Fix static warnings in standard library

src/org/rascalmpl/library/lang/box/util/Tree2Box.rsc

@@ -92,7 +92,7 @@ by the user is necessary.
 default Box toBox(t:appl(Production p, list[Tree] args), FO opts = fo()) {
     // the big workhorse switch identifies all kinds of special cases for shapes of
     // grammar rules, and accidental instances (emptiness, only whitespace, etc.)
-    Symbol nl = #[\n].symbol;
+    Symbol _nl = #[\n].symbol;
     Symbol notNl = #![\n].symbol;
 
     switch (<delabel(p), args>) {
@@ -189,7 +189,7 @@ default Box toBox(t:appl(Production p, list[Tree] args), FO opts = fo()) {
         // We remove all layout node positions to make the number of children predictable
         // Comments can be recovered by `layoutDiff`. By not recursing into layout
         // positions `toBox` becomes more than twice as fast.
-        case <prod(layouts(_), _, _), list[Tree] content>:
+        case <prod(layouts(_), _, _), list[Tree] _content>:
             return NULL();
 
         // if we are given a comment node, then we can format it here for use by layoutDiff
@@ -241,7 +241,7 @@ default Box toBox(t:appl(Production p, list[Tree] args), FO opts = fo()) {
         // if the sort name is statement-like and the structure block-like, we go for 
         // vertical with indentation
         // program: "begin" Declarations decls {Statement  ";"}* body "end" ;
-        case <prod(sort(/[stm]/), [*Symbol pre, op:lit(_), *Symbol bl, cl:lit(_)], _), list[Tree] elements>:
+        case <prod(sort(/[stm]/), [*Symbol pre, _op:lit(_), *Symbol _bl, _cl:lit(_)], _), list[Tree] elements>:
             return V([
                 H([*[toBox(p, opts=opts) | Tree p <- elements[0..size(pre)]], toBox(elements[size(pre)], opts=opts)]),
                 I([V([toBox(e, opts=opts) | Tree e <- elements[size(pre)+1..-1]])]),

src/org/rascalmpl/library/lang/xml/DOM.rsc

@@ -65,7 +65,7 @@ public default value implode(Node x) { throw "can not implode node"(x); }
 
 public Node toXML(node x) 
   = element(none(), getName(x), 
-           [toXML(c) | c <- getChildren(x)] + [attribute(none(),"<key>","<annos[key]>") | annos := getAnnotations(x), key <- annos]);
+           [toXML(c) | c <- getChildren(x)] + [attribute(none(),"<key>","<params[key]>") | params := getKeywordParameters(x), key <- params]);
 public default Node toXML(value x) = charData("<x> ");
 
 

src/org/rascalmpl/library/util/Monitor.rsc

@@ -239,7 +239,7 @@ test bool unfinishedLinesAtTheEndTest() {
 // repo of issue #2138
 test bool printLongUnfinishedLine() {
   jobStart("job", totalWork=1);
-  singleString = iprintToString(("" | it + "ab" | i <- [0..1000000])); // avoid concat tree printing in chunks
+  singleString = iprintToString(("" | it + "ab" | _ <- [0..1000000])); // avoid concat tree printing in chunks
   println(singleString);
   jobStep("job", "prog", work=1);
   println("Done");