reimplement deyaccify mutation in Rascal; fix Subgrammar

shared/rascal/src/mutate/DeYaccify.rsc

@@ -0,0 +1,50 @@
+@contributor{Vadim Zaytsev - vadim@grammarware.net - SWAT, CWI}
+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!!!
+
+public BGFGrammar deyaccify_m(BGFGrammar g)
+	= visit(g)
+	{
+		// N = N X | X   =>   N = X+
+		case production(label, lhs, choice([sequence([nonterminal(n),x]),x]))
+			=> production(label, lhs, plus(x))
+		// N = X | N X   =>   N = X+
+		case production(label, lhs, choice([x,sequence([nonterminal(n),x])]))
+			=> production(label, lhs, plus(x))
+		// N = X N | X   =>   N = X+
+		case production(label, lhs, choice([sequence([x,nonterminal(n)]),x]))
+			=> production(label, lhs, plus(x))
+		// N = X | X N   =>   N = X+
+		case production(label, lhs, choice([x,sequence([x,nonterminal(n)])]))
+			=> production(label, lhs, plus(x))
+		// N = X N | e   =>   N = X*
+		case production(label, lhs, choice([sequence([x,nonterminal(n)]),epsilon()]))
+			=> production(label, lhs, star(x))
+		// N = e | X N   =>   N = X*
+		case production(label, lhs, choice([epsilon(),sequence([x,nonterminal(n)])]))
+			=> production(label, lhs, star(x))
+		// N = N X | e   =>   N = X*
+		case production(label, lhs, choice([sequence([nonterminal(n),x]),epsilon()]))
+			=> production(label, lhs, star(x))
+		// N = e | N X   =>   N = X*
+		case production(label, lhs, choice([epsilon(),sequence([nonterminal(n),x])]))
+			=> production(label, lhs, star(x))
+		// N = N X | Y   =>   N = Y X*
+		case production(label, lhs, choice([sequence([nonterminal(n),x]),y]))
+			=> production(label, lhs, sequence([y,star(x)]))
+		// N = Y | N X   =>   N = Y X*
+		case production(label, lhs, choice([y,sequence([nonterminal(n),x])]))
+			=> production(label, lhs, sequence([y,star(x)]))
+		// N = X N | Y   =>   N = X* Y
+		case production(label, lhs, choice([sequence([x,nonterminal(n)]),y]))
+			=> production(label, lhs, sequence([star(x),y]))
+		// N = Y | X N   =>   N = X* Y
+		case production(label, lhs, choice([y,sequence([x,nonterminal(n)])]))
+			=> production(label, lhs, sequence([star(x),y]))
+	};

shared/rascal/src/mutate/Subgrammar.rsc

@@ -1,20 +1,24 @@
 @contributor{Vadim Zaytsev - vadim@grammarware.net - SWAT, CWI}
 module mutate::Subgrammar
 
+import lib::Rascalware;
 import syntax::BGF;
 import transform::library::Util;
 
 public BGFGrammar subgrammar(BGFGrammar g, str root)
 {
 	BGFProdList ps = [];
 	set[str] covered = {}, uncovered = {root};
+	while(!isEmpty(uncovered))
 	for(str nt <- uncovered)
 	{
 		newps = [p | p:production(_,nt,_) <- g.prods];
 		newnts = {n | /nonterminal(n) := newps};
 		ps += newps;
-		covered += newnts;
+		uncovered += (newnts - covered);
 		uncovered -= nt;
+		covered += nt;
+		//println("Covered: <covered>\nUncovered: <uncovered>");
 	}
 	return grammar([root],ps);
 }