Refactor

Author: keyboardDrummer

Source/Core/Token.cs

@@ -101,5 +101,10 @@ public int CompareTo(IToken other) {
       }
       return col.CompareTo(other.col);
     }
+
+    public override string ToString()
+    {
+      return $"({line}, {col})";
+    }
   }
 }

Source/ExecutionEngine/ExecutionEngine.cs

@@ -769,7 +769,7 @@ public async Task<IReadOnlyList<IVerificationTask>> GetVerificationTasks(Program
       var sink = new CollectingErrorSink();
       var resolutionErrors = program.Resolve(Options, sink);
 
-      string GetErrorsString() => string.Join("\n", sink.Errors.Select(t => $"({t.Token.line},{t.Token.col}): {t.Message}"));
+      string GetErrorsString() => string.Join("\n", sink.Errors.Select(t => $"{t.Token}: {t.Message}"));
       if (resolutionErrors > 0)
       {
         throw new ArgumentException($"Boogie program had {resolutionErrors} resolution errors:\n{GetErrorsString()}");