Fixing Json character offsets via wrapping the underlying character buffer"

src/org/rascalmpl/exceptions/RuntimeExceptionFactory.java

@@ -99,6 +99,9 @@ public class RuntimeExceptionFactory {
     // NotImplemented
 	public static final Type ParseError = TF.constructor(TS, Exception, "ParseError", TF.sourceLocationType(), "location");
 
+	// this comes from lang::json::IO
+	public static final Type NoOffsetParseError = TF.constructor(TS, Exception, "NoOffsetParseError", TF.sourceLocationType(), "location", TF.integerType(), "line", TF.integerType(), "column");
+
 	public static final Type PathNotFound = TF.constructor(TS,Exception,"PathNotFound",TF.sourceLocationType(), "location");
 
 	public static final Type PermissionDenied = TF.constructor(TS,Exception,"PermissionDenied",TF.stringType(), "message");
@@ -684,7 +687,12 @@ public static Throw jsonParseError(ISourceLocation loc, String cause, String pat
 			.asWithKeywordParameters().setParameter("path", VF.string(path)));
     }   
 
-
+	public static Throw jsonParseError(ISourceLocation file, int line, int col, String cause, String path) {
+         return new Throw(VF.constructor(NoOffsetParseError, file, VF.integer(line), VF.integer(col))
+			.asWithKeywordParameters().setParameter("reason", VF.string(cause))
+			.asWithKeywordParameters().setParameter("path", VF.string(path)));
+    }
+
 	public static Throw parseError(ISourceLocation loc, AbstractAST ast, StackTrace trace) {
 		return new Throw(VF.constructor(ParseError, loc), ast != null ? ast.getLocation() : null, trace);
 	}	
@@ -793,4 +801,6 @@ public static Throw parseErrorRecovery(IValue trigger, ISourceLocation loc) {
 	public static Throw parseErrorRecoveryNoSuchField(String name, ISourceLocation loc) {
 		return new Throw(VF.constructor(ParseErrorRecovery, VF.constructor(NoSuchField, VF.string(name)), loc));
 	}
+
+
 }

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

@@ -5,13 +5,16 @@
  *
  * Contributors:
  * 
- * * Jurgen J. Vinju - Jurgen.Vinju@cwi.nl - CWI * Mark Hills - Mark.Hills@cwi.nl (CWI) * Arnold
- * Lankamp - Arnold.Lankamp@cwi.nl * Bert Lisser - Bert.Lisser@cwi.nl
+ * * Jurgen J. Vinju - Jurgen.Vinju@cwi.nl - CWI 
+ * * Mark Hills - Mark.Hills@cwi.nl (CWI) 
+ * * Arnold - Lankamp - Arnold.Lankamp@cwi.nl 
+ * * Bert Lisser - Bert.Lisser@cwi.nl
  *******************************************************************************/
 package org.rascalmpl.library.lang.json;
 
 import java.io.IOException;
 import java.io.OutputStreamWriter;
+import java.io.Reader;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.nio.charset.Charset;
@@ -38,7 +41,6 @@
 import io.usethesource.vallang.type.Type;
 import io.usethesource.vallang.type.TypeStore;
 
-import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
 
 public class IO {
@@ -51,63 +53,55 @@ public IO(IRascalValueFactory values, IRascalMonitor monitor) {
         this.monitor = monitor;
     }
 
-    public IValue readJSON(IValue type, ISourceLocation loc, IString dateTimeFormat, IBool lenient, IBool trackOrigins,
-        IFunction parsers, IMap nulls, IBool explicitConstructorNames, IBool explicitDataTypes) {
+    private IValue doReadJSON(Reader in, 
+        IValue type, ISourceLocation loc, IString dateTimeFormat, IBool lenient, IBool trackOrigins,
+        IFunction parsers, IMap nulls, IBool explicitConstructorNames, IBool explicitDataTypes) throws IOException {
+
         TypeStore store = new TypeStore();
         Type start = new TypeReifier(values).valueToType((IConstructor) type, store);
-
+        
         if (parsers.getType() instanceof ReifiedType && parsers.getType().getTypeParameters().getFieldType(0).isTop()) {
             // ignore the default parser
             parsers = null;
         }
 
-        try (JsonReader in = new JsonReader(URIResolverRegistry.getInstance().getCharacterReader(loc))) {
-            in.setLenient(lenient.getValue());
+        try {
             return new JsonValueReader(values, store, monitor, loc)
-                .setCalendarFormat(dateTimeFormat.getValue())
-                .setParsers(parsers)
-                .setNulls(unreify(nulls))
-                .setExplicitConstructorNames(explicitConstructorNames.getValue())
-                .setExplicitDataTypes(explicitDataTypes.getValue())
-                .setTrackOrigins(trackOrigins.getValue())
-                .read(in, start);
-        }
-        catch (IOException e) {
-            throw RuntimeExceptionFactory.io(e);
+                    .setCalendarFormat(dateTimeFormat.getValue())
+                    .setLenient(lenient.getValue())
+                    .setParsers(parsers) 
+                    .setNulls(unreify(nulls))
+                    .setExplicitConstructorNames(explicitConstructorNames.getValue())
+                    .setExplicitDataTypes(explicitDataTypes.getValue())
+                    .setTrackOrigins(trackOrigins.getValue())
+                    .read(in, start);
         }
         catch (NullPointerException e) {
             throw RuntimeExceptionFactory.io("NPE in error handling code");
         }
     }
+
+    public IValue readJSON(
+        IValue type, ISourceLocation loc, IString dateTimeFormat, IBool lenient, IBool trackOrigins,
+        IFunction parsers, IMap nulls, IBool explicitConstructorNames, IBool explicitDataTypes) {
 
-    private Map<Type, IValue> unreify(IMap nulls) {
-        var tr = new TypeReifier(values);
-        return nulls.stream().map(t -> (ITuple) t)
-            .collect(Collectors.toMap(t -> tr.valueToType((IConstructor) t.get(0)), t -> t.get(1)));
+        try (Reader in = URIResolverRegistry.getInstance().getCharacterReader(loc)) {
+            return doReadJSON(in, type, loc, dateTimeFormat, lenient, trackOrigins, parsers, nulls, explicitConstructorNames, explicitDataTypes);
+        }
+        catch (IOException e) {
+            throw RuntimeExceptionFactory.io(e);
+        }
     }
 
     public IValue parseJSON(IValue type, IString src, IString dateTimeFormat, IBool lenient, IBool trackOrigins,
         IFunction parsers, IMap nulls, IBool explicitConstructorNames, IBool explicitDataTypes) {
-        TypeStore store = new TypeStore();
-        Type start = new TypeReifier(values).valueToType((IConstructor) type, store);
-
-        try (JsonReader in = new JsonReader(new StringReader(src.getValue()))) {
-            in.setLenient(lenient.getValue());
-            return new JsonValueReader(values, store, monitor,null)
-                    .setCalendarFormat(dateTimeFormat.getValue())
-                    .setParsers(parsers)
-                    .setNulls(unreify(nulls))
-                    .setTrackOrigins(trackOrigins.getValue())
-                    .setExplicitConstructorNames(explicitConstructorNames.getValue())
-                    .setExplicitDataTypes(explicitDataTypes.getValue())
-                    .read(in, start);
+
+        try (Reader in = new StringReader(src.getValue())) {
+            return doReadJSON(in, type, null, dateTimeFormat, lenient, trackOrigins, parsers, nulls, explicitConstructorNames, explicitDataTypes);
         }
         catch (IOException e) {
             throw RuntimeExceptionFactory.io(e);
         }
-        catch (NullPointerException e) {
-            throw RuntimeExceptionFactory.io("NPE");
-        }
     }
 
     public void writeJSON(ISourceLocation loc, IValue value, IBool unpackedLocations, IString dateTimeFormat,
@@ -162,4 +156,10 @@ public IString asJSON(IValue value, IBool unpackedLocations, IString dateTimeFor
             throw RuntimeExceptionFactory.io(e);
         }
     }
+
+    private Map<Type, IValue> unreify(IMap nulls) {
+        var tr = new TypeReifier(values);
+        return nulls.stream().map(t -> (ITuple) t)
+            .collect(Collectors.toMap(t -> tr.valueToType((IConstructor) t.get(0)), t -> t.get(1)));
+    }    
 }

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

@@ -74,7 +74,14 @@ import Exception;
 * `cause` is a factual diagnosis of what was expected at that position, versus what was found.
 * `path` is a path query string into the JSON value from the root down to the leaf where the error was detected.
 }
-data RuntimeException(str cause="", str path="");
+@benefits{
+* ((NoOffsetParseError)) is for when accurate offset tracking is turned off. Typically this is _on_
+even if `trackOrigins=false`, when we call the json parsers from Rascal.
+}
+data RuntimeException(str cause="", str path="")
+  = ParseError(loc location)
+  | NoOffsetParseError(loc location, int line, int column)
+  ;
 
 private str DEFAULT_DATETIME_FORMAT = "yyyy-MM-dd\'T\'HH:mm:ssZ";