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Why we need Python in the Browser

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Re: Why we need Python in the Browser

#61

Post by jamesgeck0 »

tomp wrote: post #23

Python in the browser would ultimately lead to all the same problems as Javascript in the browser. In a few years, we'll be hearing: Clojure in the browser, Scala in the browser, Haskell in the browser. I've been programming in Python full-time for the past 6 months, and it's main deficiency are the same as JavaScript's: no (optional) static typing - I'm really sick of writing checks whether my function got values of…

> I'm really sick of writing checks whether my function got values of the correct types

That doesn't sound like a problem that you should be having. The "Pythonic" way to do things is just roll with the values you get and handle any errors that result.

Re: Why we need Python in the Browser

#62

Post by scriptproof »

With a tool like Enyo you can write all the code in a sort of JavaScript, and it is converted to HTML + JavaScript. Google also has a tool to convert Java to JavaScript. Why not a similar tool for Python (or other language)? No practical need to have a lot of languages in the browser itself IMHO even if it would be nice to program web pages with his favorite language.

Re: Why we need Python in the Browser

#64

Post by tomp »

mhansen wrote: post #56
tomp wrote: post #23

Python in the browser would ultimately lead to all the same problems as Javascript in the browser. In a few years, we'll be hearing: Clojure in the browser, Scala in the browser, Haskell in the browser. I've been programming in Python full-time for the past 6 months, and it's main deficiency are the same as JavaScript's: no (optional) static typing - I'm really sick of writing checks whether my function got values of…

FYI, Dart does type checking. If you want to give your javascript some type-checking, try running it through the closure compiler. This is what we do, and we annotate our methods with type signatures like this /** * Queries a Baz for items. * @param {number} groupNum Subgroup id to query. * @param {string|number|null} term An itemName, * or itemId, or null to search everything. */ goog.Baz.prototype.query = function(…

> FYI, Dart does type checking.

According to the official docs [1], it does not: They have no effect whatsoever in production mode.

Dart does, indeed, have a "checked mode" in which types are checked (I wasn't aware of that before).

In any case, Dart's type system is inconsistent (like Java's), intentionally, but I still don't think I could be called "static".

[1] https://docs.google.com/document/pub?id=1RqcfL64kw5SJkyut6eN...

Re: Why we need Python in the Browser

#65

Post by Pewpewarrows »

tomp wrote: post #23

Python in the browser would ultimately lead to all the same problems as Javascript in the browser. In a few years, we'll be hearing: Clojure in the browser, Scala in the browser, Haskell in the browser. I've been programming in Python full-time for the past 6 months, and it's main deficiency are the same as JavaScript's: no (optional) static typing - I'm really sick of writing checks whether my function got values of…

> I'm really sick of writing checks whether my function got values of the correct types, and unittests testing if a class's/function's signature changed in an unexpected way.

Sorry to be blunt, but if every one of your Python functions and methods begins with isinstance() checks for every parameter, you just missed the point of the entire language. Python was built on a foundation of ducktyping, with the mantra that "it's easier to ask forgiveness than permission" (EAFP).

Just use your parameters in whatever way you expect them to be, and either catch the rare Exception there or allow them to bubble up. Here's some suggested reading on the subject:

http://www.canonical.org/~kragen/isinstance/

http://stackoverflow.com/questions/6092992/why-is-it-easier-...

Re: Why we need Python in the Browser

#66

Post by Yaggo »

mhansen wrote: post #59

This is ridiculous. I love python, but it has no language support for an event loop, and if you put it in a browser, everything would have to be done in an event loop. It'd be ugly. Javascript excels at evented programming. Use the right tool for the job.

I was just going to comment that at least Python has yield (generators) which helps to avoid callback spaghetti¹, but Javascript seems to have got it too in 1.7².

[1] http://www.tornadoweb.org/documentation/gen.html

[2] https://developer.mozilla.org/en/New_in_JavaScript_1.7#Gener...

Re: Why we need Python in the Browser

#67

Post by hannes2000 »

ttt_ wrote: post #24
hannes2000 wrote: post #12

Earlier quoted context omitted.

Lots of essential Python features are not part of the language, but belong to its standard library. The thing that makes JavaScript so portable is that it basically has no such thing (except maybe Date and Math). So to make convenient use of Python in the browser (or even to be able to run currently existing Python code), you wouldn't just have to embed the interpreter – you would have to ship this huge library. And…

You also would not be able to minify it properly because of whitespace identation constraints. Or am I off on this?

Or you could deliver your JSVM bytecode as binary files (which reveals a new set of drawbacks)

Re: Why we need Python in the Browser

#68

Post by vilya »

Drakim wrote: post #11
hetman wrote: post #7

For some time now I've been wondering why the primary scripting format consumed by browsers is JavaScript (a language intended for humans) and not some sort of standard bytecode that would be executed in a browser's virtual machine. What we need is the JSVM! In other words, something like the JVM but adapted for the browser. That probably means it would have a more dynamic typing focus since it makes sense for JavaSc…

I'm sure we could have some sort of JSVM, we could even have some sort of bytecode for the HTML, but it would destroy part of what makes the web so great: it's openness. The ability to view the source of any webpage, and even make chances and enhance it locally. There is also the fact that certain optimization can only be done by the browser if it has the actual source code rather than the compiled bytecode.

I think you're arguing a bit of a strawman when you mention viewing page sources: the discussion is about replacing JavaScript, not HTML. In any case, the fact that (non-web) applications are compiled into binaries hasn't stopped open source from flourishing.

Re: Why we need Python in the Browser

#69

Post by gbog »

ma2rten wrote: post #49
tomp wrote: post #23

Python in the browser would ultimately lead to all the same problems as Javascript in the browser. In a few years, we'll be hearing: Clojure in the browser, Scala in the browser, Haskell in the browser. I've been programming in Python full-time for the past 6 months, and it's main deficiency are the same as JavaScript's: no (optional) static typing - I'm really sick of writing checks whether my function got values of…

I also prefer typed languages. I also don't like, the way classes are implemented in Python (the whole self thing). But I think Python has enough good stuff to make up for it. To a degree this is psychological, if you only focus on the bad stuff, you will end up hating every programming language you work with.

The self thing is one of my favourite feature in python, it is then shoo easy to refactor a method in a function, it makes very clear where things come from, etc.

Re: Why we need Python in the Browser

#70

Post by hetman »

MatthewPhillips wrote: post #25
dhconnelly wrote: post #18

Earlier quoted context omitted.

Sorry, but this is not good enough. This argument is made all the time, but all you're really saying is that every other language should be a second-class citizen to JavaScript. Emscripten is a cool technical hack, but why the fuck is it 2012 and we have to compile C++ to JavaScript?

Browsers supporting JavaScript and some other bytecode format would bring web innovation to a crawl. I think once browsers are able to debug in the originating languages people will stop complaining about this.

Can you provide some reasoning for why this is necessarily the case?
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