feat/error recovery robust field projection

src/org/rascalmpl/interpreter/result/ConcreteSyntaxResult.java

@@ -55,6 +55,7 @@
 				return ResultFactory.bool(Names.name(name).equals(consName), ctx);
 			}
 		}
+
 		return ResultFactory.bool(false, ctx);
 	}
 
@@ -145,6 +146,22 @@
 					}
 				}
 			}
+			else if (ProductionAdapter.isError(prod)) {
+				var eprod = ProductionAdapter.getErrorProd(prod);
+				int dot = ProductionAdapter.getErrorDot(prod);
+				IList syms = ProductionAdapter.getSymbols(eprod);
+				String tmp = Names.name(name);
+
+				// only look before the dot.
+				for (int i = 0; i < dot; i++) {
+					var sym = syms.get(i);
+					if (SymbolAdapter.isLabel((IConstructor) sym)) {
+						if (SymbolAdapter.getLabel((IConstructor) sym).equals(tmp)) {
+							return ResultFactory.bool(true, ctx);
+						}
+					}
+				}
+			}
 		}
 		return super.has(name);
 	}

src/org/rascalmpl/values/parsetrees/ProductionAdapter.java

@@ -16,6 +16,7 @@
 package org.rascalmpl.values.parsetrees;
 
 import io.usethesource.vallang.IConstructor;
+import io.usethesource.vallang.IInteger;
 import io.usethesource.vallang.IList;
 import io.usethesource.vallang.IListWriter;
 import io.usethesource.vallang.INode;
@@ -37,10 +38,15 @@
 	 * @return a constructor name if present or null otherwise
 	 */
 	public static String getConstructorName(IConstructor tree) {
-		IConstructor def = getDefined(tree);
+		if (isDefault(tree)) {
+			IConstructor def = getDefined(tree);
 
-		if (SymbolAdapter.isLabel(def)) {
-			return SymbolAdapter.getLabel(def);
+			if (SymbolAdapter.isLabel(def)) {
+				return SymbolAdapter.getLabel(def);
+			}
+		}
+		else if (isError(tree)) {
+			return "recovered";
 		}
 
 		return null;
@@ -206,4 +212,12 @@
 		}
 		return false;
 	}
+
+    public static int getErrorDot(IConstructor prod) {
+       return ((IInteger) prod.get("dot")).intValue();
+    }
+
+    public static IConstructor getErrorProd(IConstructor prod) {
+       return (IConstructor) prod.get("prod");
+    }
 }

src/org/rascalmpl/values/parsetrees/TreeAdapter.java

@@ -24,6 +24,7 @@
 import org.fusesource.jansi.Ansi.Color;
 import org.rascalmpl.exceptions.ImplementationError;
 import org.rascalmpl.interpreter.utils.LimitedResultWriter;
+import org.rascalmpl.values.IRascalValueFactory;
 import org.rascalmpl.values.RascalValueFactory;
 import org.rascalmpl.values.ValueFactoryFactory;
 import org.rascalmpl.values.parsetrees.visitors.TreeVisitor;
@@ -139,6 +140,9 @@
 	/**
 	 * This function assumes that getLabeledField does not return null for the same parameters!
 	 */
+	// TODO @PieterOlivier I guess we could extend this the way we also extended the getLabeledField.
+	// if the field is still on the parsed side of the dot then we're fine. Otherwise we could
+	// think about shifting the dot if we put in correct trees at the right places?
 	public static ITree putLabeledField(ITree tree, String field, ITree repl) {
 		if (isAppl(tree)) {
 			IConstructor prod = TreeAdapter.getProduction(tree);
@@ -190,6 +194,28 @@
 						return null;
 				}
 			}
+			else if (ProductionAdapter.isError(prod)) {
+				var eprod = ProductionAdapter.getErrorProd(prod);
+				int dot = ProductionAdapter.getErrorDot(prod);
+				int index = SymbolAdapter.indexOfLabel(ProductionAdapter.getSymbols(eprod), field);
+				IList args = getArgs(tree);
+
+				if (index != -1) {
+					if (index < dot) {
+						// changing the normal part of the tree
+						return setArgs(tree, args.put(index, repl));
+					}
+					else if (index == dot) {
+						// extending the accepted part of the tree by one field
+						eprod = prod.set("prod", IRascalValueFactory.getInstance().integer(dot + 1));
+						return setProduction(setArgs(tree, args.append(repl)), eprod);
+					}
+					else {
+						// otherwise we return null which indicates the field does not exist.
+						return null;
+					}
+				}
+			}
 		}
 
 		return null;
@@ -266,6 +292,27 @@
 						return null;
 				}
 			}
+			else if (ProductionAdapter.isError(prod)) {
+				int dot = ProductionAdapter.getErrorDot(prod);
+				IConstructor eprod = ProductionAdapter.getErrorProd(prod);
+				IList syms = ProductionAdapter.getSymbols(eprod);
+				int index = SymbolAdapter.indexOfLabel(syms, field);
+
+				if (index != -1) {
+					IConstructor sym = (IConstructor) syms.get(index);
+					sym = SymbolAdapter.stripLabelsAndConditions(sym);
+
+					if (dot <= index) {
+						// we have parsed the field so we can just return it.
+						// this is a likely scenario
+						return new FieldResult(sym, (ITree) tree.getArgs().get(index));
+					}
+					else {
+						// we simply don't have that field yet. too bad.
+						return null;
+					}
+				}
+			}
 		}
 
 		return null;