PyPy.js: A fast, compliant Python implementation for the web

Post by Retr0spectrum » Wed, May 06, 2015, 10:15 AM UTC

fragmede wrote: post #59

Retr0spectrum wrote: post #47

Earlier quoted context omitted.

Just playing around: import js c = js.globals.document.createElement("canvas") js.globals.document.body.appendChild(c) ctx = c.getContext("2d") ctx.fillRect(10, 10, 10, 10) Edit: Here is a simple animation: import js import math import time c = js.globals.document.createElement("canvas") js.globals.document.body.appendChild(c) ctx = c.getContext("2d") def render(): ctx.clearRect(0, 0, c.width, c.height) t = time.time…

Sadly, if I paste that in, I get: >>> import js ... c = js.globals.document.createElement("canvas") ... debug: OperationError: debug: operror-type: SyntaxError debug: operror-value: ('EOL while scanning string literal', ('c callback', 1, 12, "r = c.push('import js\n", 0)) debug: OperationError: debug: operror-type: KeyError debug: operror-value: 'r' And then the input window hangs. Strangely enough, if I type it in i…

Post by throwaway41597 » Wed, May 06, 2015, 10:32 AM UTC

icebraining wrote: post #60

throwaway41597 wrote: post #55

Earlier quoted context omitted.

Since PyPy compiles RPython to C, couldn't one write a web app in RPython, compile it to C, then to JS (with asm.js) and enjoy a quick page load and smaller file size? By the way, is RPython a nice language to program in?

The differences are described here: https://rpython.readthedocs.org/en/latest/rpython.html

Post by Veedrac » Wed, May 06, 2015, 10:40 AM UTC

estomagordo wrote: post #21

Unfortunately, this is of little use to me. Why? Well, with my Swedish keyboard layout, some alt-combinations are crucial (mainly square brackets, []). And these keypresses do not seem to work.

Post by jychang » Wed, May 06, 2015, 11:03 AM UTC

fijal wrote: post #5

bayesianhorse wrote: post #3

Besides the big download size, it does several things very "right": Full Python data model, access to the full javascript model (albeit slowly currently). Also PyPy is the right choice as the basis for this (as opposed to CPython) because its ecosystem is generally more "pure" Python than CPython's. C Extensions would only get in the way.

it's systematically translating the PyPy interpreter to the Javascript, so it has to get semantics right. However I'm not sure if the drawbacks can be addressed in the current JS model, notably: very slow warmup, huge download size (that's primarily PyPy fault though), the lack of good JS access.

Post by detaro » Wed, May 06, 2015, 11:18 AM UTC

throwaway41597 wrote: post #63

icebraining wrote: post #60

Earlier quoted context omitted.

The differences are described here: https://rpython.readthedocs.org/en/latest/rpython.html

Thanks but to be honest, I'm not proficient in Python, so it's hard to guess if those restrictions would hurt, although they seem fairly small. I was more asking for personnal opinions and projects using it. I wasn't able to quickly find any, it even seems pretty much nobody writes RPython code or maybe people call it Python code so googling is hard.