LibJS: Implement unary plus / minus

Libraries/LibJS/Tests/to-number-basic.js

@@ -1,31 +1,43 @@
 function assert(x) { if (!x) throw 1; }
 
-// FIXME: Just "+x" doesn't parse currently,
-// so we use "x - 0", which is effectively the same.
-// "0 + x" would _not_ work in all cases.
-function n(x) { return x - 0; }
-
 try {
-    assert(n(false) === 0);
-    assert(n(true) === 1);
-    assert(n(null) === 0);
-    assert(n([]) === 0);
-    assert(n([[[[[]]]]]) === 0);
-    assert(n([[[[[42]]]]]) === 42);
-    assert(n("") === 0);
-    assert(n("42") === 42);
-    assert(n(42) === 42);
+    assert(+false === 0);
+    assert(-false === 0);
+    assert(+true === 1);
+    assert(-true === -1);
+    assert(+null === 0);
+    assert(-null === 0);
+    assert(+[] === 0);
+    assert(-[] === 0);
+    assert(+[[[[[]]]]] === 0);
+    assert(-[[[[[]]]]] === 0);
+    assert(+[[[[[42]]]]] === 42);
+    assert(-[[[[[42]]]]] === -42);
+    assert(+"" === 0);
+    assert(-"" === 0);
+    assert(+"42" === 42);
+    assert(-"42" === -42);
+    assert(+42 === 42);
+    assert(-42 === -42);
     // FIXME: returns NaN
-    // assert(n("1.23") === 1.23)
+    // assert(+"1.23" === 1.23)
+    // assert(-"1.23" === -1.23)
     // FIXME: chokes on ASSERT
-    // assert(n(1.23) === 1.23);
+    // assert(+1.23 === 1.23);
+    // assert(-1.23 === -1.23);
 
-    assert(isNaN(n(undefined)));
-    assert(isNaN(n({})));
-    assert(isNaN(n({a: 1})));
-    assert(isNaN(n([1, 2, 3])));
-    assert(isNaN(n([[[["foo"]]]])));
-    assert(isNaN(n("foo")));
+    assert(isNaN(+undefined));
+    assert(isNaN(-undefined));
+    assert(isNaN(+{}));
+    assert(isNaN(-{}));
+    assert(isNaN(+{a: 1}));
+    assert(isNaN(-{a: 1}));
+    assert(isNaN(+[1, 2, 3]));
+    assert(isNaN(-[1, 2, 3]));
+    assert(isNaN(+[[[["foo"]]]]));
+    assert(isNaN(-[[[["foo"]]]]));
+    assert(isNaN(+"foo"));
+    assert(isNaN(-"foo"));
 
     console.log("PASS");
 } catch (e) {