added optional storage of constructor names and datatype names while …

…serializing to JSON. Wired this through the different webservers as well

src/org/rascalmpl/library/Content.rsc

@@ -80,7 +80,7 @@ which involves a handy, automatic, encoding of Rascal values into json values.
 data Response 
   = response(Status status, str mimeType, map[str,str] header, str content)
   | fileResponse(loc file, str mimeType, map[str,str] header)
-  | jsonResponse(Status status, map[str,str] header, value val, str dateTimeFormat = "yyyy-MM-dd\'T\'HH:mm:ss\'Z\'")
+  | jsonResponse(Status status, map[str,str] header, value val, str dateTimeFormat = "yyyy-MM-dd\'T\'HH:mm:ss\'Z\'", bool explicitConstructorNames=false, bool explicitDataTypes=false)
   ;
 
 

src/org/rascalmpl/library/lang/json/IO.java

@@ -137,7 +137,7 @@ public IValue parseJSON(IValue type, IString src, IString dateTimeFormat, IBool
 	      }
 	    }
 
-	public void writeJSON(ISourceLocation loc, IValue value, IBool unpackedLocations, IString dateTimeFormat, IBool dateTimeAsInt, IInteger indent, IBool dropOrigins) {
+	public void writeJSON(ISourceLocation loc, IValue value, IBool unpackedLocations, IString dateTimeFormat, IBool dateTimeAsInt, IInteger indent, IBool dropOrigins, IBool explicitConstructorNames, IBool explicitDataTypes) {
 	    try (JsonWriter out = new JsonWriter(new OutputStreamWriter(URIResolverRegistry.getInstance().getOutputStream(loc, false), Charset.forName("UTF8")))) {
 	        if (indent.intValue() > 0) {
 	            out.setIndent("        ".substring(0, indent.intValue() % 9));
@@ -148,13 +148,15 @@ public void writeJSON(ISourceLocation loc, IValue value, IBool unpackedLocations
 	        .setDatesAsInt(dateTimeAsInt.getValue())
 	        .setUnpackedLocations(unpackedLocations.getValue())
 			.setDropOrigins(dropOrigins.getValue())
+			.setExplicitConstructorNames(explicitConstructorNames.getValue())
+			.setExplicitDataTypes(explicitDataTypes.getValue())
 	        .write(out, value);
 	    } catch (IOException e) {
 	        throw RuntimeExceptionFactory.io(values.string(e.getMessage()), null, null);
 	    } 
 	}
 
-	public IString asJSON(IValue value, IBool unpackedLocations, IString dateTimeFormat, IBool dateTimeAsInt, IInteger indent, IBool dropOrigins) {
+	public IString asJSON(IValue value, IBool unpackedLocations, IString dateTimeFormat, IBool dateTimeAsInt, IInteger indent, IBool dropOrigins, IBool explicitConstructorNames, IBool explicitDataTypes) {
 	    StringWriter string = new StringWriter();
 
 	    try (JsonWriter out = new JsonWriter(string)) {
@@ -166,6 +168,8 @@ public IString asJSON(IValue value, IBool unpackedLocations, IString dateTimeFor
 	        	.setDatesAsInt(dateTimeAsInt.getValue())
 	        	.setUnpackedLocations(unpackedLocations.getValue())
 				.setDropOrigins(dropOrigins.getValue())
+				.setExplicitConstructorNames(explicitConstructorNames.getValue())
+				.setExplicitDataTypes(explicitDataTypes.getValue())
 	        	.write(out, value);
 
 	        return values.string(string.toString());

src/org/rascalmpl/library/lang/json/IO.rsc

@@ -15,25 +15,20 @@
 module lang::json::IO
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-@deprecated{
-use writeJSON
-}
+@deprecated{use writeJSON}
 public java str toJSON(value v);
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-@deprecated{
-use asJSON
-}
+@deprecated{use asJSON}
 public java str toJSON(value v, bool compact);
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-@deprecated{
-use readJSON
-}
+@deprecated{use readJSON}
 public java &T fromJSON(type[&T] typ, str src);
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-@synopsis{reads JSON values from a stream
+@synopsis{reads JSON values from a stream}
+@description{
 In general the translation behaves as follows:
  * Objects translate to map[str,value] by default, unless a node is expected (properties are then translated to keyword fields)
  * Arrays translate to lists by default, or to a set if that is expected or a tuple if that is expected. Arrays may also be interpreted as constructors or nodes (see below)
@@ -52,7 +47,24 @@ In general the translation behaves as the same as for ((readJSON)).}
 java &T parseJSON(type[&T] expected, str src, str dateTimeFormat = "yyyy-MM-dd\'T\'HH:mm:ssZZZZZ", bool lenient=false, bool trackOrigins=false);
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-java void writeJSON(loc target, value val, bool unpackedLocations=false, str dateTimeFormat="yyyy-MM-dd\'T\'HH:mm:ssZZZZZ", bool dateTimeAsInt=false, int indent=0, bool dropOrigins=true);
+@synopsis{Serializes a value as a JSON string and stream it}
+@description{
+This function tries to map Rascal values to JSON values in a natural way.
+In particular it tries to create a value that has the same number of recursive levels,
+such that one constructor maps to one object. The serialization is typically _lossy_ since
+JSON values by default do not explicitly encode the class or constructor while Rascal data types do.
+
+If you need the names of constructors or data-types in your result, then use the parameters:
+* `explicitConstructorNames=true` will store the name of every constructor in a field `_constructor`
+* `explicitDataTypes=true` will store the name of the ADT in a field called `_type`
+
+The `dateTimeFormat` parameter dictates how `datetime` values will be printed.
+
+The `unpackedLocations` parameter will produce an object with many fields for every property of a `loc` value, but
+if set to false a `loc` will be printed as a string.
+}
+java void writeJSON(loc target, value val, bool unpackedLocations=false, str dateTimeFormat="yyyy-MM-dd\'T\'HH:mm:ssZZZZZ", bool dateTimeAsInt=false, int indent=0, bool dropOrigins=true, bool explicitConstructorNames=false, bool explicitDataTypes=false);
 
 @javaClass{org.rascalmpl.library.lang.json.IO}
-java str asJSON(value val, bool unpackedLocations=false, str dateTimeFormat="yyyy-MM-dd\'T\'HH:mm:ssZZZZZ", bool dateTimeAsInt=false, int indent = 0, bool dropOrigins=true);
+@synopsis{Serializes a value as a JSON string and stores it as a string}
+java str asJSON(value val, bool unpackedLocations=false, str dateTimeFormat="yyyy-MM-dd\'T\'HH:mm:ssZZZZZ", bool dateTimeAsInt=false, int indent = 0, bool dropOrigins=true, bool explicitConstructorNames=false, bool explicitDataTypes=false);

src/org/rascalmpl/library/lang/json/internal/JsonValueWriter.java

@@ -44,6 +44,8 @@ public class JsonValueWriter {
   private boolean datesAsInts = true;
   private boolean unpackedLocations = false;
   private boolean dropOrigins = true;
+  private boolean explicitConstructorNames = false;
+  private boolean explicitDataTypes;
 
   public JsonValueWriter() {
     setCalendarFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
@@ -78,6 +80,16 @@ public JsonValueWriter setDropOrigins(boolean setting) {
     return this;
   }
 
+  public JsonValueWriter setExplicitConstructorNames(boolean setting) {
+    this.explicitConstructorNames = setting;
+    return this;
+  }
+
+  public JsonValueWriter setExplicitDataTypes(boolean setting) {
+    this.explicitDataTypes = setting;
+    return this;
+  }
+
   public void write(JsonWriter out, IValue value) throws IOException {
     value.accept(new IValueVisitor<Void, IOException>() {
 
@@ -229,6 +241,17 @@ public Void visitConstructor(IConstructor o) throws IOException {
         }
 
         out.beginObject();
+
+        if (explicitConstructorNames) {
+          out.name("_constructor");
+          out.value(o.getName());
+        }
+
+        if (explicitDataTypes) {
+          out.name("_type");
+          out.value(o.getType().getName());
+        }
+
         int i = 0;
         for (IValue arg : o) {
           out.name(o.getConstructorType().getFieldName(i));

src/org/rascalmpl/library/util/TermREPL.java

@@ -238,10 +238,15 @@ private void handleJSONResponse(Map<String, InputStream> output, IConstructor re
 
             IValue dtf = kws.getParameter("dateTimeFormat");
             IValue dai = kws.getParameter("dateTimeAsInt");
-
+            IValue ecn = kws.getParameter("explicitConstructorNames");
+            IValue edt = kws.getParameter("explicitDataTypes");
+
             JsonValueWriter writer = new JsonValueWriter()
                 .setCalendarFormat(dtf != null ? ((IString) dtf).getValue() : "yyyy-MM-dd\'T\'HH:mm:ss\'Z\'")
-                .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true);
+                .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true)
+                .setExplicitConstructorNames(ecn != null ? ((IBool) ecn).getValue() : false)
+                .setExplicitDataTypes(edt != null ? ((IBool) edt).getValue() : false)
+                ;
 
             final ByteArrayOutputStream baos = new ByteArrayOutputStream();
 

src/org/rascalmpl/library/util/Webserver.java

@@ -238,10 +238,15 @@ private Response translateJsonResponse(Method method, IConstructor cons) {
 
                 IValue dtf = kws.getParameter("dateTimeFormat");
                 IValue dai = kws.getParameter("dateTimeAsInt");
+                IValue ecn = kws.getParameter("explicitConstructorNames");
+                IValue edt = kws.getParameter("explicitDataTypes");
 
                 JsonValueWriter writer = new JsonValueWriter()
                     .setCalendarFormat(dtf != null ? ((IString) dtf).getValue() : "yyyy-MM-dd\'T\'HH:mm:ss\'Z\'")
-                    .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true);
+                    .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true)
+                    .setExplicitConstructorNames(ecn != null ? ((IBool) ecn).getValue() : false)
+                    .setExplicitDataTypes(edt != null ? ((IBool) edt).getValue() : false)
+                    ;
 
                 try {
                     final ByteArrayOutputStream baos = new ByteArrayOutputStream();

src/org/rascalmpl/repl/REPLContentServer.java

@@ -135,10 +135,15 @@ private static Response translateJsonResponse(Method method, IConstructor cons)
 
         IValue dtf = kws.getParameter("dateTimeFormat");
         IValue dai = kws.getParameter("dateTimeAsInt");
+        IValue ecn = kws.getParameter("explicitConstructorNames");
+        IValue edt = kws.getParameter("explicitDataTypes");
 
         JsonValueWriter writer = new JsonValueWriter()
             .setCalendarFormat(dtf != null ? ((IString) dtf).getValue() : "yyyy-MM-dd\'T\'HH:mm:ss\'Z\'")
-            .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true);
+            .setDatesAsInt(dai != null ? ((IBool) dai).getValue() : true)
+            .setExplicitConstructorNames(ecn != null ? ((IBool) ecn).getValue() : false)
+            .setExplicitDataTypes(edt != null ? ((IBool) edt).getValue() : false)
+            ;
 
         try {
             final ByteArrayOutputStream baos = new ByteArrayOutputStream();