Abstract expression rewrite rule set

-

diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/PlanOptimizers.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/PlanOptimizers.java
index 37e31f3..65bd8ef 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/PlanOptimizers.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/PlanOptimizers.java
@@ -163,7 +163,10 @@ public class PlanOptimizers
                         new PushProjectionThroughExchange()));
 
         builder.add(
-                new DesugaringOptimizer(metadata, sqlParser), // Clean up all the sugar in expressions, e.g. AtTimeZone, must be run before all the other optimizers
+                new IterativeOptimizer(
+                        stats,
+                        ImmutableList.of(new DesugaringOptimizer(metadata, sqlParser)), // Clean up all the sugar in expressions, e.g. AtTimeZone, must be run before all the other optimizers
+                        ImmutableSet.copyOf(new DesugSthRuleSet().getRules())),
                 new IterativeOptimizer(
                         stats,
                         ImmutableList.of(new CanonicalizeExpressions()),
diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/RuleSet.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/RuleSet.java
index 7f3c78f..521e2ed 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/RuleSet.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/RuleSet.java
@@ -1,8 +1,22 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package com.facebook.presto.sql.planner.iterative;
 
-/**
- * Created by cox on 12.07.17.
- */
-public class RuleSet
+import java.util.Set;
+
+public interface RuleSet
 {
+    Set<Rule> getRules();
 }
diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/AbstractExpressionRewriteRuleSet.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/AbstractExpressionRewriteRuleSet.java
index a09eecb..0b17ac8 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/AbstractExpressionRewriteRuleSet.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/AbstractExpressionRewriteRuleSet.java
@@ -12,10 +12,30 @@
  * limitations under the License.
  */
 
-package com.facebook.presto.sql.planner.iterative;
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 
+package com.facebook.presto.sql.planner.iterative.rule;
+
+import com.facebook.presto.sql.planner.iterative.Rule;
+import com.facebook.presto.sql.planner.iterative.RuleSet;
+import com.facebook.presto.sql.planner.plan.PlanNode;
 import com.facebook.presto.sql.tree.Expression;
+import com.google.common.collect.ImmutableSet;
 
+import java.util.Optional;
+import java.util.Set;
 import java.util.function.Function;
 
 public class AbstractExpressionRewriteRuleSet implements RuleSet
@@ -27,8 +47,22 @@ public class AbstractExpressionRewriteRuleSet implements RuleSet
         this.rewrite = rewrite;
     }
 
-    private static final class ProjectExpressionRewriteRule implements Rule
+    @Override
+    public Set<Rule> getRules()
+    {
+        return ImmutableSet.of(
+                new ProjectExpressionRewriteRule()
+                // TODO add more
+        );
+    }
+
+    private final class ProjectExpressionRewriteRule implements Rule
     {
 
+        @Override
+        public Optional<PlanNode> apply(PlanNode node, Context context)
+        {
+            return ...;
+        }
     }
 }
diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DesugarSthRuleSet.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DesugarSthRuleSet.java
index 3e4ec2e..f6edd10 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DesugarSthRuleSet.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DesugarSthRuleSet.java
@@ -1,8 +1,27 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package com.facebook.presto.sql.planner.iterative.rule;
 
-/**
- * Created by cox on 12.07.17.
- */
-public class DesugarSthRuleSet
+import com.facebook.presto.sql.tree.Expression;
+
+import java.util.function.Function;
+
+public class DesugarSthRuleSet extends AbstractExpressionRewriteRuleSet
 {
+    public DesugarSthRuleSet(Function<Expression, Expression> rewrite)
+    {
+        super(this::desugar);
+    }
 }