Fixed parser error in x ~~~ q.

com.oracle.truffle.r.parser/src/com/oracle/truffle/r/parser/R.g

@@ -408,7 +408,7 @@ tilde_expr returns [T v]
     ;
 
 utilde_expr returns [T v]
-    : op=TILDE n_ l=or_expr { $v = builder.call(src($op, last()), operator($op), $l.v); }
+    : op=TILDE n_ l=utilde_expr { $v = builder.call(src($op, last()), operator($op), $l.v); }
     | l=or_expr             { $v = $l.v; }
     ;
 

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/ExpectedTestOutput.test

@@ -76255,6 +76255,98 @@ Error in tempfile(integer()) : invalid filename pattern
 #x ~ y + z
 x ~ y + z
+##com.oracle.truffle.r.test.builtins.TestBuiltin_tilde.testTildeDirect#
+#y <- x ~ q; str(y); list(y[[1]], y[[2]], y[[3]])
+Class 'formula'  language x ~ q
+  ..- attr(*, ".Environment")=<environment: R_GlobalEnv>
+[[1]]
+`~`
+
+[[2]]
+x
+
+[[3]]
+q
+
+
+##com.oracle.truffle.r.test.builtins.TestBuiltin_tilde.testTildeDirect#
+#y <- x ~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]])
+Class 'formula'  language x ~ ~q
+  ..- attr(*, ".Environment")=<environment: R_GlobalEnv>
+[[1]]
+`~`
+
+[[2]]
+x
+
+[[3]]
+~q
+
+[[4]]
+`~`
+
+[[5]]
+q
+
+
+##com.oracle.truffle.r.test.builtins.TestBuiltin_tilde.testTildeDirect#
+#y <- x ~~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]], y[[3]][[2]][[1]], y[[3]][[2]][[2]])
+Class 'formula'  language x ~ ~~q
+  ..- attr(*, ".Environment")=<environment: R_GlobalEnv>
+[[1]]
+`~`
+
+[[2]]
+x
+
+[[3]]
+~~q
+
+[[4]]
+`~`
+
+[[5]]
+~q
+
+[[6]]
+`~`
+
+[[7]]
+q
+
+
+##com.oracle.truffle.r.test.builtins.TestBuiltin_tilde.testTildeDirect#
+#y <- x ~~~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]], y[[3]][[2]][[1]], y[[3]][[2]][[2]], y[[3]][[2]][[2]][[1]], y[[3]][[2]][[2]][[2]])
+Class 'formula'  language x ~ ~~~q
+  ..- attr(*, ".Environment")=<environment: R_GlobalEnv>
+[[1]]
+`~`
+
+[[2]]
+x
+
+[[3]]
+~~~q
+
+[[4]]
+`~`
+
+[[5]]
+~~q
+
+[[6]]
+`~`
+
+[[7]]
+~q
+
+[[8]]
+`~`
+
+[[9]]
+q
+
+
 ##com.oracle.truffle.r.test.builtins.TestBuiltin_tilde.testTildeDirect#
 #y ~ 0 + x
 y ~ 0 + x

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_tilde.java

@@ -32,6 +32,10 @@ public class TestBuiltin_tilde extends TestBase {
 
     @Test
     public void testTildeDirect() {
+        assertEval("y <- x ~ q; str(y); list(y[[1]], y[[2]], y[[3]])");
+        assertEval("y <- x ~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]])");
+        assertEval("y <- x ~~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]], y[[3]][[2]][[1]], y[[3]][[2]][[2]])");
+        assertEval("y <- x ~~~~ q; str(y); list(y[[1]], y[[2]], y[[3]], y[[3]][[1]], y[[3]][[2]], y[[3]][[2]][[1]], y[[3]][[2]][[2]], y[[3]][[2]][[2]][[1]], y[[3]][[2]][[2]][[2]])");
         assertEval("~ x + y");
         assertEval("x ~ y + z");
         assertEval("y ~ 0 + x");