Allow completely control the instantiation of the binary expression c…

…lass (#499)

Co-authored-by: Victor.Lalykin <[email protected]>

pebble/src/main/java/com/mitchellbosecke/pebble/extension/core/CoreExtension.java

@@ -8,6 +8,10 @@
  */
 package com.mitchellbosecke.pebble.extension.core;
 
+import static com.mitchellbosecke.pebble.operator.BinaryOperatorType.FILTER;
+import static com.mitchellbosecke.pebble.operator.BinaryOperatorType.NORMAL;
+import static com.mitchellbosecke.pebble.operator.BinaryOperatorType.TEST;
+
 import com.mitchellbosecke.pebble.extension.AbstractExtension;
 import com.mitchellbosecke.pebble.extension.Filter;
 import com.mitchellbosecke.pebble.extension.Function;
@@ -55,7 +59,6 @@
 import com.mitchellbosecke.pebble.tokenParser.ParallelTokenParser;
 import com.mitchellbosecke.pebble.tokenParser.SetTokenParser;
 import com.mitchellbosecke.pebble.tokenParser.TokenParser;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -97,26 +100,26 @@ public List<UnaryOperator> getUnaryOperators() {
   @Override
   public List<BinaryOperator> getBinaryOperators() {
     List<BinaryOperator> operators = new ArrayList<>();
-    operators.add(new BinaryOperatorImpl("or", 10, OrExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("and", 15, AndExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("is", 20, PositiveTestExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("is not", 20, NegativeTestExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("contains", 20, ContainsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("==", 30, EqualsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("equals", 30, EqualsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("!=", 30, NotEqualsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl(">", 30, GreaterThanExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("<", 30, LessThanExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl(">=", 30, GreaterThanEqualsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("<=", 30, LessThanEqualsExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("+", 40, AddExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("-", 40, SubtractExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("*", 60, MultiplyExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("/", 60, DivideExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("%", 60, ModulusExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("|", 100, FilterExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("~", 110, ConcatenateExpression.class, Associativity.LEFT));
-    operators.add(new BinaryOperatorImpl("..", 120, RangeExpression.class, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("or", 10, OrExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("and", 15, AndExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("is", 20, PositiveTestExpression::new, TEST, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("is not", 20, NegativeTestExpression::new, TEST, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("contains", 20, ContainsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("==", 30, EqualsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("equals", 30, EqualsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("!=", 30, NotEqualsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl(">", 30, GreaterThanExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("<", 30, LessThanExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl(">=", 30, GreaterThanEqualsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("<=", 30, LessThanEqualsExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("+", 40, AddExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("-", 40, SubtractExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("*", 60, MultiplyExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("/", 60, DivideExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("%", 60, ModulusExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("|", 100, FilterExpression::new, FILTER, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("~", 110, ConcatenateExpression::new, NORMAL, Associativity.LEFT));
+    operators.add(new BinaryOperatorImpl("..", 120, RangeExpression::new, NORMAL, Associativity.LEFT));
 
     return operators;
   }

pebble/src/main/java/com/mitchellbosecke/pebble/operator/BinaryOperator.java

@@ -16,7 +16,9 @@ public interface BinaryOperator {
 
   String getSymbol();
 
-  Class<? extends BinaryExpression<?>> getNodeClass();
+  BinaryExpression<?> getInstance();
+
+  BinaryOperatorType getType();
 
   Associativity getAssociativity();
 

pebble/src/main/java/com/mitchellbosecke/pebble/operator/BinaryOperatorImpl.java

@@ -8,24 +8,51 @@
  */
 package com.mitchellbosecke.pebble.operator;
 
+import com.mitchellbosecke.pebble.error.PebbleException;
 import com.mitchellbosecke.pebble.node.expression.BinaryExpression;
+import com.mitchellbosecke.pebble.node.expression.FilterExpression;
+import com.mitchellbosecke.pebble.node.expression.NegativeTestExpression;
+import com.mitchellbosecke.pebble.node.expression.PositiveTestExpression;
+import java.util.function.Supplier;
 
 public class BinaryOperatorImpl implements BinaryOperator {
 
   private final int precedence;
 
   private final String symbol;
 
-  private final Class<? extends BinaryExpression<?>> nodeClass;
+  private final Supplier<? extends BinaryExpression<?>> nodeSupplier;
+
+  private final BinaryOperatorType type;
 
   private final Associativity associativity;
 
+  /**
+   * This constuctor left for backward compatibility with custom extensions
+   */
   public BinaryOperatorImpl(String symbol, int precedence,
       Class<? extends BinaryExpression<?>> nodeClass,
       Associativity associativity) {
+    this(symbol, precedence, () -> {
+      try {
+        return nodeClass.newInstance();
+      } catch (InstantiationException | IllegalAccessException e) {
+        throw new PebbleException(e, "Error instantiating class " + nodeClass.getName());
+      }
+    }, getDefaultType(nodeClass), associativity);
+  }
+
+  /**
+   * This constuctor allows you to completely control the instantiation of the expression class
+   */
+  public BinaryOperatorImpl(String symbol, int precedence,
+      Supplier<? extends BinaryExpression<?>> nodeSupplier,
+      BinaryOperatorType type,
+      Associativity associativity) {
     this.symbol = symbol;
     this.precedence = precedence;
-    this.nodeClass = nodeClass;
+    this.nodeSupplier = nodeSupplier;
+    this.type = type;
     this.associativity = associativity;
   }
 
@@ -40,12 +67,28 @@ public String getSymbol() {
   }
 
   @Override
-  public Class<? extends BinaryExpression<?>> getNodeClass() {
-    return this.nodeClass;
+  public BinaryExpression<?> getInstance() {
+    return this.nodeSupplier.get();
+  }
+
+  @Override
+  public BinaryOperatorType getType() {
+    return this.type;
   }
 
   @Override
   public Associativity getAssociativity() {
     return this.associativity;
   }
+
+  private static BinaryOperatorType getDefaultType(Class<? extends BinaryExpression<?>> nodeClass) {
+    if (FilterExpression.class.equals(nodeClass)) {
+      return BinaryOperatorType.FILTER;
+    } else if (PositiveTestExpression.class.equals(nodeClass) || NegativeTestExpression.class
+        .equals(nodeClass)) {
+      return BinaryOperatorType.TEST;
+    } else {
+      return BinaryOperatorType.NORMAL;
+    }
+  }
 }

pebble/src/main/java/com/mitchellbosecke/pebble/operator/BinaryOperatorType.java

@@ -0,0 +1,5 @@
+package com.mitchellbosecke.pebble.operator;
+
+public enum BinaryOperatorType {
+  NORMAL, FILTER, TEST
+}

pebble/src/main/java/com/mitchellbosecke/pebble/parser/ExpressionParser.java

@@ -22,7 +22,6 @@
 import com.mitchellbosecke.pebble.node.expression.ConcatenateExpression;
 import com.mitchellbosecke.pebble.node.expression.ContextVariableExpression;
 import com.mitchellbosecke.pebble.node.expression.Expression;
-import com.mitchellbosecke.pebble.node.expression.FilterExpression;
 import com.mitchellbosecke.pebble.node.expression.FilterInvocationExpression;
 import com.mitchellbosecke.pebble.node.expression.FunctionOrMacroInvocationExpression;
 import com.mitchellbosecke.pebble.node.expression.GetAttributeExpression;
@@ -34,13 +33,12 @@
 import com.mitchellbosecke.pebble.node.expression.LiteralNullExpression;
 import com.mitchellbosecke.pebble.node.expression.LiteralStringExpression;
 import com.mitchellbosecke.pebble.node.expression.MapExpression;
-import com.mitchellbosecke.pebble.node.expression.NegativeTestExpression;
 import com.mitchellbosecke.pebble.node.expression.ParentFunctionExpression;
-import com.mitchellbosecke.pebble.node.expression.PositiveTestExpression;
 import com.mitchellbosecke.pebble.node.expression.TernaryExpression;
 import com.mitchellbosecke.pebble.node.expression.UnaryExpression;
 import com.mitchellbosecke.pebble.operator.Associativity;
 import com.mitchellbosecke.pebble.operator.BinaryOperator;
+import com.mitchellbosecke.pebble.operator.BinaryOperatorType;
 import com.mitchellbosecke.pebble.operator.UnaryOperator;
 
 import java.math.BigDecimal;
@@ -180,13 +178,12 @@ else if (token.test(Token.Type.PUNCTUATION, "{")) {
 
       // the right hand expression of the FILTER operator is handled in a
       // unique way
-      if (FilterExpression.class.equals(operator.getNodeClass())) {
+      if (operator.getType() == BinaryOperatorType.FILTER) {
         expressionRight = this.parseFilterInvocationExpression();
       }
       // the right hand expression of TEST operators is handled in a
       // unique way
-      else if (PositiveTestExpression.class.equals(operator.getNodeClass())
-          || NegativeTestExpression.class.equals(operator.getNodeClass())) {
+      else if (operator.getType() == BinaryOperatorType.TEST) {
         expressionRight = this.parseTestInvocationExpression();
       } else {
         /*
@@ -204,16 +201,16 @@ else if (PositiveTestExpression.class.equals(operator.getNodeClass())
        * expression we are creating.
        */
       BinaryExpression<?> finalExpression;
-      Class<? extends BinaryExpression<?>> operatorNodeClass = operator.getNodeClass();
+
       try {
-        finalExpression = operatorNodeClass.newInstance();
-        finalExpression.setLineNumber(this.stream.current().getLineNumber());
-      } catch (InstantiationException | IllegalAccessException e) {
+        finalExpression = operator.getInstance();
+      } catch (RuntimeException e) {
         throw new ParserException(e,
-            "Error instantiating operator node [" + operatorNodeClass.getName() + "]",
+            "Error instantiating operator node",
             token.getLineNumber(), this.stream.getFilename());
       }
 
+      finalExpression.setLineNumber(this.stream.current().getLineNumber());
       finalExpression.setLeft(expression);
       finalExpression.setRight(expressionRight);
 
@@ -578,7 +575,7 @@ public ArgumentsNode parseArguments(boolean isMacroDefinition) {
           throw new ParserException(null,
               "Positional arguments must be declared before any named arguments.",
               this.stream.current()
-              .getLineNumber(),
+                  .getLineNumber(),
               this.stream.getFilename());
         }
         positionalArgs.add(new PositionalArgumentNode(argumentValue));