Well, before I start arguing with you, I'd like to know what argument you're making. ;-)
Are you saying we should go back to having a MIME-type (and/or pragma) opt-in? Your subject line suggests that. Or are you saying we should simply not support some of the new features in non-strict code? Because your points only seem to be arguing for the latter, not the former. I think the MIME type idea, while obviously attractive for our purposes, would've had terrible consequences for programmers, and I really hope we don't have to relitigate that debate. Dave On Dec 26, 2012, at 2:03 PM, Mark S. Miller <[email protected]> wrote: > Hi Brian, thanks for accumulating this data! > > Between > * this data, > * Apple's decision as recorded at > <https://bugs.webkit.org/show_bug.cgi?id=27226#c4>, > * the new function syntax micro-modes, > * and the "let" issues already discussed, > I reiterate that we should stop trying to twist the language to > somehow shoehorn ES6 features into non-strict mode. > > For both "function" and "let", when we first discussed trying to > retrofit sense into ES6 non-strict mode, we knew that this was > speculative, because non-strict mode cannot include web-breaking > incompatible changes. This experiment has failed, so we should now > return to plan A. Any ES6 features that don't fit into non-strict mode > without contortion, including "let" and nested "function", should be > available only in strict mode. For new function syntax, if > shoe-horning it into non-strict mode requires micro-modes as > previously discussed, then we shouldn't. Whatever the complaints about > living with one mode distinction, we're certainly not addressing these > complaints by introducing more mode distinctions. > > > > On Wed, Dec 26, 2012 at 1:04 PM, Brian Terlson > <[email protected]> wrote: >> I have some data on patterns and sites that may break due to the proposed >> change to semantics of function decls in block scope. I am not advocating >> for any changes here but merely dumping some data I’ve gathered. I will >> continue gathering data about this breaking change and potentially others >> (eg. let[x] = 1), so any further data you folks are interested in let me >> know. I think the January meeting would be a good venue to discuss any of >> this in detail if warranted. >> >> On December 17th, 2235 sites were crawled and their scripts downloaded. >> These scripts were then processed in an attempt to identify likely breakages >> due to the change to the semantics of func decls in block scope. In this >> dataset, 4% of the scripts contained a function declaration in block scope >> (mostly inside if and try, although pretty much every node contains a >> function somewhere in this dataset). However, most of these scripts use the >> function within the same block and so won’t be broken. 20 sites, however, >> will likely be broken by this change in some way. There is also a chance >> that the tool used to identify breakages has missed some code that will >> breka. >> >> >> >> Below are some examples of code on the web today that will be broken. For >> each I include a snippet of code that is heavily edited in an attempt to >> convey the pattern used and the developer intent. I also attempt to identify >> what functionality will actually be broken. >> >> >> >> Most of the breakages occur in non-library code, with two exceptions: qTip >> 1.0, and thickbox 3. >> >> >> >> # http://ninemsn.com.au >> >> >> >> RenderModal = function () { >> >> if (x) { // is an array of shortcuts that can be added. Is statically >> non-empty. >> >> function K() { >> >> // process the array of shortcuts in some way >> >> } >> >> } >> >> K(); >> >> }; >> >> >> >> ## Scenario >> >> >> >> 1. Navigate to main page. >> >> 2. Click “Add other shortcuts” >> >> 3. Click “View more shortcuts” – this will not work. >> >> >> >> >> >> # http://yandex.ru >> >> >> >> if (_ycssjs("BaH0Fmmo2Sg24lRmTPrK0B8qpaA")) { >> >> function cp(g, c, d) { /* ...*/ } >> >> >> >> function csh_ifgsid(c, b) { /*...*/ } } >> >> >> >> // ... thousands of lines of code ... >> >> >> >> >> >> if (_ycssjs("rO+QIoSf2L0NwDn6vjJjy+27nxI")) { >> >> function news() { >> >> csh_if_gsid(); >> >> } >> >> } >> >> >> >> if (_ycssjs("YRPF0QVjJmhRiKRu6cvi3YXqYo8")) { >> >> // ... bunch of stuff ... >> >> cp(); >> >> } >> >> >> >> ## Scenario >> >> >> >> Unknown >> >> >> >> >> >> # http://g.espncdn.com/nfl-primetime-payoff/en/module/entry?matchupid=478 >> >> >> >> if (isIE && isWin) { >> >> // ... >> >> } else { >> >> function JSGetSwfVer(i){ >> >> // ... >> >> } >> >> } >> >> >> >> function checkFlash(myRev) { >> >> // ... >> >> >> >> if (isIE && isWin) { >> >> // ... >> >> } else { >> >> aV = JSGetSwfVer(rV); >> >> } >> >> >> >> } >> >> >> >> ## Scenario >> >> >> >> Can’t find a page which uses this code. >> >> >> >> >> >> # http://www.t-online.de >> >> >> >> if (!Adition_Environment) { >> >> var Adition_Environment = (function () { >> >> var _this = {}; >> >> // ... >> >> _this.getPrf = function (cuId) { >> >> var prf = ""; >> >> try { >> >> prf = Adition_Prfstr(cuId); >> >> } catch (e) { } >> >> return prf; >> >> }; >> >> // ... >> >> })(); >> >> } >> >> >> >> // snip 1k lines >> >> if (typeof Adition_Prfstr == "undefined") { >> >> function Adition_Prfstr(ADITION_CONTENTUNIT_ID) { >> >> // ... >> >> } >> >> } >> >> >> >> ## Scenario >> >> >> >> Required to display advertisements on the page. >> >> >> >> >> >> >> >> # http://manormystery.com >> >> >> >> if (!window._ate) { >> >> window._ate = { /* ... */ }; >> >> function addthis_open() { /* ... */ } } else { _ate.inst++; } >> >> >> >> if (_atc.abf) { >> >> addthis_open(document.getElementById("ab"), "emailab", >> window.addthis_url || "[URL]", window.addthis_title || "[TITLE]"); } >> >> >> >> ## Scenario >> >> >> >> Social sharing popups broken at least. This may be a general utility used in >> a number of places. >> >> >> >> >> >> >> >> # http://manhunt.net (NSFW, DO NOT VISIT AT WORK) >> >> >> >> /** @todo isFlashInstalled() should probably be gotten by include from >> js/cmmn/flashDetect.js or upfunc.js. */ >> >> >> >> if (typeof isFlashInstalled == 'undefined') { >> >> function isFlashInstalled() { >> >> var requiredMajorVersion = 6; // Major version of Flash required >> >> var requiredMinorVersion = 0; // Minor version of Flash required >> >> var requiredRevision = 0; // Minor version of Flash required >> >> var s = new SWFObject(); >> >> if (!s) return false; >> >> var version = s.installedVer; >> >> if (!version) return false; >> >> return (version.major >= requiredMajorVersion && version.minor >= >> requiredMinorVersion && version.rev >= requiredRevision); >> >> } >> >> } >> >> isFlashInstalled(); >> >> >> >> ## Scenario >> >> >> >> I avoided this site at work for obvious reasons, but it looks like all login >> functionality will be broken. >> >> >> >> >> >> >> >> >> >> # http://www.163.com >> >> >> >> NTESAD_Couplet.prototype = { >> >> NTESCreate: function () { >> >> >> >> var widthsmall = this.options.widthsmall; >> >> var width = this.options.width; >> >> >> >> if (this.options.leftbig != "" && this.options.leftsmall != "") { >> >> function bighide() { >> >> coupletLeft.style.display = "none"; >> >> coupletLeftsmall.style.display = "block"; >> >> } >> >> >> >> function smallhide() { >> >> coupletLeftsmall.style.display = "none"; >> >> coupletLeft.style.display = "block"; >> >> } >> >> } >> >> >> >> if (this.options.rightbig != "" && this.options.rightsmall != "") { >> >> function Rbighide() { >> >> coupletRight.style.display = "none"; >> >> coupletRightsmall.style.display = "block"; >> >> } >> >> } >> >> >> >> if (this.NTESPosition()) { >> >> if (this.options.leftbig != "" && this.options.leftsmall != "" >> && this.options.rightbig != "" && this.options.rightsmall != "") { >> >> this.NTESBind(coupletclose, "click", function () { >> bighide(); Rbighide(); coupletRightsmall.style.display = "none"; >> coupletLeftsmall.style.display = "none"; }); >> >> this.NTESBind(coupletclose2, "click", function () { >> bighide(); Rbighide(); coupletRightsmall.style.display = "none"; >> coupletLeftsmall.style.display = "none"; }); >> >> } >> >> } >> >> } >> >> } >> >> >> >> ## Scenario >> >> >> >> Unknown. >> >> >> >> >> >> >> >> # http://www22.verizon.com >> >> >> >> if (floatStyle.match(/Content/)) { >> >> var contentDiv = d.getElementById(_b.Preferences.Render.main_content_id >> || "content"); >> >> if (contentDiv == null) { >> >> floatStyle = this.Preferences.Render.float_style = 'fixed' >> >> } >> >> function getRightOfContent() { >> >> return contentDiv.offsetWidth + contentDiv.offsetLeft + 1 >> >> } >> >> function fixBackground() { >> >> if (_b.Preferences.Render.fix_background) { >> >> db.style.backgroundAttachment = "scroll"; >> >> var margin = null; >> >> if (document.defaultView && >> document.defaultView.getComputedStyle) { >> >> margin = >> parseInt(document.defaultView.getComputedStyle(contentDiv, >> null).getPropertyValue("margin-left"), 10) >> >> } else { >> >> margin = parseInt(contentDiv.currentStyle.marginLeft, 10) >> >> } >> >> if (isNaN(margin) || margin == 0) { >> >> margin = contentDiv.offsetLeft || 0 >> >> } >> >> db.style.backgroundPosition = (Math.floor(contentDiv.scrollWidth >> * -0.5) - 2 + margin) + 'px 0' >> >> } >> >> } >> >> } >> >> >> >> // getRightOfContent/fixBackground used repeatedly after this. >> >> >> >> ## Scenario >> >> >> >> Couldn’t find a scenario where this code was hit, but the site is expansive. >> Also, the above code is found in at least 2 different scripts across the >> site. >> >> >> >> >> >> >> >> >> >> # http://www.jeuxvideo.com >> >> >> >> if (typeof getAppNexusMegaTag == 'undefined' || typeof getAppNexusMegaTag != >> 'function') { >> >> function getSize1080667() { >> >> return '250x250'; >> >> } >> >> } >> >> >> >> if (typeof inFIF != "undefined" && inFIF == true) { >> >> try { >> >> parent.getSize1080667 = getSize1080667; >> >> } catch (e) { } >> >> } >> >> >> >> >> >> ## Scenario >> >> Ad won’t display. >> >> >> >> >> >> >> >> # http://msn.foxsports.com >> >> /* this function is much faster, so if possible we use it. Some IEs are the >> only ones I know of that need the idiotic second function, generated by an >> if clause. */ function add32(a, b) { >> >> return (a + b) & 0xFFFFFFFF; >> >> } >> >> >> >> if (md5('hello') != '5d41402abc4b2a76b9719d911017c592') { >> >> function add32(x, y) { >> >> var lsw = (x & 0xFFFF) + (y & 0xFFFF), >> >> msw = (x >> 16) + (y >> 16) + (lsw >> 16); >> >> return (msw << 16) | (lsw & 0xFFFF); >> >> } >> >> } >> >> >> >> ## Scenario >> >> >> >> Nothing is necessary broken about this, as long as the first add32 functions >> properly (today everyone with this code is using the second function). This >> is a fairly common MD5 library (do a search for “idiotic second function” to >> get an idea, however this was only found once in the dataset). >> >> >> >> >> >> >> >> >> >> >> >> # http://iwiw.hu/i/belepes >> >> >> >> (function () { >> >> if (jQuery.fn.lazyload) { >> >> function a() { >> >> return typeof f !== "undefined" ? f : (f = >> jQuery("body").hasClass("lazyloadimages")) >> >> } >> >> } >> >> jQuery(function () { >> >> if (a()) { >> >> d.apply(document.body) >> >> } >> >> }) >> >> })(); >> >> >> >> ## Scenario >> >> >> >> Unknown >> >> >> >> >> >> >> >> >> >> # http://www.laposte.net >> >> >> >> if (!window.$extend) { >> >> function $extend(c, a) { >> >> for (var b in (a || {})) { >> >> c[b] = a[b] >> >> } return c >> >> } >> >> } >> >> // $extend used repeatedly after this >> >> >> >> ## Scenario >> >> Unknown >> >> >> >> >> >> >> >> # http://atpworldtour.com >> >> >> >> /* >> >> * Stores hash values for localization. >> >> * Will need duplicating for each language. >> >> */ >> >> >> >> if (typeof registerNS == "undefined") { >> >> function registerNS(ns) { >> >> var nsParts = ns.split("."); >> >> var root = window; >> >> for (var i = 0; i < nsParts.length; i++) { >> >> if (typeof root[nsParts[i]] == "undefined") >> >> root[nsParts[i]] = new Object(); >> >> root = root[nsParts[i]]; >> >> } >> >> } >> >> } >> >> >> >> registerNS("atp.utilities"); >> >> // called repeatedly after this. >> >> >> >> ## Scenario >> >> >> >> Entire site is unusable. >> >> >> >> >> >> >> >> >> >> # http://atwiki.jp >> >> >> >> if (typeof AddClipsFlag == "undefined") { >> >> var AddClipsFlag = 'addclips'; >> >> // ... >> >> function AddClipsLoad() { /* ... */ } >> >> // ... >> >> } >> >> >> >> AddClipsLoad(); >> >> >> >> ## Scenario >> >> >> >> RSS functionality broken. This appears to be a library of some kind (see >> www.addclips.org). >> >> >> >> >> >> >> >> # Library: qTip 1.0: >> https://github.com/Craga89/qTip1/blob/master/1.0.0-rc3/jquery.qtip-1.0.0-rc3.js >> as seen on Zoompanel.com >> >> >> >> if (t.options.hide.when.event == "inactive") { >> >> function y(z) { >> >> >> >> } >> >> } else { >> >> // ... >> >> } >> >> function x(z) { >> >> if (t.options.hide.when.event == "inactive") { >> >> y() >> >> } >> >> } >> >> >> >> ## Scenario >> >> >> >> Used on zoompanel.com. Tooltips will never disappear after showing up. >> >> >> >> >> >> # Library: thickbox 3 (http://thickbox.net/), in use on runescape.com and >> baixaki.com.br if (!(TB_PrevHTML === "")) { >> >> function goPrev(){ >> >> } >> >> $("#TB_prev").click(goPrev); >> >> } >> >> >> >> if (!(TB_NextHTML === "")) { >> >> function goNext(){ >> >> } >> >> $("#TB_next").click(goNext); >> >> >> >> } >> >> >> >> document.onkeydown = function (e) { >> >> if (keycode == 190) { // display previous image >> >> if (!(TB_NextHTML == "")) { >> >> document.onkeydown = ""; >> >> goNext(); >> >> } >> >> } else if (keycode == 188) { // display next image >> >> if (!(TB_PrevHTML == "")) { >> >> document.onkeydown = ""; >> >> goPrev(); >> >> } >> >> } >> >> } >> >> >> >> ## Scenario >> >> >> >> Going back/forward with keyboard is broken. >> >> >> >> >> >> >> >> >> >> # http://kankan.com >> >> Snippet >> >> if (typeof getCookie == 'undefined') { >> >> function getCookie(name) { >> >> >> >> } >> >> } >> >> >> >> // ... >> >> >> >> if (getCookie('tpar')) { >> >> var irStartTime = new Date().getTime(); >> >> window.attachEvent('onunload', irTimeStat); } >> >> >> >> ## Scenario >> >> Unknown, possibly just for tracking purposes. >> >> >> >> >> >> # Google +1 library (only seen on TMZ.com, possibly this lib is out of date) >> try { >> >> function h(a) { >> >> throw a; >> >> } >> >> // plus a ton of other decls >> >> } catch (e) { } >> >> >> >> try { >> >> h(Error("foo")); >> >> // plus a ton of calls to other block scoped functions } catch (e) { } >> >> >> >> ## Scenario >> >> >> >> Plus one button is broken. >> >> >> >> >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> > > > > -- > Cheers, > --MarkM > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
