Introduce breaking changes to toString() method

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/CycleUtils.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2020, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ * WSO2 Inc. licenses this file to you 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 org.ballerinalang.jvm;
+
+import org.ballerinalang.jvm.values.api.BLink;
+
+/**
+ * This class contains the utility methods required for identifying cycles.
+ *
+ * @since Swan Lake
+ */
+public class CycleUtils {
+
+    /**
+     * Internal class which represents the link between the members of ballerina values.
+     * This is used to detect the cycles in a map or array
+     */
+    public static class Node implements BLink {
+        Object obj;
+        BLink parent;
+
+        public Node(Object obj, BLink parent) {
+            this.obj = obj;
+            this.parent = parent;
+        }
+
+        public boolean hasCyclesSoFar() {
+            Node parent = (Node) this.parent;
+            while (parent != null) {
+                if (parent.obj == obj) {
+                    return true;
+                }
+                parent = (Node) parent.parent;
+            }
+            return false;
+        }
+    }
+}

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/TableJSONDataSource.java

@@ -160,7 +160,7 @@ private static void constructJsonData(MapValueImpl record, MapValue<BString, Obj
                 break;
             case TypeTags.XML_TAG:
                 BString strVal = org.ballerinalang.jvm.StringUtils.fromString(
-                        org.ballerinalang.jvm.values.utils.StringUtils.getStringValue(record.get(key)));
+                        org.ballerinalang.jvm.values.utils.StringUtils.getStringValue(record.get(key), null));
                 jsonObject.put(StringUtils.fromString(name), strVal);
                 break;
             default:

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/TableUtils.java

@@ -29,6 +29,7 @@
 
 import java.util.Map;
 
+import static org.ballerinalang.jvm.CycleUtils.Node;
 import static org.ballerinalang.jvm.util.exceptions.BallerinaErrorReasons.TABLE_KEY_CYCLIC_VALUE_REFERENCE_ERROR;
 
 /**
@@ -103,29 +104,4 @@ public static Long hash(Object obj, Node parent) {
     public static void handleTableStore(TableValue<Object, Object> tableValue, Object key, Object value) {
         tableValue.put(key, value);
     }
-
-    /**
-     * Internal class which represents the link between the members of ballerina values.
-     * This is used to detect the cycles in a map or array
-     */
-    static class Node {
-        Object obj;
-        Node parent;
-
-        public Node(Object obj, Node parent) {
-            this.obj = obj;
-            this.parent = parent;
-        }
-
-        public boolean hasCyclesSoFar() {
-            Node parent = this.parent;
-            while (parent != null) {
-                if (parent.obj == obj) {
-                    return true;
-                }
-                parent = parent.parent;
-            }
-            return false;
-        }
-    }
 }

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/TypeConverter.java

@@ -660,7 +660,7 @@ private static String anyToString(Object sourceVal) {
         } else if (sourceVal instanceof Boolean) {
             return Boolean.toString((Boolean) sourceVal);
         } else if (sourceVal instanceof DecimalValue) {
-            return ((DecimalValue) sourceVal).stringValue();
+            return ((DecimalValue) sourceVal).stringValue(null);
         } else if (sourceVal instanceof String) {
             return (String) sourceVal;
         } else if (sourceVal == null) {

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/AbstractArrayValue.java

@@ -27,6 +27,7 @@
 import org.ballerinalang.jvm.util.exceptions.BLangExceptionHelper;
 import org.ballerinalang.jvm.util.exceptions.BallerinaException;
 import org.ballerinalang.jvm.values.api.BArray;
+import org.ballerinalang.jvm.values.api.BLink;
 import org.ballerinalang.jvm.values.api.BString;
 
 import java.io.ByteArrayOutputStream;
@@ -237,7 +238,7 @@ public void unshift(BArray values) {
     }
 
     @Override
-    public abstract String stringValue();
+    public abstract String stringValue(BLink parent);
 
     @Override
     public abstract BType getType();
@@ -265,7 +266,7 @@ public Object frozenCopy(Map<Object, Object> refs) {
 
     @Override
     public String toString() {
-        return stringValue();
+        return stringValue(null);
     }
 
     @Override

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/AbstractObjectValue.java

@@ -26,6 +26,7 @@
 import org.ballerinalang.jvm.util.Flags;
 import org.ballerinalang.jvm.util.exceptions.BLangExceptionHelper;
 import org.ballerinalang.jvm.util.exceptions.RuntimeErrors;
+import org.ballerinalang.jvm.values.api.BLink;
 import org.ballerinalang.jvm.values.api.BString;
 
 import java.util.HashMap;
@@ -87,10 +88,15 @@ public BString getStringValue(BString fieldName) {
     }
 
     @Override
-    public String stringValue() {
+    public String stringValue(BLink parent) {
         return "object " + type.toString();
     }
 
+    @Override
+    public String informalStringValue(BLink parent) {
+        return stringValue(parent);
+    }
+
     @Override
     public boolean getBooleanValue(BString fieldName) {
         return (boolean) get(fieldName);

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/ArrayValueImpl.java

@@ -18,6 +18,7 @@
 package org.ballerinalang.jvm.values;
 
 import org.ballerinalang.jvm.BallerinaErrors;
+import org.ballerinalang.jvm.CycleUtils;
 import org.ballerinalang.jvm.TypeChecker;
 import org.ballerinalang.jvm.commons.ArrayState;
 import org.ballerinalang.jvm.types.BArrayType;
@@ -30,7 +31,9 @@
 import org.ballerinalang.jvm.util.exceptions.BallerinaException;
 import org.ballerinalang.jvm.util.exceptions.RuntimeErrors;
 import org.ballerinalang.jvm.values.api.BArray;
+import org.ballerinalang.jvm.values.api.BLink;
 import org.ballerinalang.jvm.values.api.BString;
+import org.ballerinalang.jvm.values.api.BValue;
 import org.ballerinalang.jvm.values.utils.StringUtils;
 
 import java.io.IOException;
@@ -544,8 +547,8 @@ public void unshift(BArray values) {
     }
 
     @Override
-    public String stringValue() {
-        StringJoiner sj = new StringJoiner(" ");
+    public String stringValue(BLink parent) {
+        StringJoiner sj = new StringJoiner(",");
         switch (this.elementType.getTag()) {
             case TypeTags.INT_TAG:
             case TypeTags.SIGNED32_INT_TAG:
@@ -576,16 +579,36 @@ public String stringValue() {
             case TypeTags.STRING_TAG:
             case TypeTags.CHAR_STRING_TAG:
                 for (int i = 0; i < size; i++) {
-                    sj.add(bStringValues[i].getValue());
+                    sj.add(((BValue) (bStringValues[i])).informalStringValue(parent));
                 }
                 break;
             default:
                 for (int i = 0; i < size; i++) {
-                    sj.add(StringUtils.getStringValue(refValues[i]));
+                    if (refValues[i] == null) {
+                        sj.add("null");
+                    } else {
+                        BType type = TypeChecker.getType(refValues[i]);
+                        switch (type.getTag()) {
+                            case TypeTags.STRING_TAG:
+                            case TypeTags.XML_TAG:
+                            case TypeTags.XML_ELEMENT_TAG:
+                            case TypeTags.XML_ATTRIBUTES_TAG:
+                            case TypeTags.XML_COMMENT_TAG:
+                            case TypeTags.XML_PI_TAG:
+                            case TypeTags.XMLNS_TAG:
+                            case TypeTags.XML_TEXT_TAG:
+                                sj.add(((BValue) (refValues[i])).informalStringValue(new CycleUtils
+                                        .Node(this, parent)));
+                                break;
+                            default:
+                                sj.add(StringUtils.getStringValue(refValues[i], new CycleUtils.Node(this, parent)));
+                                break;
+                        }
+                    }
                 }
                 break;
         }
-        return sj.toString();
+        return "[" + sj.toString() + "]";
     }
 
     @Override
@@ -713,7 +736,7 @@ public ArrayValueImpl slice(long startIndex, long endIndex) {
 
     @Override
     public String toString() {
-        return stringValue();
+        return stringValue(null);
     }
 
     /**

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/BmpStringValue.java

@@ -18,6 +18,7 @@
 
 package org.ballerinalang.jvm.values;
 
+ import org.ballerinalang.jvm.values.api.BLink;
  import org.ballerinalang.jvm.values.api.BString;
 
  /**
@@ -60,10 +61,15 @@ public BString concat(BString str) {
      }
 
      @Override
-     public String stringValue() {
+     public String stringValue(BLink parent) {
          return value;
      }
 
+     @Override
+     public String informalStringValue(BLink parent) {
+         return "\"" + toString() + "\"";
+     }
+
      @Override
      public int hashCode() {
          return value.hashCode();

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/DecimalValue.java

@@ -24,6 +24,7 @@
 import org.ballerinalang.jvm.types.BTypes;
 import org.ballerinalang.jvm.util.BLangConstants;
 import org.ballerinalang.jvm.values.api.BDecimal;
+import org.ballerinalang.jvm.values.api.BLink;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -159,7 +160,8 @@ public long intValue() {
         }
 
         if (!isDecimalWithinIntRange(value)) {
-            throw BallerinaErrors.createNumericConversionError(this.stringValue(), BTypes.typeDecimal, BTypes.typeInt);
+            throw BallerinaErrors.createNumericConversionError(this.stringValue(null), BTypes.typeDecimal,
+                    BTypes.typeInt);
         }
         return (long) Math.rint(value.doubleValue());
     }
@@ -222,8 +224,9 @@ public boolean booleanValue() {
     /**
      * Get the string value.
      * @return string value
+     * @param parent The link to the parent node
      */
-    public String stringValue() {
+    public String stringValue(BLink parent) {
         if (this.valueKind != DecimalValueKind.OTHER) {
             return this.valueKind.getValue();
         }
@@ -519,7 +522,7 @@ public int hashCode() {
      */
     @Override
     public String toString() {
-        return this.stringValue();
+        return this.stringValue(null);
     }
 
     /**

bvm/ballerina-runtime/src/main/java/org/ballerinalang/jvm/values/ErrorValue.java

@@ -18,14 +18,19 @@
 package org.ballerinalang.jvm.values;
 
 import org.ballerinalang.jvm.BallerinaErrors;
+import org.ballerinalang.jvm.CycleUtils;
 import org.ballerinalang.jvm.TypeChecker;
 import org.ballerinalang.jvm.services.ErrorHandlerUtils;
 import org.ballerinalang.jvm.types.BErrorType;
 import org.ballerinalang.jvm.types.BType;
 import org.ballerinalang.jvm.types.BTypes;
 import org.ballerinalang.jvm.types.TypeConstants;
+import org.ballerinalang.jvm.types.TypeTags;
 import org.ballerinalang.jvm.values.api.BError;
+import org.ballerinalang.jvm.values.api.BLink;
 import org.ballerinalang.jvm.values.api.BString;
+import org.ballerinalang.jvm.values.api.BValue;
+import org.ballerinalang.jvm.values.utils.StringUtils;
 
 import java.io.PrintWriter;
 import java.util.HashMap;
@@ -73,21 +78,54 @@ public ErrorValue(BType type, BString message, ErrorValue cause, Object details)
     }
 
     @Override
-    public String stringValue() {
+    public String stringValue(BLink parent) {
+        CycleUtils.Node linkParent = new CycleUtils.Node(this, parent);
         if (isEmptyDetail()) {
-            return "error " + message.getValue();
+            return "error" + getModuleName() + "(" + ((StringValue) message).informalStringValue(linkParent) + ")";
         }
-        return "error " + message.getValue() + " " + getCauseToString() +
-                org.ballerinalang.jvm.values.utils.StringUtils.getStringValue(details);
+        return "error" + getModuleName() + "(" + ((StringValue) message).informalStringValue(linkParent) +
+                getCauseToString(linkParent) + getDetailsToString(linkParent) + ")";
     }
 
-    private String getCauseToString() {
+    private String getCauseToString(BLink parent) {
         if (cause != null) {
-            return org.ballerinalang.jvm.values.utils.StringUtils.getStringValue(cause) + " ";
+            return ", " + cause.informalStringValue(parent);
         }
         return "";
     }
 
+    private String getDetailsToString(BLink parent) {
+        StringJoiner sj = new StringJoiner(", ");
+        for (Object key : ((MapValue) details).getKeys()) {
+            Object value = ((MapValue) details).get(key);
+            if (value == null) {
+                sj.add(key + "=null");
+            } else {
+                BType type = TypeChecker.getType(value);
+                switch (type.getTag()) {
+                    case TypeTags.STRING_TAG:
+                    case TypeTags.XML_TAG:
+                    case TypeTags.XML_ELEMENT_TAG:
+                    case TypeTags.XML_ATTRIBUTES_TAG:
+                    case TypeTags.XML_COMMENT_TAG:
+                    case TypeTags.XML_PI_TAG:
+                    case TypeTags.XMLNS_TAG:
+                    case TypeTags.XML_TEXT_TAG:
+                        sj.add(key + "=" + ((BValue) value).informalStringValue(parent));
+                        break;
+                    default:
+                        sj.add(key + "=" + StringUtils.getStringValue(value, parent));
+                        break;
+                }
+            }
+        }
+        return ", " + sj.toString();
+    }
+
+    private String getModuleName() {
+        return type.getPackage().name == null ? "" : " " + type.getName() + " ";
+    }
+
     @Override
     public BType getType() {
         return type;
@@ -114,7 +152,7 @@ public void freezeDirect() {
 
     @Override
     public String toString() {
-        return stringValue();
+        return stringValue(null);
     }
 
     /**