[es7] implement exponentiation operator proposal

test/webkit/fast/js/parser-syntax-check-expected.txt

Index: test/webkit/fast/js/parser-syntax-check-expected.txt
diff --git a/test/webkit/fast/js/parser-syntax-check-expected.txt b/test/webkit/fast/js/parser-syntax-check-expected.txt
index 132fb4bca0ad802b44aae4432cdb14102a5f0fed..cdce74f559c83a56dc9aa498a970aacc4a5c1bf6 100644
--- a/test/webkit/fast/js/parser-syntax-check-expected.txt
+++ b/test/webkit/fast/js/parser-syntax-check-expected.txt
@@ -57,8 +57,8 @@ PASS Invalid: "a-- ++"
 PASS Invalid: "function f() { a-- ++ }"
 PASS Invalid: "(a:) --b"
 PASS Invalid: "function f() { (a:) --b }"
-PASS Valid:   "++ -- ++ a"
-PASS Valid:   "function f() { ++ -- ++ a }"
+FAIL Valid:   "++ -- ++ a" should NOT throw 
+FAIL Valid:   "function f() { ++ -- ++ a }" should NOT throw 

[caitp (gmail), 2016/02/08 22:09:44]

The grammar change in the latest version of the proposal might be a bit
dangerous because of these ReferenceErrors becoming early errors /cc rwaldron
(but I assume people have been okay with this so far?)

[caitp (gmail), 2016/02/09 23:09:09]

In implementations today, it's a ReferenceError at runtime, rather than a
SyntaxError (although it might actually just be an early ReferenceError)

[Dan Ehrenberg, 2016/02/11 08:16:50]

Yeah, good to call this out as dangerous. Let's do this change in another patch.
We have other things that the spec says should be SyntaxErrors, but we currently
make errors at runtime; maybe they should be changed, but it'd be good to
collect some more data before shipping. Shouldn't be too hard to add a
UseCounter (as I recently did for for-in-initializer), should it?

 PASS Valid:   "++ new new a ++"
 PASS Valid:   "function f() { ++ new new a ++ }"
 PASS Valid:   "delete void 0"
@@ -67,10 +67,10 @@ PASS Invalid: "delete the void"
 PASS Invalid: "function f() { delete the void }"
 PASS Invalid: "(a++"
 PASS Invalid: "function f() { (a++ }"
-PASS Valid:   "++a--"
-PASS Valid:   "function f() { ++a-- }"
-PASS Valid:   "++((a))--"
-PASS Valid:   "function f() { ++((a))-- }"
+FAIL Valid:   "++a--" should NOT throw 
+FAIL Valid:   "function f() { ++a-- }" should NOT throw 
+FAIL Valid:   "++((a))--" should NOT throw 
+FAIL Valid:   "function f() { ++((a))-- }" should NOT throw 
 PASS Valid:   "(a.x++)++"
 PASS Valid:   "function f() { (a.x++)++ }"
 PASS Invalid: "1: null"
@@ -325,16 +325,16 @@ PASS Invalid: "function f() { throw }"
 var and const statements
 PASS Valid:   "var a, b = null"
 PASS Valid:   "function f() { var a, b = null }"
-FAIL Valid:   "const a = 5, b, c" should NOT throw
-FAIL Valid:   "function f() { const a = 5, b, c }" should NOT throw
+FAIL Valid:   "const a = 5, b, c" should NOT throw 
+FAIL Valid:   "function f() { const a = 5, b, c }" should NOT throw 
 PASS Invalid: "var"
 PASS Invalid: "function f() { var }"
 PASS Invalid: "var = 7"
 PASS Invalid: "function f() { var = 7 }"
 PASS Invalid: "var c (6)"
 PASS Invalid: "function f() { var c (6) }"
-FAIL Valid:   "if (a) var a,b; else const b, c" should NOT throw
-FAIL Valid:   "function f() { if (a) var a,b; else const b, c }" should NOT throw
+FAIL Valid:   "if (a) var a,b; else const b, c" should NOT throw 
+FAIL Valid:   "function f() { if (a) var a,b; else const b, c }" should NOT throw 
 PASS Invalid: "var 5 = 6"
 PASS Invalid: "function f() { var 5 = 6 }"
 PASS Valid:   "while (0) var a, b, c=6, d, e, f=5*6, g=f*h, h"
@@ -343,8 +343,8 @@ PASS Invalid: "var a = if (b) { c }"
 PASS Invalid: "function f() { var a = if (b) { c } }"
 PASS Invalid: "var a = var b"
 PASS Invalid: "function f() { var a = var b }"
-FAIL Valid:   "const a = b += c, a, a, a = (b - f())" should NOT throw
-FAIL Valid:   "function f() { const a = b += c, a, a, a = (b - f()) }" should NOT throw
+FAIL Valid:   "const a = b += c, a, a, a = (b - f())" should NOT throw 
+FAIL Valid:   "function f() { const a = b += c, a, a, a = (b - f()) }" should NOT throw 
 PASS Invalid: "var a %= b | 5"
 PASS Invalid: "function f() { var a %= b | 5 }"
 PASS Invalid: "var (a) = 5"
@@ -472,8 +472,8 @@ PASS Invalid: "for (var a = (b in c in d) break"
 PASS Invalid: "function f() { for (var a = (b in c in d) break }"
 PASS Invalid: "for (var (a) in b) { }"
 PASS Invalid: "function f() { for (var (a) in b) { } }"
-PASS Valid:   "for (var a = 7, b = c < d >= d ; f()[6]++ ; --i()[1]++ ) {}"
-PASS Valid:   "function f() { for (var a = 7, b = c < d >= d ; f()[6]++ ; --i()[1]++ ) {} }"
+FAIL Valid:   "for (var a = 7, b = c < d >= d ; f()[6]++ ; --i()[1]++ ) {}" should NOT throw 
+FAIL Valid:   "function f() { for (var a = 7, b = c < d >= d ; f()[6]++ ; --i()[1]++ ) {} }" should NOT throw 
 try statement
 PASS Invalid: "try { break } catch(e) {}"
 PASS Invalid: "function f() { try { break } catch(e) {} }"