"cast" syntax support

- Now it parses unsafe/safe cast. For now it's just sugar syntax.

hscript/Bytes.hx

@@ -130,6 +130,8 @@ class Bytes {
 			// TODO
 		case EEnum(en):
 			// TODO
+		case ECast(e, _):
+			// TODO
 		case EConst(c):
 			doEncodeConst(c);
 		case EIdent(v):

hscript/Expr.hx

@@ -82,6 +82,7 @@ enum Expr {
 	EImport( c : String, ?asname:String, ?isUsing:Bool );
 	EClass( name:String, fields:Array<Expr>, ?extend:String, interfaces:Array<String>, ?isFinal:Bool, ?isPrivate:Bool );
 	EEnum( en:EnumDecl, ?isAbstract:Bool );
+	ECast(e:Expr, ?t:CType);
 }
 
 @:structInit

hscript/Interp.hx

@@ -882,6 +882,8 @@ class Interp {
 				}
 
 				variables.set(en.name, enumThingy);
+			case ECast(e, _): // TODO
+				return expr(e);
 			case EConst(c):
 				switch (c) {
 					case CInt(v): return v;

hscript/Parser.hx

@@ -1146,7 +1146,22 @@ class Parser {
 			}
 			
 			mk(EEnum({ name: name, fields: fields }, false), p1);
-
+		case "cast":
+			var tk = token();
+			var e:Expr = null;
+			var t:CType = null; // null if is unsafe cast
+			switch(tk) {
+				case TPOpen:
+					e = parseExpr();
+					ensure(TComma);
+					t = parseType();
+					ensure(TPClose);
+				default:
+					push(tk);
+					e = parseExpr();
+			}
+			
+			mk(ECast(e, t));
 		case "return":
 			var tk = token();
 			push(tk);

hscript/Printer.hx

@@ -171,6 +171,16 @@ class Printer {
 
 			tabs = tabs.substr(1);
 			add("}");
+		case ECast(e, t):
+			var safe = t != null;
+			add("cast ");
+			if(safe) add("(");
+			expr(e);
+			if(safe) {
+				add(", ");
+				addType(t);
+				add(")");
+			}
 		case EConst(c):
 			switch( c ) {
 			case CInt(i): add(i);