Fix ?. order with ??, make ?? a TOp, add tests (#158)

Author: yuxiaomao

TestHScript.hx

@@ -154,6 +154,7 @@ class TestHScript extends TestCase {
 		assertScript("ptnull?.x", null, vars);
 		assertScript("ptnull?.pt.x", null, vars);
 		assertScript("ptnull?.call()", null, vars);
+		assertScript("ptnull?.pt.call()", null, vars);
 		assertScript("pt?.x", 10, vars);
 		assertScript("pt?.call()", 11, vars);
 		assertScript("pt2null?.pt", null, vars);
@@ -162,6 +163,11 @@ class TestHScript extends TestCase {
 		assertScript("pt2?.pt", pt, vars);
 		assertScript("pt2?.pt?.x", 10, vars);
 		assertScript("pt2?.pt?.call()", 11, vars);
+		assertScript("ptnull ?? 12", 12, vars);
+		assertScript("pt2null.pt ?? 12", 12, vars);
+		assertScript("ptnull?.x ?? 12", 12, vars);
+		assertScript("pt?.x ?? 12", 10, vars);
+		assertScript("pt.y ?? 12", 12, vars);
 	}
 
 	function testIsOperator():Void {

hscript/JsInterp.hx

@@ -222,7 +222,7 @@ class JsInterp extends Interp {
 			return '$$i.get(${exprValue(e)},"$f")';
 		case EBinop(op, e1, e2):
 			switch( op ) {
-			case "+","-","*","/","%","&","|","^",">>","<<",">>>","==","!=",">=","<=",">","<":
+			case "+","-","*","/","%","&","|","^",">>","<<",">>>","==","!=",">=","<=",">","<","??":
 				return '${exprOp(e1)} $op ${exprOp(e2)}';
 			case "||","&&":
 				return '(${exprCond(e1)} $op ${exprCond(e2)})';

hscript/Parser.hx

@@ -33,7 +33,6 @@ enum Token {
 	TBrClose;
 	TDot;
 	TQuestionDot;
-	TQuestionDouble;
 	TComma;
 	TSemicolon;
 	TBkOpen;
@@ -862,10 +861,10 @@ class Parser {
 		}
 	}
 
-	function parseExprNext( e1 : Expr ) {
+	function parseExprNext( e1 : Expr, ?noOp = false ) {
 		var tk = token();
 		switch( tk ) {
-		case TOp(op):
+		case TOp(op) if( !noOp ):
 
 			if( op == "->" ) {
 				// single arg reinterpretation of `f -> e` , `(f) -> e` and `(f:T) -> e`
@@ -889,15 +888,15 @@ class Parser {
 				return parseExprNext(mk(EUnop(op,false,e1),pmin(e1)));
 			}
 			return makeBinop(op,e1,parseExpr());
-		case TId(op) if( opPriority.exists(op) ):
+		case TId(op) if( !noOp && opPriority.exists(op) ):
 			return parseExprNext(makeBinop(op,e1,parseExpr()));
 		case TDot:
 			var field = getIdent();
-			return parseExprNext(mk(EField(e1,field),pmin(e1)));
+			return parseExprNext(mk(EField(e1,field),pmin(e1)), noOp);
 		case TQuestionDot:
 			var tmp = "__a_" + (uid++);
 			push(TDot);
-			var e2 = parseExprNext(mk(EIdent(tmp),pmin(e1),pmax(e1)));
+			var e2 = parseExprNext(mk(EIdent(tmp),pmin(e1),pmax(e1)), true);
 			var e = mk(EBlock([
 				mk(EVar(tmp, null, e1), pmin(e1), pmax(e1)),
 				mk(ETernary(
@@ -906,21 +905,18 @@ class Parser {
 					e2
 				))
 			]),pmin(e1));
-			return e;
+			return parseExprNext(e, noOp);
 		case TPOpen:
-			return parseExprNext(mk(ECall(e1,parseExprList(TPClose)),pmin(e1)));
+			return parseExprNext(mk(ECall(e1,parseExprList(TPClose)),pmin(e1)), noOp);
 		case TBkOpen:
 			var e2 = parseExpr();
 			ensure(TBkClose);
-			return parseExprNext(mk(EArray(e1,e2),pmin(e1)));
-		case TQuestion:
+			return parseExprNext(mk(EArray(e1,e2),pmin(e1)), noOp);
+		case TQuestion if( !noOp ):
 			var e2 = parseExpr();
 			ensure(TDoubleDot);
 			var e3 = parseExpr();
 			return mk(ETernary(e1,e2,e3),pmin(e1),pmax(e3));
-		case TQuestionDouble:
-			var e2 = parseExpr();
-			return makeBinop("??",e1,e2);
 		default:
 			push(tk);
 			return e1;
@@ -1599,7 +1595,7 @@ class Parser {
 				if( char == ".".code )
 					return TQuestionDot;
 				if( char == "?".code )
-					return TQuestionDouble;
+					return TOp("??");
 				this.char = char;
 				return TQuestion;
 			case ":".code: return TDoubleDot;
@@ -1829,7 +1825,6 @@ class Parser {
 		case TBrClose: "}";
 		case TDot: ".";
 		case TQuestionDot: "?.";
-		case TQuestionDouble: "??";
 		case TComma: ",";
 		case TSemicolon: ";";
 		case TBkOpen: "[";