Fix an issue that guards (look-behind condition to match layouts) wer…

…e added to too many patterns

rascal-textmate-core/src/main/rascal/lang/textmate/Conversion.rsc

@@ -199,7 +199,11 @@ private list[ConversionUnit] addInnerRules(list[ConversionUnit] units) {
         // Convert all units in the group to match patterns (including,
         // optimistically, multi-line units as-if they are single-line)
         for (u <- group, !u.recursive) {
-            TmRule r = toTmRule(toRegExp(u.rsc, u.prod, guard = true))
+
+            // Add the guard (i.e., look-behind condition to match layout) only
+            // when the units in the group don't begin with a delimiter
+            bool guard = nothing() := u.innerDelimiters.begin;
+            TmRule r = toTmRule(toRegExp(u.rsc, u.prod, guard = guard))
                        [name = "/inner/single/<u.name>"];
             
             rules = insertIn(rules, (u: r));

rascal-textmate-core/src/main/rascal/lang/textmate/conversiontests/Rascal.test

@@ -3,6 +3,10 @@
   "foo bar"
 # ^^^^^^^^^ Constant
 
+  "foo<x + 1>bar"
+# ^^^^^     ^^^^^ Constant
+#      ^^^^^      -Constant
+
 ### TODO: The following test shows that, currently, multi-line strings are
 ### disabled. This is because the converter determines that:
 ###   - `>` doesn't uniquely delineate interpolation (it could also be