Are there any languages targeting JavaScript (like CoffeeScript) and written in Python? I found Pyjamas, but it’s GWT of Python as I see. I want a language that doesn’t need heavy runtime library and is able to be compiled to JavaScript. I found Mascara also, and it very satisfies my requirements except it’s license. CoffeeScript is ideal for me except it’s written in CoffeeScript itself. I have to compile [CoffeeScript-like language] source codes into JavaScript statically in Python application.
You might want to have a look at pyjaco (python to javascript compiler).
Here's an example to get you started with manipulating the DOM in Python using jQuery:
https://github.com/chrivers/pyjaco/tree/devel/examples/jquery
Check this:
PyvaScript: http://www.allbuttonspressed.com/blog/django/2010/07/PyvaScript-Pythonic-syntax-for-your-browser
Pyjs: https://github.com/anandology/pyjs
Pyjamas: http://pyjs.org/
One part of Pyjamas is pyjs, which is decribed this way in the project overview:
pyjs translates Python code to Javascript by walking the Python abstract syntax tree and generating Javascript.
Sounds like it should fit the bill: no need to use the other parts of pyjamas you don't need.
Related
I know that it's possible to transform avdl to series of avsc files using java tools provided by Apache.
But despite the website lists plenty of implementations on different languages too, including JS, it seems to be that there is no support for avdl -> avsc conversion in these.
What would be your recommendation how to perform this conversion in pure JavaScript? Does such library even exists or we're forced to go through pure Java implementation always?
Java seems to be the only language that they implemented the compilation from avdl to avsc. The easiest route is probably just to have the avro-tools.jar somewhere and then have your JS code call out to that in some sub process to compile the schemas.
The other option would be to re-implement the IDL compiler in JS. I wouldn't do that, but the Java implementation is pretty much all contained within https://github.com/apache/avro/blob/master/lang/java/compiler/src/main/javacc/org/apache/avro/compiler/idl/idl.jj if you wanted to take a look.
I am a little curious about how javascript frameworks work. Web development isn't really my area of expertise (I'm more of a c/c++ guy), but do javascript frameworks get translated into vanilla javascript?
Upon inspection of website source, it seems like it is mostly just standard javascript. Do these javascript engines just translate code into javascript on the server side?
Yes, most of JavaScript Frameworks translates the code you write to vanilla JavaScript, however, this does not happen on the Server Side, that would be really slow (Server side code is used to check databases, serve files, authenticate, etc.). This process of translation is done in compilation time (Although it is translation). (Just like when you compile c++ code into binary).
When it's source code to source code like JavaScript and React (JSX) to Vanilla JavaScript (JS), it's translation. When it's source code to binary like C++ source code to an executable (.exe) is compilation.
After you're done writting your JavaScript code with frameworks, you most translate it to Vanilla JavaScript (if you also used other uncommon languages to write styles, you must translate them too, like SASS instead of CSS). It is also common to minify it, so it can load faster.
All this is mainly done by tools like webpack.
When your site is up and running, we can say that is run time.
Looking at the fact that they were written in js they would be resolved to js before running and as Robin said they are executed on client side except Node which is a runtime environment and not a framework
I need to parse docstring from several python files and I need to do this with Javascript.
I couldn't find any reference for this, any ideas?
EDIT: I'm working with Titanium SDK and jquery. PyDoc is not the solution that I'm looking for because I don't want to include some process on the middle of the javascript and the python source code.
EDIT 2: SOLVED - Titanium can use python and javascript at the same time, so I can use python to parse the docstring from the python files.
Check out how the lexer of SyntaxHighlighter works. That should give you some idea on how to proceed. There are some other syntax highlighters to study as well in case this doesn't fit your purposes.
There is no "hard" enforced docstring format, but as with most of Python, only a "best practice" document. See the following PEP for the specification of how to use Docstrings and what they are, along with many Links for followup reading:
http://www.python.org/dev/peps/pep-0257/
You can also try looking at PyDoc, which is used internally by Python to display Docstrings. It can output HTML, but even if that is not sufficient, you should be able to transfer the Python source into JavaScript to write your own parser.
How do you use CoffeeScript? It need to be compiled, so - you write code in CoffeScript, compile it, and insert real JavaScript on your site?
Doesn't it take a lot of time? Or is there some another way?
P.S. I've seen another way - to insert in development stage coffeescript in text/coffeescript script-tags with coffeescript.js library (about 150k), and compile only for production version and insert real Javascript.
The answer is yes, you compile it and include the generated JavaScript on your side.
If you're using a web framework (rails, django etc) you should take a look at the following list of coffeescript plugins: https://github.com/jashkenas/coffee-script/wiki/Web-framework-plugins. They will compile your coffeescript to javascript when you deploy your app to a server.
Using the coffee-script plugin with the text/coffeescript tags is another option, gzipped and compressed, its only about 39kB, but that can add up if you include it on pages that get many hits and I don't think is a good idea when you can compile the coffeescript to javascript yourself without needing the plugin.
There is the middleman plugin which will lets you work with CoffeeScript during development, then compile and minify it for deployment.
When you are first learning coffeescript, you will almost certainly want to do your compilation manually during development, because you will probably find, as most of us do, that you need to be able to look at the javascript code in order to debug and find out what's going on. The more fluent and comfortable you become with coffescript, the less often you will need to refer to the javascript code.
I think this will probably be true no matter what your level of expertise in javascript. If you are a javascript pro, you will be dependent on looking at stuff you are familiar with, until you start to figure out how coffeescript works. On the other hand, if you are completely or partially unfamiliar with all the quirks and subtleties of javascript, such as prototypes, the javascript approach to scope and globals, and all the rest, you'll find yourself digging into javascript references, and cross-referencing the javascript code with your coffescript code, until you get familiar with it.
I know there are lots of libraries that read byte codes that are written in Java. Does someone know of a byte code library that is implemented in Javascript?
Since javascript is typically run inside a browser, it generally cannot read the actual bytes out of files, which makes it less-than-ideal for reading java bytes. If you somehow got the byte codes encoded in a form that the javascript could read, what would you expect the library to do with it? Can you provide more details about what you're trying to do?
If you're looking to be able to write code in Java, and have it run inside a browser, take a look at GWT. It uses Java to recompile your byte-code into optimized javascript.
Edit
Based on your added comment, that you are hoping to "find out the classes and methods used in a jar file on my local disk":
Since javascript is unable to access files on a local disk (at least, without using ActiveX), the technology simply won't allow for this sort of thing. Is there a reason you wanted to use javascript for this, rather than java?
And please accept my apologies if it sounded like I was questioning your motives. I really just wanted to get enough information to be able to adequately answer your question.
Update:
It looks like the Japanese project I tried to link to below is long gone.
In any case, time has passed and now there are a couple of hits for "jvm in javascript" on Google. Namely:
Doppio
BicaVM
Look what I found:
http://ejohn.org/blog/running-java-in-javascript/
Does this help?
Edit: unfortunately it looks like the original project's site is dead.
You could try through the Web Archive, here (in Japanese, tried to Google translate it, but I guess it was too much indirection :))
For goodness sake, if you follow that link, run your download through an anti-virus.
I don't know if it's trustworhty.
There are compilers which can compile Java to JavaScript. As a last resort, you can use one of those compilers to take a JVML bytecode disassembler written in Java and compile it to JavaScript. One example of such a compiler is GWT.
Similarly, there are compilers which can compile JVML bytecode to JavaScript. Again, you can take one of the above JVML bytecode disassemblers written in Java, use any Java-to-JVML compiler (javac, ecj, gcj, …) to compile it to JVML (i.e. .class files), then compile those .class files to JavaScript.