More import relief: add builder classes Ops and Exps which have methods for

creating common operators and expressions that don't fit nicely into the fluent
style. For example: Ops.and(expr1, expr2) is preferable to expr1.and(expr2)
and Ops.not(expr) is definitely nicer than expr.not() (which we don't even
provide).

src/java/com/samskivert/depot/Exps.java

@@ -0,0 +1,107 @@
+//
+// $Id$
+//
+// Depot library - a Java relational persistence library
+// Copyright (C) 2006-2009 Michael Bayne and Pär Winzell
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.depot;
+
+import com.samskivert.depot.expression.EpochSeconds;
+import com.samskivert.depot.expression.IntervalExp;
+import com.samskivert.depot.expression.LiteralExp;
+import com.samskivert.depot.expression.SQLExpression;
+import com.samskivert.depot.expression.ValueExp;
+
+/**
+ * Provides static methods for expression construction. For example: {@link #literal}, {@link
+ * #value} and {@link #years}.
+ */
+public class Exps
+{
+    /**
+     * Wraps the supplied object in a {@link ValueExp}.
+     */
+    public ValueExp value (Object value)
+    {
+        return new ValueExp(value);
+    }
+
+    /**
+     * Creates a {@link LiteralExp} with the supplied SQL snippet. Note: you're probably breaking
+     * cross platform compatibility by using this construction.
+     */
+    public LiteralExp literal (String text)
+    {
+        return new LiteralExp(text);
+    }
+
+    /**
+     * Creates an interval for the specified number of years.
+     */
+    public static IntervalExp years (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.YEAR, amount);
+    }
+
+    /**
+     * Creates an interval for the specified number of months.
+     */
+    public static IntervalExp months (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.MONTH, amount);
+    }
+
+    /**
+     * Creates an interval for the specified number of days.
+     */
+    public static IntervalExp days (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.DAY, amount);
+    }
+
+    /**
+     * Creates an interval for the specified number of hours.
+     */
+    public static IntervalExp hours (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.HOUR, amount);
+    }
+
+    /**
+     * Creates an interval for the specified number of minutes.
+     */
+    public static IntervalExp minutes (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.MINUTE, amount);
+    }
+
+    /**
+     * Creates an interval for the specified number of seconds.
+     */
+    public static IntervalExp seconds (int amount)
+    {
+        return new IntervalExp(IntervalExp.Unit.SECOND, amount);
+    }
+
+    /**
+     * Creates an expression that converts the supplied expression into seconds since the epoch.
+     */
+    public static EpochSeconds epochSeconds (SQLExpression expr)
+    {
+        return new EpochSeconds(expr);
+    }
+}

src/java/com/samskivert/depot/Ops.java

@@ -0,0 +1,60 @@
+//
+// $Id$
+//
+// Depot library - a Java relational persistence library
+// Copyright (C) 2006-2009 Michael Bayne and Pär Winzell
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.depot;
+
+import java.util.Collection;
+
+import com.samskivert.depot.expression.SQLExpression;
+import com.samskivert.depot.operator.And;
+import com.samskivert.depot.operator.Not;
+import com.samskivert.depot.operator.Or;
+
+/**
+ * Provides static methods for operator construction that don't fit nicely into the fluent style.
+ * For example: Ops.and(), Ops.or() and Ops.not().
+ */
+public class Ops
+{
+    public static Not not (SQLExpression expr)
+    {
+        return new Not(expr);
+    }
+
+    public static And and (Collection<? extends SQLExpression> conditions)
+    {
+        return new And(conditions);
+    }
+
+    public static And and (SQLExpression... conditions)
+    {
+        return new And(conditions);
+    }
+
+    public static Or or (Collection<? extends SQLExpression> conditions)
+    {
+        return new Or(conditions);
+    }
+
+    public static Or or (SQLExpression... conditions)
+    {
+        return new Or(conditions);
+    }
+}

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

@@ -40,54 +40,6 @@ public class IntervalExp
     /** The number of units for this interval. */
     public final int amount;
 
-    /**
-     * Creates an interval for the specified number of years.
-     */
-    public static IntervalExp years (int amount)
-    {
-        return new IntervalExp(Unit.YEAR, amount);
-    }
-
-    /**
-     * Creates an interval for the specified number of months.
-     */
-    public static IntervalExp months (int amount)
-    {
-        return new IntervalExp(Unit.MONTH, amount);
-    }
-
-    /**
-     * Creates an interval for the specified number of days.
-     */
-    public static IntervalExp days (int amount)
-    {
-        return new IntervalExp(Unit.DAY, amount);
-    }
-
-    /**
-     * Creates an interval for the specified number of hours.
-     */
-    public static IntervalExp hours (int amount)
-    {
-        return new IntervalExp(Unit.HOUR, amount);
-    }
-
-    /**
-     * Creates an interval for the specified number of minutes.
-     */
-    public static IntervalExp minutes (int amount)
-    {
-        return new IntervalExp(Unit.MINUTE, amount);
-    }
-
-    /**
-     * Creates an interval for the specified number of seconds.
-     */
-    public static IntervalExp seconds (int amount)
-    {
-        return new IntervalExp(Unit.SECOND, amount);
-    }
-
     public IntervalExp (Unit unit, int amount)
     {
         this.unit = unit;