We'd accidentally conflated SQL expressions and SQL clauses into the one interface SQLExpressionsf, which would allow statements like 'FooRecord.BAR.add(FooRecord.getKey(1))' to compile erroneously. Let SQLExpressions and QueryClauses both be subclasses of a new type SQLFragment, and let our ExpressionVisitor be a FragmentVisitor.

src/java/com/samskivert/depot/Key.java

@@ -35,7 +35,7 @@ import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
 import com.samskivert.depot.impl.DepotMarshaller;
 import com.samskivert.depot.impl.DepotUtil;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * A special form of {@link WhereClause} that uniquely specifies a single database row and thus
@@ -60,7 +60,7 @@ public class Key<T extends PersistentRecord> extends WhereClause
         public Comparable<?>[] getValues () {
             return _values;
         }
-        public Object accept (ExpressionVisitor<?> builder) {
+        public Object accept (FragmentVisitor<?> builder) {
             return builder.visit(this);
         }
         public void addClasses (Collection<Class<? extends PersistentRecord>> classSet) {
@@ -205,7 +205,7 @@ public class Key<T extends PersistentRecord> extends WhereClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/KeySet.java

@@ -37,7 +37,7 @@ import com.samskivert.depot.clause.WhereClause;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
 import com.samskivert.depot.impl.DepotUtil;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.LiteralExp;
 import com.samskivert.depot.impl.operator.In;
 
@@ -291,7 +291,7 @@ public abstract class KeySet<T extends PersistentRecord> extends WhereClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/SQLFragment.java

@@ -0,0 +1,29 @@
+package com.samskivert.depot;
+
+import java.util.Collection;
+
+import com.samskivert.depot.impl.FragmentVisitor;
+import com.samskivert.depot.impl.SQLBuilder;
+
+/**
+ * Represents a fragment of an SQL statement, generally a clause (WHERE, FROM, ...) or an
+ * expression (1+1, 'foo', "columnName", ...).
+ */
+public interface SQLFragment
+{
+    /**
+     * Most uses of this class have been implemented with a visitor pattern. Create your own
+     * {@link FragmentVisitor} and call this method with it.
+     *
+     * @see SQLBuilder
+     */
+    public Object accept (FragmentVisitor<?> visitor);
+
+    /**
+     * Adds all persistent classes that are brought into the SQL context by this clause: FROM
+     * clauses, JOINs, UPDATEs, anything that could create a new table abbreviation. This method
+     * should recurse into any subordinate state that may in turn bring in new classes so that
+     * sub-queries work correctly.
+     */
+    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet);
+}

src/java/com/samskivert/depot/clause/FieldDefinition.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.LiteralExp;
 
 /**
@@ -81,7 +81,7 @@ public class FieldDefinition implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> visitor)
+    public Object accept (FragmentVisitor<?> visitor)
     {
         return visitor.visit(this);
     }

src/java/com/samskivert/depot/clause/ForUpdate.java

@@ -23,7 +23,7 @@ package com.samskivert.depot.clause;
 import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  *  Represents a FOR UPDATE clause.
@@ -31,7 +31,7 @@ import com.samskivert.depot.impl.ExpressionVisitor;
 public class ForUpdate implements QueryClause
 {
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/FromOverride.java

@@ -27,7 +27,7 @@ import com.google.common.collect.Lists;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.impl.DepotUtil;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  *  Completely overrides the FROM clause, if it exists.
@@ -63,7 +63,7 @@ public class FromOverride implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/GroupBy.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  *  Represents a GROUP BY clause.
@@ -42,7 +42,7 @@ public class GroupBy implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/InsertClause.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 import java.util.Set;
 
 import com.samskivert.depot.PersistentRecord;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Builds actual SQL given a main persistent type and some {@link QueryClause} objects.
@@ -62,7 +62,7 @@ public class InsertClause implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/Join.java

@@ -26,7 +26,7 @@ import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
 import com.samskivert.depot.impl.DepotUtil;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.operator.Equals;
 
 /**
@@ -74,7 +74,7 @@ public class Join implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/Limit.java

@@ -23,7 +23,7 @@ package com.samskivert.depot.clause;
 import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  *  Represents a LIMIT/OFFSET clause, for pagination.
@@ -47,7 +47,7 @@ public class Limit implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/OrderBy.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.util.ArrayUtil;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.LiteralExp;
 
 /**
@@ -95,7 +95,7 @@ public class OrderBy implements QueryClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/QueryClause.java

@@ -20,11 +20,11 @@
 
 package com.samskivert.depot.clause;
 
-import com.samskivert.depot.expression.SQLExpression;
+import com.samskivert.depot.SQLFragment;
 
 /**
  * Represents a piece or modifier of an SQL query.
  */
-public interface QueryClause extends SQLExpression
+public interface QueryClause extends SQLFragment
 {
 }

src/java/com/samskivert/depot/clause/SelectClause.java

@@ -30,7 +30,7 @@ import com.google.common.collect.Maps;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Represents a complete select clause.
@@ -193,7 +193,7 @@ public class SelectClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/clause/Where.java

@@ -26,7 +26,7 @@ import com.samskivert.depot.Ops;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.ValueExp;
 import com.samskivert.depot.impl.operator.Equals;
 import com.samskivert.depot.impl.operator.IsNull;
@@ -73,7 +73,7 @@ public class Where extends WhereClause
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/expression/ColumnExp.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.clause.Join;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.operator.In;
 import com.samskivert.depot.impl.operator.IsNull;
 import com.samskivert.depot.impl.operator.Like;
@@ -92,7 +92,7 @@ public class ColumnExp extends FluentExp
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/expression/SQLExpression.java

@@ -20,16 +20,12 @@
 
 package com.samskivert.depot.expression;
 
-import java.util.Collection;
-
-import com.samskivert.depot.PersistentRecord;
-import com.samskivert.depot.impl.ExpressionVisitor;
-import com.samskivert.depot.impl.SQLBuilder;
+import com.samskivert.depot.SQLFragment;
 
 /**
  * Represents an SQL expression, e.g. column name, function, or constant.
  */
-public interface SQLExpression
+public interface SQLExpression extends SQLFragment
 {
     /** Used internally to represent the lack of a value. */
     public static final class NoValue
@@ -46,19 +42,4 @@ public interface SQLExpression
         protected String _reason;
     }
 
-    /**
-     * Most uses of this class have been implemented with a visitor pattern. Create your own
-     * {@link ExpressionVisitor} and call this method with it.
-     *
-     * @see SQLBuilder
-     */
-    public Object accept (ExpressionVisitor<?> visitor);
-
-    /**
-     * Adds all persistent classes that are brought into the SQL context by this clause: FROM
-     * clauses, JOINs, UPDATEs, anything that could create a new table abbreviation. This method
-     * should recurse into any subordinate state that may in turn bring in new classes so that
-     * sub-queries work correctly.
-     */
-    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet);
 }

src/java/com/samskivert/depot/impl/BuildVisitor.java

@@ -102,7 +102,7 @@ import com.samskivert.depot.impl.operator.Not;
  * Implements the base functionality of the SQL-building pass of {@link SQLBuilder}. Dialectal
  * subclasses of this should be created and returned from {@link SQLBuilder#getBuildVisitor()}.
  */
-public abstract class BuildVisitor implements ExpressionVisitor<Void>
+public abstract class BuildVisitor implements FragmentVisitor<Void>
 {
     public String getQuery ()
     {

src/java/com/samskivert/depot/impl/ExpressionEvaluator.java

@@ -100,7 +100,7 @@ import static com.samskivert.depot.Log.log;
  * TODO: that should be written.
  */
 public class ExpressionEvaluator
-    implements ExpressionVisitor<Object>
+    implements FragmentVisitor<Object>
 {
     public <T extends PersistentRecord> ExpressionEvaluator (Class<T> pClass, T pRec)
     {

src/java/com/samskivert/depot/impl/FragmentVisitor.java

@@ -85,7 +85,7 @@ import com.samskivert.depot.impl.operator.Not;
 /**
  * Enumerates visitation methods for every possible SQL expression type.
  */
-public interface ExpressionVisitor<T>
+public interface FragmentVisitor<T>
 {
     public T visit (FieldDefinition fieldOverride);
     public T visit (FromOverride fromOverride);

src/java/com/samskivert/depot/impl/SQLBuilder.java

@@ -39,7 +39,7 @@ import com.samskivert.util.ByteEnum;
 import static com.samskivert.depot.Log.log;
 
 /**
- * At the heart of Depot's SQL generation, this object constructs an {@link ExpressionVisitor}
+ * At the heart of Depot's SQL generation, this object constructs an {@link FragmentVisitor}
  * object and executes it, constructing SQL and parameter bindings as it recurses.
  */
 public abstract class SQLBuilder

src/java/com/samskivert/depot/impl/clause/CreateIndexClause.java

@@ -30,7 +30,7 @@ import com.samskivert.depot.clause.OrderBy.Order;
 import com.samskivert.depot.clause.QueryClause;
 import com.samskivert.depot.expression.SQLExpression;
 
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Represents an CREATE INDEX instruction to the database.
@@ -71,14 +71,14 @@ public class CreateIndexClause
         return _fields;
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         classSet.add(_pClass);
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/clause/DeleteClause.java

@@ -26,7 +26,7 @@ import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.clause.QueryClause;
 import com.samskivert.depot.clause.WhereClause;
 
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Builds actual SQL given a main persistent type and some {@link QueryClause} objects.
@@ -50,14 +50,14 @@ public class DeleteClause
         return _where;
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         classSet.add(_pClass);
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/clause/DropIndexClause.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.clause.QueryClause;
 
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Represents an DROP INDEX instruction to the database.
@@ -49,14 +49,14 @@ public class DropIndexClause
         return _name;
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         classSet.add(_pClass);
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/clause/UpdateClause.java

@@ -28,7 +28,7 @@ import com.samskivert.depot.clause.WhereClause;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
 
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Builds actual SQL given a main persistent type and some {@link QueryClause} objects.
@@ -81,7 +81,7 @@ public class UpdateClause
         return _pClass;
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         classSet.add(_pClass);
@@ -95,8 +95,8 @@ public class UpdateClause
         }
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/expression/AggregateFun.java

@@ -21,7 +21,7 @@
 package com.samskivert.depot.impl.expression;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.Function.OneArgFun;
 
 public abstract class AggregateFun extends OneArgFun
@@ -33,7 +33,7 @@ public abstract class AggregateFun extends OneArgFun
         public Average (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -48,7 +48,7 @@ public abstract class AggregateFun extends OneArgFun
         public Count (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -63,7 +63,7 @@ public abstract class AggregateFun extends OneArgFun
         public Every (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -78,7 +78,7 @@ public abstract class AggregateFun extends OneArgFun
         public Max (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -93,7 +93,7 @@ public abstract class AggregateFun extends OneArgFun
         public Min (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -108,7 +108,7 @@ public abstract class AggregateFun extends OneArgFun
         public Sum (SQLExpression argument, boolean distinct) {
             super(argument, distinct);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {

src/java/com/samskivert/depot/impl/expression/ConditionalFun.java

@@ -21,7 +21,7 @@
 package com.samskivert.depot.impl.expression;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.Function.ManyArgFun;
 
 public abstract class ConditionalFun
@@ -30,7 +30,7 @@ public abstract class ConditionalFun
         public Coalesce (SQLExpression... args) {
             super(args);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -42,7 +42,7 @@ public abstract class ConditionalFun
         public Greatest (SQLExpression... args) {
             super(args);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -54,7 +54,7 @@ public abstract class ConditionalFun
         public Least (SQLExpression... args) {
             super(args);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {

src/java/com/samskivert/depot/impl/expression/DateFun.java

@@ -21,7 +21,7 @@
 package com.samskivert.depot.impl.expression;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.Function.NoArgFun;
 import com.samskivert.depot.impl.expression.Function.OneArgFun;
 
@@ -36,7 +36,7 @@ public abstract class DateFun
             super(date);
             _part = part;
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public Part getPart () {
@@ -64,7 +64,7 @@ public abstract class DateFun
             super(date);
             _truncation= truncation;
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public Truncation getTruncation () {
@@ -77,7 +77,7 @@ public abstract class DateFun
     }
 
     public static class Now extends NoArgFun {
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {

src/java/com/samskivert/depot/impl/expression/IntervalExp.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * A code for representing a date interval.
@@ -47,13 +47,13 @@ public class IntervalExp
         this.amount = amount;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
     }

src/java/com/samskivert/depot/impl/expression/LiteralExp.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * An expression for things we don't support natively, e.g. COUNT(*).
@@ -38,13 +38,13 @@ public class LiteralExp
         _text = text;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
     }

src/java/com/samskivert/depot/impl/expression/NumericalFun.java

@@ -21,7 +21,7 @@
 package com.samskivert.depot.impl.expression;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.Function.NoArgFun;
 import com.samskivert.depot.impl.expression.Function.OneArgFun;
 import com.samskivert.depot.impl.expression.Function.TwoArgFun;
@@ -32,7 +32,7 @@ public abstract class NumericalFun
         public Abs (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -44,7 +44,7 @@ public abstract class NumericalFun
         public Ceil (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -56,7 +56,7 @@ public abstract class NumericalFun
         public Exp (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -68,7 +68,7 @@ public abstract class NumericalFun
         public Floor (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -80,7 +80,7 @@ public abstract class NumericalFun
         public Ln (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -92,7 +92,7 @@ public abstract class NumericalFun
         public Log10 (SQLExpression value) {
             super(value);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -101,7 +101,7 @@ public abstract class NumericalFun
     }
 
     public static class Pi extends NoArgFun {
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -113,7 +113,7 @@ public abstract class NumericalFun
         public Power (SQLExpression value, SQLExpression power) {
             super(value, power);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -128,7 +128,7 @@ public abstract class NumericalFun
     }
 
     public static class Random extends NoArgFun {
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -140,7 +140,7 @@ public abstract class NumericalFun
         public Round (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -152,7 +152,7 @@ public abstract class NumericalFun
         public Sign (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -164,7 +164,7 @@ public abstract class NumericalFun
         public Sqrt (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -176,7 +176,7 @@ public abstract class NumericalFun
         public Trunc (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {

src/java/com/samskivert/depot/impl/expression/StringFun.java

@@ -21,7 +21,7 @@
 package com.samskivert.depot.impl.expression;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.Function.ManyArgFun;
 import com.samskivert.depot.impl.expression.Function.OneArgFun;
 import com.samskivert.depot.impl.expression.Function.TwoArgFun;
@@ -32,7 +32,7 @@ public abstract class StringFun
         public Length (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -44,7 +44,7 @@ public abstract class StringFun
         public Lower (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -56,7 +56,7 @@ public abstract class StringFun
         public Position (SQLExpression substring, SQLExpression string) {
             super(substring, string);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -74,7 +74,7 @@ public abstract class StringFun
         public Substring (SQLExpression string, SQLExpression from, SQLExpression count) {
             super(string, from, count);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -86,7 +86,7 @@ public abstract class StringFun
         public Trim (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {
@@ -98,7 +98,7 @@ public abstract class StringFun
         public Upper (SQLExpression argument) {
             super(argument);
         }
-        public Object accept (ExpressionVisitor<?> visitor) {
+        public Object accept (FragmentVisitor<?> visitor) {
             return visitor.visit(this);
         }
         public String getCanonicalFunctionName () {

src/java/com/samskivert/depot/impl/expression/ValueExp.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.FluentExp;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * A Java value that is bound as a parameter to the query, e.g. 1 or 'abc'.
@@ -36,13 +36,13 @@ public class ValueExp extends FluentExp
         _value = value;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
     }

src/java/com/samskivert/depot/impl/operator/BinaryOperator.java

@@ -4,7 +4,7 @@
 package com.samskivert.depot.impl.operator;
 
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.depot.impl.expression.ValueExp;
 
 /**
@@ -32,8 +32,8 @@ public abstract class BinaryOperator extends BaseOperator
      */
     public abstract Object evaluate (Object left, Object right);
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/operator/Exists.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.clause.SelectClause;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * The SQL 'exists' operator.
@@ -38,7 +38,7 @@ public class Exists
         _clause = clause;
     }
 
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/impl/operator/In.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * The SQL 'in (...)' operator.
@@ -57,13 +57,13 @@ public class In
         return _values;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         _column.addClasses(classSet);

src/java/com/samskivert/depot/impl/operator/IsNull.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.ColumnExp;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * The SQL 'is null' operator.
@@ -43,13 +43,13 @@ public class IsNull
         return _column;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
     }

src/java/com/samskivert/depot/impl/operator/MultiOperator.java

@@ -7,7 +7,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Represents an operator with any number of operands.
@@ -29,13 +29,13 @@ public abstract class MultiOperator extends BaseOperator
      */
     public abstract Object evaluate (Object[] values);
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    @Override // from SQLExpression
+    @Override // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         for (SQLExpression operand : _args) {

src/java/com/samskivert/depot/impl/operator/Not.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * Represents the truth negation of another conditon.
@@ -42,13 +42,13 @@ public class Not
         return _condition;
     }
 
-    // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    // from SQLFragment
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }
 
-    // from SQLExpression
+    // from SQLFragment
     public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
     {
         _condition.addClasses(classSet);

src/java/com/samskivert/depot/operator/Case.java

@@ -27,7 +27,7 @@ import com.google.common.collect.Lists;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 import com.samskivert.util.Tuple;
 
 /**
@@ -57,7 +57,7 @@ public class Case
     }
 
     // from SQLExpression
-    public Object accept (ExpressionVisitor<?> builder)
+    public Object accept (FragmentVisitor<?> builder)
     {
         return builder.visit(this);
     }

src/java/com/samskivert/depot/operator/FullText.java

@@ -24,7 +24,7 @@ import java.util.Collection;
 
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.FluentExp;
-import com.samskivert.depot.impl.ExpressionVisitor;
+import com.samskivert.depot.impl.FragmentVisitor;
 
 /**
  * An attempt at a dialect-agnostic full-text search condition, such as MySQL's MATCH() and
@@ -35,7 +35,7 @@ public class FullText
     public class Rank extends FluentExp
     {
         // from SQLExpression
-        public Object accept (ExpressionVisitor<?> builder)
+        public Object accept (FragmentVisitor<?> builder)
         {
             return builder.visit(this);
         }
@@ -60,7 +60,7 @@ public class FullText
     public class Match extends FluentExp
     {
         // from SQLExpression
-        public Object accept (ExpressionVisitor<?> builder)
+        public Object accept (FragmentVisitor<?> builder)
         {
             return builder.visit(this);
         }