Add flag to control error output format

Author: prenaux

source/common.h

@@ -104,6 +104,15 @@ struct comment
 //
 struct error
 {
+    // Controls whether we print `FILE:line:col: error:` or `FILE(line,col):
+    // error:`.  Need to integrate with editors that jump to errors, etc.
+    // TODO: This should become a compiler flag.
+#ifdef _MSC_VER
+    static constexpr bool print_colon_errors = false;
+#else
+    static constexpr bool print_colon_errors = true;
+#endif
+
     source_position where;
     std::string     msg;
     bool            internal = false;
@@ -116,11 +125,19 @@ struct error
     {
         o << file ;
         if (where.lineno > 0) {
-            o << "("<< (where.lineno);
-            if (where.colno >= 0) {
-                o << "," << where.colno;
+            if (print_colon_errors) {
+                o << ":"<< (where.lineno);
+                if (where.colno >= 0) {
+                    o << ":" << where.colno;
+                }
+            }
+            else {
+                o << "("<< (where.lineno);
+                if (where.colno >= 0) {
+                    o << "," << where.colno;
+                }
+                o  << ")";
             }
-            o  << ")";
         }
         o << ":";
         if (internal) {