EQL - Simplify nested query where expressions after parsing

src/main/java/com/avaje/ebean/Junction.java

@@ -59,11 +59,11 @@ package com.avaje.ebean;
  *          .and()
  *            .startsWith("name", "r")
  *            .eq("anniversary", onAfter)
- *            .endJunction()
+ *            .endAnd()
  *          .and()
  *            .eq("status", Customer.Status.ACTIVE)
  *            .gt("id", 0)
- *            .endJunction()
+ *            .endAnd()
  *      .order().asc("name");
  *
  * q.findList();
@@ -84,39 +84,41 @@ public interface Junction<T> extends Expression, ExpressionList<T> {
     /**
      * AND group.
      */
-    AND(" and ", ""),
+    AND(" and ", "", false),
 
     /**
      * OR group.
      */
-    OR(" or ", ""),
+    OR(" or ", "", false),
 
     /**
      * NOT group.
      */
-    NOT(" and ", "not "),
+    NOT(" and ", "not ", false),
 
     /**
      * Text search AND group.
      */
-    MUST("must", ""),
+    MUST("must", "", true),
 
     /**
      * Text search NOT group.
      */
-    MUST_NOT("must_not", ""),
+    MUST_NOT("must_not", "", true),
 
     /**
      * Text search OR group.
      */
-    SHOULD("should", "");
+    SHOULD("should", "", true);
 
-    String prefix;
-    String literal;
+    private String prefix;
+    private String literal;
+    private boolean text;
 
-    Type(String literal, String prefix) {
+    Type(String literal, String prefix, boolean text) {
       this.literal = literal;
       this.prefix = prefix;
+      this.text = text;
     }
 
     /**
@@ -132,6 +134,14 @@ public interface Junction<T> extends Expression, ExpressionList<T> {
     public String prefix() {
       return prefix;
     }
+
+    /**
+     * Return true if this is a text type.
+     */
+    public boolean isText() {
+      return text;
+    }
+
   }
 
 }

src/main/java/com/avaje/ebeaninternal/api/SpiExpression.java

@@ -13,7 +13,12 @@ import java.io.IOException;
  */
 public interface SpiExpression extends Expression {
 
-  /**
+	/**
+	 * Simplify nested expressions if possible.
+	 */
+	void simplify();
+
+	/**
    * Write the expression as an elastic search expression.
    */
   void writeDocQuery(DocQueryContext context) throws IOException;

src/main/java/com/avaje/ebeaninternal/api/SpiQuery.java

@@ -693,4 +693,8 @@ public interface SpiQuery<T> extends Query<T> {
    */
   OrmUpdateProperties getUpdateProperties();
 
+  /**
+   * Simplify nested expression lists where possible.
+   */
+  void simplifyExpressions();
 }

src/main/java/com/avaje/ebeaninternal/server/expression/AbstractExpression.java

@@ -21,6 +21,11 @@ public abstract class AbstractExpression implements SpiExpression {
     this.propName = propName;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public Object getIdEqualTo(String idName) {
     // override on SimpleExpression

src/main/java/com/avaje/ebeaninternal/server/expression/DefaultExampleExpression.java

@@ -88,6 +88,11 @@ public class DefaultExampleExpression implements SpiExpression, ExampleExpressio
     }
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
     if (!list.isEmpty()) {

src/main/java/com/avaje/ebeaninternal/server/expression/DefaultExpressionList.java

@@ -97,6 +97,16 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
     }
   }
 
+  void simplifyEntries() {
+    for (SpiExpression element : list) {
+      element.simplify();
+    }
+  }
+
+  public void simplify() {
+    simplifyEntries();
+  }
+
   /**
    * Write being aware if it is the Top level "text" expressions.
    * <p>

src/main/java/com/avaje/ebeaninternal/server/expression/ExistsQueryExpression.java

@@ -36,6 +36,11 @@ class ExistsQueryExpression implements SpiExpression, UnsupportedDocStoreExpress
     this.subQuery = null;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
     throw new IllegalStateException("Not supported");

src/main/java/com/avaje/ebeaninternal/server/expression/InQueryExpression.java

@@ -38,6 +38,11 @@ class InQueryExpression extends AbstractExpression implements UnsupportedDocStor
     this.bindParams = bindParams;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
     throw new IllegalStateException("Not supported");

src/main/java/com/avaje/ebeaninternal/server/expression/JunctionExpression.java

@@ -39,9 +39,9 @@ import java.util.Set;
  */
 class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, ExpressionList<T> {
 
-  protected final DefaultExpressionList<T> exprList;
+  protected DefaultExpressionList<T> exprList;
 
-  protected final Junction.Type type;
+  protected Junction.Type type;
 
   JunctionExpression(Junction.Type type, Query<T> query, ExpressionList<T> parent) {
     this.type = type;
@@ -56,6 +56,31 @@ class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expression
     this.exprList = exprList;
   }
 
+  /**
+   * Simplify nested expressions where possible.
+   * <p>
+   * This is expected to only used after expressions are built via query language parsing.
+   * </p>
+   */
+  public void simplify() {
+    exprList.simplifyEntries();
+
+    List<SpiExpression> list = exprList.list;
+    if (list.size() == 1 && list.get(0) instanceof JunctionExpression) {
+      JunctionExpression nested = (JunctionExpression)list.get(0);
+      if (type == Type.AND && !nested.type.isText()) {
+        // and (and (a, b, c)) -> and (a, b, c)
+        // and (not (a, b, c)) -> not (a, b, c)
+        // and (or  (a, b, c)) -> or  (a, b, c)
+        this.exprList = nested.exprList;
+        this.type = nested.type;
+      } else if (type == Type.NOT && nested.type == Type.AND) {
+        // not (and (a, b, c)) -> not (a, b, c)
+        this.exprList = nested.exprList;
+      }
+    }
+  }
+
   public SpiExpression copyForPlanKey() {
     return new JunctionExpression<T>(type, exprList.copyForPlanKey());
   }

src/main/java/com/avaje/ebeaninternal/server/expression/LogicExpression.java

@@ -57,6 +57,11 @@ abstract class LogicExpression implements SpiExpression {
     this.expTwo = (SpiExpression) expTwo;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
 

src/main/java/com/avaje/ebeaninternal/server/expression/NestedPathWrapperExpression.java

@@ -24,6 +24,11 @@ class NestedPathWrapperExpression implements SpiExpression {
     this.delegate = delegate;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
     context.startNested(nestedPath);

src/main/java/com/avaje/ebeaninternal/server/expression/NonPrepareExpression.java

@@ -8,6 +8,11 @@ import com.avaje.ebeaninternal.api.SpiExpression;
  */
 abstract class NonPrepareExpression implements SpiExpression {
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void prepareExpression(BeanQueryRequest<?> request) {
     // do nothing

src/main/java/com/avaje/ebeaninternal/server/expression/NoopExpression.java

@@ -17,6 +17,11 @@ class NoopExpression implements SpiExpression {
 
   protected static final NoopExpression INSTANCE = new NoopExpression();
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public SpiExpression copyForPlanKey() {
     return this;

src/main/java/com/avaje/ebeaninternal/server/expression/NotExpression.java

@@ -22,6 +22,11 @@ final class NotExpression implements SpiExpression {
     this.exp = (SpiExpression) exp;
   }
 
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
   @Override
   public void writeDocQuery(DocQueryContext context) throws IOException {
     context.startBoolMustNot();

src/main/java/com/avaje/ebeaninternal/server/grammer/EqlAdapter.java

@@ -27,8 +27,8 @@ class EqlAdapter<T> extends EQLBaseListener {
 
   private boolean textMode;
 
-  public EqlAdapter(Query<T> query) {
-    this.query = (SpiQuery<T>)query;
+  public EqlAdapter(SpiQuery<T> query) {
+    this.query = query;
     this.helper = new EqlAdapterHelper(this);
   }
 

src/main/java/com/avaje/ebeaninternal/server/grammer/EqlParser.java

@@ -1,6 +1,6 @@
 package com.avaje.ebeaninternal.server.grammer;
 
-import com.avaje.ebean.Query;
+import com.avaje.ebeaninternal.api.SpiQuery;
 import com.avaje.ebeaninternal.server.grammer.antlr.EQLLexer;
 import com.avaje.ebeaninternal.server.grammer.antlr.EQLParser;
 import org.antlr.v4.runtime.ANTLRInputStream;
@@ -9,7 +9,7 @@ import org.antlr.v4.runtime.tree.ParseTreeWalker;
 
 public class EqlParser {
 
-  public static <T> void parse(String raw, Query<T> query) {
+  public static <T> void parse(String raw, SpiQuery<T> query) {
 
     EQLLexer lexer = new EQLLexer(new ANTLRInputStream(raw));
     CommonTokenStream tokens = new CommonTokenStream(lexer);
@@ -20,5 +20,7 @@ public class EqlParser {
 
     ParseTreeWalker walker = new ParseTreeWalker();
     walker.walk(adapter, context);
+
+    query.simplifyExpressions();
   }
 }

src/main/java/com/avaje/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -1349,6 +1349,13 @@ public class DefaultOrmQuery<T> implements SpiQuery<T> {
     return whereExpressions;
   }
 
+  @Override
+  public void simplifyExpressions() {
+    if (whereExpressions != null) {
+      whereExpressions.simplify();
+    }
+  }
+
   @Override
   public DefaultOrmQuery<T> having(Expression expression) {
     having().add(expression);