reimplement unchain mutation in Rascal

shared/rascal/src/mutate/DeYaccify.rsc

@@ -2,8 +2,6 @@
 module mutate::DeYaccify
 
 import syntax::BGF;
-import transform::library::Util;
-import transform::library::Yacc;
 
 // NB: the deyaccification mutation works on horizontal productions,
 // while the deyaccification transformation works on vertical ones!!!

shared/rascal/src/mutate/InlineChains.rsc

@@ -0,0 +1,18 @@
+@contributor{Vadim Zaytsev - vadim@grammarware.net - SWAT, CWI}
+module mutate::InlineChains
+
+import IO;
+import syntax::BGF;
+import export::BNF;
+
+public BGFGrammar unchain_m(BGFGrammar g)
+{
+	ps = g.prods;
+	for (tp:production(_,_,nonterminal(chained)) <- [p | p:production(_,_,nonterminal(x)) <- g.prods])
+	{
+		myprods = [bp | bp:production(_,chained,_) <- ps];
+		if ([production(_,_,rhs)] := myprods)
+			ps = ps + production(tp.label,tp.lhs,rhs) - myprods - tp;
+	}
+	return grammar(g.roots,ps);
+}