
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
     @Override
     public Class<E> getElementType() {
         return elementType;
     }
-
+    
     /**
      * Get the entity name for this Entity collection path
      * 
@@ -65,42 +66,30 @@ public class PSet<E> extends ECollectionBase<Set<E>,E> implements Path<Set<E>> {
     public String getEntityName() {
         return entityName;
     }
-
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
-    
+
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-
-    
-    @Override
-    public Expr<Set<E>> asExpr() {
-        return this;
+        return pathMixin.isNull();
     }
 
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PSimple.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PSimple.java
index 7e7c83061..727593709 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PSimple.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PSimple.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.Expr;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -22,72 +20,58 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings("serial")
 public class PSimple<D> extends Expr<D> implements Path<D> {
     
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
-
-    public PSimple(Class<? extends D> type, PathMetadata<?> metadata) {
-        super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
-
-    public PSimple(Class<? extends D> type, @NotEmpty String var) {
-        this(type, PathMetadata.forVariable(var));
-    }
+    private final Path<D> pathMixin;
     
     public PSimple(Class<? extends D> type, @NotEmpty Path<?> parent, String property) {
         this(type, PathMetadata.forProperty(parent, property));
     }
+
+    public PSimple(Class<? extends D> type, PathMetadata<?> metadata) {
+        super(type);
+        this.pathMixin = new PathMixin<D>(this, metadata);
+    }
+    
+    public PSimple(Class<? extends D> type, @NotEmpty String var) {
+        this(type, PathMetadata.forVariable(var));
+    }
     
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
-
-    @SuppressWarnings("unchecked")
-    @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
-    }
-
-    @Override
-    public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
-
-    @Override
-    public Path<?> getRoot() {
-        return root;
-    }
-
-    @Override
-    public int hashCode() {
-        return metadata.hashCode();
-    }
-
-    @Override
-    public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
     
     @Override
     public Expr<D> asExpr() {
         return this;
     }
     
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return pathMixin.getMetadata();
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
+    }
+
+    @Override
+    public int hashCode() {
+        return pathMixin.hashCode();
+    }
+
+    @Override
+    public EBoolean isNotNull() {
+        return pathMixin.isNotNull();
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PString.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PString.java
index a05164dd4..bc100bf88 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PString.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PString.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.EString;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -20,68 +18,58 @@ import com.mysema.query.util.NotEmpty;
  */
 @SuppressWarnings("serial")
 public class PString extends EString implements Path<String> {
-    
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
 
-    public PString(PathMetadata<?> metadata) {
-        this.metadata = metadata;
-    }
-
-    public PString(@NotEmpty String var) {
-        this(PathMetadata.forVariable(var));
-    }
+    private final Path<String> pathMixin;
     
     public PString(Path<?> parent, @NotEmpty String property) {
         this(PathMetadata.forProperty(parent, property));
     }
 
+    public PString(PathMetadata<?> metadata) {
+        this.pathMixin = new PathMixin<String>(this, metadata);
+    }
+    
+    public PString(@NotEmpty String var) {
+        this(PathMetadata.forVariable(var));
+    }
+
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
     
-    @SuppressWarnings("unchecked")
-    @Override
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
-    }
-
-    @Override
-    public PathMetadata<?> getMetadata() {
-        return metadata;
-    }
-
-    @Override
-    public Path<?> getRoot() {
-        return metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
-
-    @Override
-    public int hashCode() {
-        return metadata.hashCode();
-    }
-
-    @Override
-    public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
-    }
-    
-    @Override
-    public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-    
     @Override
     public EString asExpr() {
         return this;
     }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return pathMixin.getMetadata();
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return pathMixin.getRoot();
+    }
+
+    @Override
+    public int hashCode() {
+        return pathMixin.hashCode();
+    }
+
+    @Override
+    public EBoolean isNotNull() {
+        return pathMixin.isNotNull();
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        return pathMixin.isNull();
+    }
 }
\ No newline at end of file
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PTime.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PTime.java
index 2ba222e27..8b94745da 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PTime.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PTime.java
@@ -8,8 +8,6 @@ package com.mysema.query.types.path;
 import com.mysema.query.types.Visitor;
 import com.mysema.query.types.expr.EBoolean;
 import com.mysema.query.types.expr.ETime;
-import com.mysema.query.types.operation.OBoolean;
-import com.mysema.query.types.operation.Ops;
 import com.mysema.query.util.NotEmpty;
 
 /**
@@ -20,69 +18,57 @@ import com.mysema.query.util.NotEmpty;
 @SuppressWarnings({"unchecked","serial"})
 public class PTime<D extends Comparable> extends ETime<D> implements Path<D>{
 
-    private volatile EBoolean isnull, isnotnull;
-    
-    private final PathMetadata<?> metadata;
-    
-    private final Path<?> root;
-    
-    public PTime(Class<? extends D> type, PathMetadata<?> metadata) {
-        super(type);
-        this.metadata = metadata;
-        this.root = metadata.getRoot() != null ? metadata.getRoot() : this;
-    }
-
-    public PTime(Class<? extends D> type, @NotEmpty String var) {
-        this(type, PathMetadata.forVariable(var));
-    }
+    private final Path<D> pathMixin;
     
     public PTime(Class<? extends D> type, Path<?> parent, @NotEmpty String property) {
         this(type, PathMetadata.forProperty(parent, property));
     }
 
-    public boolean equals(Object o) {
-        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata)
-                : false;
+    public PTime(Class<? extends D> type, PathMetadata<?> metadata) {
+        super(type);
+        this.pathMixin = new PathMixin<D>(this, metadata);
     }
     
+    public PTime(Class<? extends D> type, @NotEmpty String var) {
+        this(type, PathMetadata.forVariable(var));
+    }    
     @Override
     public void accept(Visitor v) {
         v.visit(this);        
     }
 
+    @Override
+    public ETime<D> asExpr() {
+        return this;
+    }
+    
+    @Override
+    public boolean equals(Object o) {
+        return pathMixin.equals(o);
+    }
+    
     @Override
     public PathMetadata<?> getMetadata() {
-        return metadata;
+        return pathMixin.getMetadata();
     }
 
     @Override
     public Path<?> getRoot() {
-        return root;
+        return pathMixin.getRoot();
     }
 
     @Override
     public int hashCode() {
-        return metadata.hashCode();
+        return pathMixin.hashCode();
     }
 
     @Override
     public EBoolean isNotNull() {
-        if (isnotnull == null) {
-            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, this);
-        }
-        return isnotnull;
+        return pathMixin.isNotNull();
     }
     
     @Override
     public EBoolean isNull() {
-        if (isnull == null) {
-            isnull = OBoolean.create(Ops.IS_NULL, this);
-        }
-        return isnull;
-    }
-
-    @Override
-    public ETime<D> asExpr() {
-        return this;
+        return pathMixin.isNull();
     }
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/Path.java b/querydsl-core/src/main/java/com/mysema/query/types/path/Path.java
index 7c8886dcc..c0f011c46 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/Path.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/Path.java
@@ -15,6 +15,11 @@ import com.mysema.query.types.expr.Expr;
  * @version $Id$
  */
 public interface Path<C> {
+    /**
+     * @return
+     */
+    Expr<C> asExpr();
+
     /**
      * Get the metadata for this path
      * 
@@ -42,7 +47,7 @@ public interface Path<C> {
      * @return
      */
     EBoolean isNotNull();
-
+    
     /**
      * Create a <code>this is null</code> expression
      * 
@@ -50,10 +55,5 @@ public interface Path<C> {
      * @return
      */
     EBoolean isNull();
-    
-    /**
-     * @return
-     */
-    Expr<C> asExpr();
 
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PathInits.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PathInits.java
index 44783d136..33e8f8852 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PathInits.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PathInits.java
@@ -21,10 +21,10 @@ public class PathInits {
     
     public static final PathInits DIRECT  = new PathInits("*");
     
-    private final Map<String,PathInits> propertyToInits = new HashMap<String,PathInits>();
-    
     private boolean initAllProps = false;
     
+    private final Map<String,PathInits> propertyToInits = new HashMap<String,PathInits>();
+    
     public PathInits(String... inits){
         for (String init : inits){
             addInit(init);
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PathMetadata.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PathMetadata.java
index 94847f0e2..6a7e3a8aa 100644
--- a/querydsl-core/src/main/java/com/mysema/query/types/path/PathMetadata.java
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PathMetadata.java
@@ -67,13 +67,13 @@ public final class PathMetadata<T> implements Serializable{
 
     private final Expr<T> expression;
 
+    private final int hashCode;
+
     @Nullable
     private final Path<?> parent, root;
 
     private final PathType pathType;
 
-    private final int hashCode;
-
     private PathMetadata(@Nullable Path<?> parent, Expr<T> expression, PathType type) {
         this.parent = parent;
         this.expression = expression;
@@ -105,10 +105,6 @@ public final class PathMetadata<T> implements Serializable{
         return parent;
     }
     
-    public boolean isRoot(){
-        return parent == null;
-    }
-
     public PathType getPathType() {
         return pathType;
     }
@@ -122,4 +118,8 @@ public final class PathMetadata<T> implements Serializable{
         return hashCode;
     }
 
+    public boolean isRoot(){
+        return parent == null;
+    }
+
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/types/path/PathMixin.java b/querydsl-core/src/main/java/com/mysema/query/types/path/PathMixin.java
new file mode 100644
index 000000000..1b5b1fecf
--- /dev/null
+++ b/querydsl-core/src/main/java/com/mysema/query/types/path/PathMixin.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2009 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
+package com.mysema.query.types.path;
+
+import com.mysema.query.types.expr.EBoolean;
+import com.mysema.query.types.expr.Expr;
+import com.mysema.query.types.operation.OBoolean;
+import com.mysema.query.types.operation.Ops;
+
+/**
+ * PathMixin defines a mixin version of the Path interface which can be used 
+ * as a component and target in actual Path implementations
+ * 
+ * @author tiwe
+ *
+ * @param <T>
+ */
+class PathMixin<T> implements Path<T> {
+    
+    private volatile EBoolean isnull, isnotnull;
+    
+    private final PathMetadata<?> metadata;
+    
+    private final Path<?> root;
+    
+    private final Expr<T> self;
+    
+    @SuppressWarnings("unchecked")
+    public PathMixin(Expr<T> self, PathMetadata<?> metadata){
+        this.self = self;
+        this.metadata = metadata;
+        this.root = metadata.getRoot() != null ? metadata.getRoot() : (Path<T>)self;
+    }
+
+    @Override
+    public Expr<T> asExpr() {
+        return self;
+    }
+
+    @SuppressWarnings("unchecked")
+    public boolean equals(Object o) {
+        return o instanceof Path ? ((Path<?>) o).getMetadata().equals(metadata) : false;
+    }
+
+    @Override
+    public PathMetadata<?> getMetadata() {
+        return metadata;
+    }
+
+    @Override
+    public Path<?> getRoot() {
+        return root;
+    }
+    
+    @Override
+    public Class<? extends T> getType() {
+        return self.getType();
+    }
+
+    @Override
+    public int hashCode() {
+        return metadata.hashCode();
+    }
+    
+    @Override
+    public EBoolean isNotNull() {
+        if (isnotnull == null) {
+            isnotnull = OBoolean.create(Ops.IS_NOT_NULL, self);
+        }
+        return isnotnull;
+    }
+    
+    @Override
+    public EBoolean isNull() {
+        if (isnull == null) {
+            isnull = OBoolean.create(Ops.IS_NULL, self);
+        }
+        return isnull;
+    }
+
+}