Address review comments

Address review comments

modules/core/src/main/java/org/apache/synapse/SynapseConstants.java

@@ -626,7 +626,7 @@ public enum ENDPOINT_TIMEOUT_TYPE { ENDPOINT_TIMEOUT, GLOBAL_TIMEOUT, HTTP_CONNE
 
     public static final String ANALYTICS_METADATA = "ANALYTICS_METADATA";
 
-    // Constants related to SIEL
+    // Constants related to Synapse Expressions
     public static final String AND = "and";
     public static final String OR = "or";
     public static final String NOT = "not";
@@ -670,8 +670,8 @@ public enum ENDPOINT_TIMEOUT_TYPE { ENDPOINT_TIMEOUT, GLOBAL_TIMEOUT, HTTP_CONNE
 
     public static final String  PAYLOAD = "payload";
     public static final String  PAYLOAD_$ = "$";
-    public static final String  SIEL_IDENTIFIER_START = "#[";
-    public static final String  SIEL_IDENTIFIER_END = "]";
+    public static final String  SYNAPSE_EXPRESSION_IDENTIFIER_START = "${";
+    public static final String  SYNAPSE_EXPRESSION_IDENTIFIER_END = "}";
     public static final String  AXIS2 = "axis2";
     public static final String  QUERY_PARAM = "queryParams";
     public static final String  URI_PARAM = "uriParams";

modules/core/src/main/java/org/apache/synapse/config/xml/PropertyMediatorFactory.java

@@ -85,8 +85,8 @@ public Mediator createSpecificMediator(OMElement elem, Properties properties) {
                 String nameExpression = nameAttributeValue.substring(1, nameAttributeValue.length() - 1);
                 if(nameExpression.startsWith("json-eval(")) {
                     new SynapseJsonPath(nameExpression.substring(10, nameExpression.length() - 1));
-                } else if (nameExpression.startsWith(SynapseConstants.SIEL_IDENTIFIER_START) &&
-                        nameExpression.endsWith(SynapseConstants.SIEL_IDENTIFIER_END)) {
+                } else if (nameExpression.startsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_START) &&
+                        nameExpression.endsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_END)) {
                     new Synapse_Path(nameExpression.substring(2, nameExpression.length() - 1));
                 } else {
                     new SynapseXPath(nameExpression);

modules/core/src/main/java/org/apache/synapse/config/xml/SynapsePath.java

@@ -4,6 +4,7 @@
 import org.apache.axiom.om.xpath.AXIOMXPath;
 import org.apache.commons.logging.Log;
 import org.apache.synapse.MessageContext;
+import org.apache.synapse.SynapseConstants;
 import org.apache.synapse.SynapseException;
 import org.apache.synapse.transport.util.MessageHandlerProvider;
 import org.apache.synapse.transport.passthru.PassThroughConstants;
@@ -27,7 +28,7 @@ public abstract class SynapsePath extends AXIOMXPath {
 
 	public static final String X_PATH = "X_PATH";
 	public static final String JSON_PATH = "JSON_PATH";
-	public static final String SIEL_PATH = "SIEL_PATH";
+	public static final String SYNAPSE_EXPRESSIONS_PATH = "SYNAPSE_EXPRESSIONS_PATH";
 	private String pathType = null;
 
 	public DOMSynapseXPathNamespaceMap domNamespaceMap = new DOMSynapseXPathNamespaceMap();
@@ -62,8 +63,9 @@ public SynapsePath(String path, String pathType, Log log) throws JaxenException
 	private String inferPathType(String expression) {
 		if (expression.startsWith("json-eval(")) {
 			return JSON_PATH;
-		} else if(expression.startsWith("#[") && expression.endsWith("]")) {
-			return SIEL_PATH;
+		} else if(expression.startsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_START)
+				&& expression.endsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_END)) {
+			return SYNAPSE_EXPRESSIONS_PATH;
 		} else {
 			return X_PATH;
 		}

modules/core/src/main/java/org/apache/synapse/config/xml/SynapsePathFactory.java

@@ -50,8 +50,8 @@ public static org.apache.synapse.config.xml.SynapsePath getSynapsePath(OMElement
 
             if(pathAttrib.getAttributeValue().startsWith("json-eval(")) {
                 path = new SynapseJsonPath(pathAttrib.getAttributeValue().substring(10, pathAttrib.getAttributeValue().length() - 1));
-            } else if (pathAttrib.getAttributeValue().startsWith(SynapseConstants.SIEL_IDENTIFIER_START) &&
-                    pathAttrib.getAttributeValue().endsWith(SynapseConstants.SIEL_IDENTIFIER_END)) {
+            } else if (pathAttrib.getAttributeValue().startsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_START) &&
+                    pathAttrib.getAttributeValue().endsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_END)) {
                 path = new Synapse_Path(pathAttrib.getAttributeValue().substring(2, pathAttrib.getAttributeValue().length() - 1));
             } else {
                 try {

modules/core/src/main/java/org/apache/synapse/mediators/Value.java

@@ -103,8 +103,8 @@ public SynapsePath getExpression() {
                             new SynapseJsonPath(expressionString.substring(10, expressionString.length() - 1));
                     expression = expressionTypeKey;
 
-                } else if (expressionString.startsWith(SynapseConstants.SIEL_IDENTIFIER_START) &&
-                        expressionString.endsWith(SynapseConstants.SIEL_IDENTIFIER_END)) {
+                } else if (expressionString.startsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_START) &&
+                        expressionString.endsWith(SynapseConstants.SYNAPSE_EXPRESSION_IDENTIFIER_END)) {
                     expression = new Synapse_Path(
                             expressionString.substring(2, expressionString.length() - 1));
                 } else {

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/ArgumentListNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/ArgumentListNode.java

@@ -15,9 +15,9 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
 
 import java.util.ArrayList;
 import java.util.List;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/ArrayIndexNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/ArrayIndexNode.java

@@ -15,9 +15,9 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
 
 import java.util.ArrayList;
 import java.util.List;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/BinaryOperationNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/BinaryOperationNode.java

@@ -15,10 +15,10 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
 
 import java.util.function.BiFunction;
 

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/ConditionalExpressionNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/ConditionalExpressionNode.java

@@ -16,10 +16,10 @@
  *  under the License.
  */
 
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
 
 /**
  * Represents a conditional expression node ( a ? b : c ) in the AST.

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/ExpressionNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/ExpressionNode.java

@@ -16,10 +16,10 @@
  *  under the License.
  */
 
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
 
 /**
  * Represents a node in the AST.

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/ExpressionResult.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/ExpressionResult.java

@@ -16,7 +16,7 @@
  *  under the License.
  */
 
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
@@ -27,7 +27,7 @@
 import com.google.gson.JsonSyntaxException;
 import com.google.gson.internal.LazilyParsedNumber;
 import org.apache.axiom.om.OMElement;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
 
 /**
  * This class represents the result of an expression evaluation.

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/FilterExpressionNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/FilterExpressionNode.java

@@ -15,10 +15,10 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.utils.ExpressionUtils;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.utils.ExpressionUtils;
 
 import java.util.Map;
 

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/HeadersAndPropertiesAccessNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/HeadersAndPropertiesAccessNode.java

@@ -16,11 +16,11 @@
  *  under the License.
  */
 
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 import org.apache.synapse.SynapseConstants;
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
 
 /**
  * Represents a node in the abstract syntax tree that provides access to headers and properties.

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/LiteralNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/LiteralNode.java

@@ -15,11 +15,11 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
 
 /**
  * Represents a leaf node in the AST that holds a literal value.

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/PayloadAccessNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/PayloadAccessNode.java

@@ -15,7 +15,7 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
@@ -35,9 +35,9 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.synapse.SynapseConstants;
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
-import org.apache.synapse.util.synapse_path.utils.ExpressionUtils;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.utils.ExpressionUtils;
 
 import java.io.IOException;
 import java.util.EnumSet;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/PredefinedFunctionNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/PredefinedFunctionNode.java

@@ -15,14 +15,14 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 import com.google.gson.JsonArray;
 import com.google.gson.JsonPrimitive;
 import org.apache.synapse.SynapseConstants;
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
-import org.apache.synapse.util.synapse_path.exception.EvaluationException;
-import org.apache.synapse.util.synapse_path.utils.ExpressionUtils;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.exception.EvaluationException;
+import org.apache.synapse.util.synapse.expression.utils.ExpressionUtils;
 import org.jaxen.JaxenException;
 
 import java.io.UnsupportedEncodingException;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/ast/SignedExpressionNode.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/ast/SignedExpressionNode.java

@@ -15,12 +15,12 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.ast;
+package org.apache.synapse.util.synapse.expression.ast;
 
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.synapse.util.synapse_path.context.EvaluationContext;
+import org.apache.synapse.util.synapse.expression.context.EvaluationContext;
 
 /**
  * Represents a node in the AST that holds a signed expression. ex: ( -var.num1 )

modules/core/src/main/java/org/apache/synapse/util/synapse_path/context/EvaluationContext.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/context/EvaluationContext.java

@@ -15,7 +15,7 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.context;
+package org.apache.synapse.util.synapse.expression.context;
 
 import org.apache.axiom.om.OMElement;
 import org.apache.axiom.om.OMNode;
@@ -42,7 +42,7 @@
 import static org.apache.axis2.context.MessageContext.TRANSPORT_HEADERS;
 
 /**
- * Represents the evaluation context of the SIEL expressions.
+ * Represents the evaluation context of the Synapse Expressions.
  * Which provides payload and headers access.
  */
 public class EvaluationContext {

modules/core/src/main/java/org/apache/synapse/util/synapse_path/exception/EvaluationException.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/exception/EvaluationException.java

@@ -15,10 +15,10 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.exception;
+package org.apache.synapse.util.synapse.expression.exception;
 
 /**
- * Represents an exception that occurs during the evaluation of SIEL expressions.
+ * Represents an exception that occurs during the evaluation of Synapse Expressions.
  */
 public class EvaluationException extends RuntimeException {
     public EvaluationException(String message) {

modules/core/src/main/java/org/apache/synapse/util/synapse_path/exception/SyntaxError.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/exception/SyntaxError.java

@@ -15,12 +15,11 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.exception;
+package org.apache.synapse.util.synapse.expression.exception;
 
 import org.antlr.v4.runtime.RecognitionException;
-
 /**
- * Represents an exception that occurs during the parsing of SIEL expressions.
+ * Represents an exception that occurs during the parsing of Synapse Expressions.
  */
 public class SyntaxError {
     private final int line;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/exception/SyntaxErrorListener.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/exception/SyntaxErrorListener.java

@@ -15,7 +15,7 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.exception;
+package org.apache.synapse.util.synapse.expression.exception;
 
 import org.antlr.v4.runtime.BaseErrorListener;
 import org.antlr.v4.runtime.RecognitionException;
@@ -28,7 +28,7 @@
 import java.util.logging.Logger;
 
 /**
- * Represents a listener that captures syntax errors during the parsing of SIEL expressions.
+ * Represents a listener that captures syntax errors during the parsing of Synapse Expressions.
  */
 public class SyntaxErrorListener extends BaseErrorListener {
     private boolean hasErrors = false;

modules/core/src/main/java/org/apache/synapse/util/synapse_path/utils/ExpressionUtils.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/utils/ExpressionUtils.java

@@ -16,12 +16,12 @@
  *  under the License.
  */
 
-package org.apache.synapse.util.synapse_path.utils;
+package org.apache.synapse.util.synapse.expression.utils;
 
 import java.nio.charset.Charset;
 
 /**
- * Utility class for SIEL expressions.
+ * Utility class for Synapse Expressions.
  */
 public class ExpressionUtils {
     public static String escapeSpecialCharacters(String input) {

modules/core/src/main/java/org/apache/synapse/util/synapse_path/visitor/ExpressionVisitor.java → modules/core/src/main/java/org/apache/synapse/util/synapse/expression/visitor/ExpressionVisitor.java

@@ -15,20 +15,21 @@
  *  specific language governing permissions and limitations
  *  under the License.
  */
-package org.apache.synapse.util.synapse_path.visitor;
+package org.apache.synapse.util.synapse.expression.visitor;
 
 import org.apache.synapse.SynapseConstants;
-import org.apache.synapse.util.synapse_path.ExpressionParser;
-import org.apache.synapse.util.synapse_path.ExpressionParserBaseVisitor;
-import org.apache.synapse.util.synapse_path.ExpressionParserVisitor;
-import org.apache.synapse.util.synapse_path.ast.*;
+import org.apache.synapse.util.synapse.expression.ast.*;
+import org.apache.synapse.util.synapse_expression.ExpressionParser;
+import org.apache.synapse.util.synapse_expression.ExpressionParserBaseVisitor;
+import org.apache.synapse.util.synapse_expression.ExpressionParserVisitor;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 /**
- * Represents a visitor that traverses the parse tree and constructs the abstract syntax tree (AST) of the SIEL
+ * Represents a visitor that traverses the parse tree and constructs the abstract syntax tree (AST)
+ * of the Synapse Expression.
  */
 public class ExpressionVisitor extends ExpressionParserBaseVisitor<ExpressionNode>
         implements ExpressionParserVisitor<ExpressionNode> {