Question

Is there some limitation of javascript function length on Opera?

I’ve tested, how efficient solution will be to provide dictionaries as javascript function that tests what key we give and return proper values.

The advantage of that solution would be, that dictionaries would be cached without LocalStorage from HTML5, using browser cache mechanism only.

I’ve done test with address database, writing function, which fragment is here:

window.dict = {};

dict.getStreets = function (sym) {
if (sym == '46') {
    return [["Andrzeja","10028"],["B\u0142o\u0144ska","34182"],["Cisowa","10027"],["Dojazdowa","177799"],["Dolna","126726"],["Dzia\u0142kowa","153180"],["Dzikiej R\u00f3\u017cy","211051"],["Fio\u0142kowa","98636"],["Gimnazjalna","126727"],["Gwia\u017adzista","126728"],["Jana","34189"],["Jod\u0142owa","34183"],["Majowa","34184"],["Mi\u0142a","98637"],["Orzechowa","34185"],["Osiedlowa","153181"],["Polowa","34186"],["Po\u0142udniowa","98638"],["Prosta","211052"],["Purzyckiego","126729"],["R\u00f3\u017cana","211053"],["S\u0142owicza","224648"],["Spokojna","34187"],["Stra\u017cacka","98639"],["Szarotki","34188"],["\u015awierkowa","224596"],["Weso\u0142a","153182"],["Wschodnia","126730"],["Zachodnia","34190"]];
} else if (sym == '98') {
    return [["Bia\u0142ych Brz\u00f3z","177802"],["Calineczki","34192"],["Chabrowa","98640"],["Czarodziejska","98641"],["D\u0142uga","10029"],["Dworcowa","34191"],["Familijna","68666"],["Kasztanowa","153183"],["Konwaliowa","217850"],["Ko\u015bcielna","10030"],["Kr\u0119ta","34193"],["Le\u015bna","177803"],["Lipowa","153184"],["\u0141\u00f3dzka","217851"],["Malownicza","177804"],["Masztowa","217852"],["Milenijna","10031"],["P\u00f3\u0142nocna","10032"],["Przesmyk","10033"],["Romantyczna","34720"],["Skrajna","98642"],["Sosnowa","98643"],["Stokrotki","126731"],["T\u0119czowa","10034"],["Uko\u015bna","68667"],["Urocza","34721"],["Ustronna","98644"],["Zaciszna","34722"],["Zau\u0142ek","217853"]];
} else if (sym == '224') {
    return [["Maj\u0105tkowa","217854"],["Orionist\u00f3w","153185"],["Wiosenna","98645"]];
} else if (sym == '394') {
    return [["Kwiatowa","177805"],["Sochaczewska","217855"]];
} else if (sym == '460') {
    return [["Grodziska","34723"],["\u0141\u0105ki","98647"],["Nowakowskiego","217856"],["\u017buk\u00f3wka","95137"]];
// ...... about 5MB of data goes here
} else return null;
};

The whole JavaScipt has over 5MB length. This works under FireFox (very slow, as I’ve supposed), IE 9 and Chrome (quite fast), but under Opera it is not working. When I’ve limited function’s size, it works, but with full size there’s not even function getStreets set on dict object.

So I see for sure that Opera does not allow to create such big functions, as only from ‘big’ browsers. My question is, if it is somewhere documented what the limits are, or it is just some buffer overflow (or anything similar) in Opera’s javascript engine?

update
The case with dictionaries was only an inspiration that made this code to be generated. The question is about limits to the Opera javascript parser, not the other way the code above could be written

Answer 1

This is a known limitation which will soon be history: it’s got nothing to do with the size of the function, but there is a limit to the number of chained if..else if.. statements you can have. In this test and on my computer the limit is 1020 chained statements: http://jsfiddle.net/8RAn8/ but I’m not sure if this is really a static hard-coded limit or depending on some parameters. If you remove the else from the ..else if.. chaining it runs just fine: http://jsfiddle.net/8RAn8/1/ and I’ve tested more than 15000 if blocks successfully without else.

We’re about to fix this bug and change the limit to something closer to what other browsers have.