back to switch/case because of a Rascal bug; refactoring the infrastr…

…ucture from throwing exceptions to a buffer of problems; all tests pass, some throws are still in the code

shared/rascal/src/transform/Results.rsc

@@ -0,0 +1,39 @@
+@contributor{Vadim Zaytsev - vadim@grammarware.net - SWAT, CWI}
+module transform::Results
+
+import syntax::BGF;
+//import syntax::XBGF;
+
+data XBGFOutcome
+	= ok()
+	| problemProd(str msg, BGFProduction p)
+	| problemExpr(str msg, BGFExpression e)
+	| problemExpr2(str msg, BGFExpression e1, BGFExpression e2)
+	| problemNT(str msg, str x)
+	| problemNT2(str msg, str x, str y)
+	| manyProblems(list[XBGFOutcome] lst)
+	;
+
+alias XBGFResult = tuple[XBGFOutcome r,BGFGrammar g];
+
+// rules for addition
+public XBGFOutcome add(ok(), XBGFOutcome y) = y;
+public XBGFOutcome add(XBGFOutcome x, ok()) = x;
+public XBGFOutcome add(manyProblems(list[XBGFOutcome] xs),manyProblems(list[XBGFOutcome] ys)) = manyProblems(xs+ys);
+public XBGFOutcome add(XBGFOutcome x,manyProblems(list[XBGFOutcome] ys)) = manyProblems([x]+ys);
+public XBGFOutcome add(manyProblems(list[XBGFOutcome] xs),XBGFOutcome y) = manyProblems(xs+y);
+public default XBGFOutcome add(XBGFOutcome x, XBGFOutcome y) = manyProblems([x,y]);
+
+// adding two results will give both error sets and the last grammar
+public XBGFResult add(XBGFResult x, XBGFResult y) = <add(x.r,y.r),y.g>;
+
+public XBGFResult add(XBGFOutcome x, XBGFResult y) = <add(x,y.r),y.g>;
+
+public void thw(ok()) {}
+public void thw(problemProd(str msg, BGFProduction p)) {throw msg+":\n<p>";}
+public void thw(problemNT(str msg, str x)) {throw msg+": <x>";}
+public void thw(problemNT2(str msg, str x, str y)) {throw msg+": <x> and <y>";}
+public void thw(problemExpr(str msg, BGFExpression e)) {throw msg+":\n<e>";}
+public void thw(problemExpr2(str msg, BGFExpression e1, BGFExpression e2)) {throw msg+":\n<e1> and <e2>";}
+public void thw(manyProblems(list[XBGFOutcome] lst)) {for (x <- lst) thw(x);} // will not work
+public default void thw(XBGFOutcome x) {}