Java2dart, how use it - dart

I have downloaded the sources, then... I don't know what I'm supposed to do.
I think that we have to compile these, but I'm not really familiar with java.
Do you have a complete example for use it ?

The java2dart tool was written for Google's own use, to help convert many of the tools from Java into Dart. Is was not intended to support conversion of all Java apps; just what was required to get things like the IDE tools (Analyzer, etc.) into Dart.
As such, there's not a huge amount of info on what it can/can't do or the best way to use it. It is written in Java, and there doesn't appear to be a pre-built binary; so it would almost certainly involve compiling the Java yourself. Unfortunately I have almost zero experience with Java (or fortunately, depending on your point of view :))
You can find a little info on this in the Dart Google Group here:
https://groups.google.com/a/dartlang.org/d/msg/misc/4mSK-M7dm2U/ARbTh6emb-sJ
I wonder whether anyone has tried running java2dart on java2dart to get a nice Dart version? :) Or even then running it through dart2js to get a JavaScript version! ;)

Related

Is it possibe to write Gnome extensions in Dart and compile it to JS?

In theory it looks like it should be possible. There is: Dart-to-JavaScript compiler and even package to call JS from Dart and opposite.
But I didn't find any resources about it. Did anybody tried? Does anybody knows for sure that it is not possible?
Short answer: maybe, but I seriously doubt it's worth the effort.
To do anything useful with JavaScript, you need to write for a platform like the Web API, node.js, or GNOME in the case of GJS. Dart seems to support the Web API with its web library and its own platform with the vm library.
You might be able to write a transpiler that could transpose from a subset of Dart to GJS, but using any existing dart transpiler is probably impossible.

Evaluating Rascal's Performance?

I want to evaluate the performance of Rascal for a given rewrite system that I've written. I'm wondering if there's a good way of doing it?
Ideally, I'd generate some compiled Java classes from the system and then run them manually against my inputs. Is there an easy or recommended way to do it?
Cheers,
One way to do this is to use the functions in the library util::Benchmark. Typically, you could write something like
cpuType( (){ call_the_function_I_want_to_observe(); } ). This will execute your function and print the cpu time used.
Note that Rascal can be executed in two ways: interpreted and compiled which makes a big difference when measuring performance. We are working hard at the moment to fully integrate the compiler in the Eclipse IDE, but a stand alone version is available as well. This can be called as java -Xss8m -jar rascal-0.8.4-SNAPSHOT.jar --compiledREPL followed by at least values for directories for sources (--src), and binaries (--bin). Here rascal-0.8.4-SNAPSHOT.jar (but most likely named differently) is downloaded from the https://update.rascal-mpl.org/console/rascal-shell-unstable.jar.
If you need more information, don't hesitate to ask for more details: this part of our tool chain is unfortunately still undocumented.

Signal Processing Algorithm Psola or Wsola in Delphi

I'm trying a long-time to find algorithm PSOLA (Pitch Synchronous Overlap Add) or WSOLA (Waveform Similarity Overlap Add) which are Acoustic or Signal Processing Algorithms.
I found it in c++, but I have no experience in c++ and is difficult to pass it to Pascal. Anyone have this code in Pascal or know where to find it to copy?
Something like this example that is in c++
http://sourceforge.net/projects/mffmtimescale/files/v3%20stable/v3.9/WSOLA.v.3.9.zip/download?use_mirror=ufpr
Try the SoundTouch DLL, it comes with a Delphi import unit, so you can use the DLL directly. It should not be too hard to compile it. Just download the free VC++ Express from the MS download site and compile it with that or ask someone with VC++ to compile it for you.
FWIW, who knows, with a few modifications, it might also compile with C++Builder.
About one decade ago, I've used praat in FSeqEdit (Delphi program) to do these type of calculations, but I think the same approach would still work fine today.
I wrote some praat-scripts and execute them via praatcons.exe (console version of praat). You can download the console version from this page:
http://www.fon.hum.uva.nl/praat/download_win.html
That works pretty good.
I usually take this approach:
I manually check what type of conversions and calculations need to be done via the GUI version of praat. Once I find what I need, I create a script for it, and run that with the console version.
Praat is very powerful, so if you didn't know about it yet, make sure to check it out.
There's a page that shows how to work with PSOLA resynthesis here:
http://www.ling.ohio-state.edu/~kyoon/praat-tut/praat-tut2.html
Let me know if you want to see some example code on how to integrate it into your Delphi application (it's pretty straightforward actually).

Starting Lua, what to use?

I'm trying to learn Lua, but I don't really know which binary to download. There's 2 choices:
Lua Binaries
Lua for Windows
The second option Lua for Windows seems to be the recommended option, but the installer weighs in at 26.6Mb, which is pretty hefty for what is supposed to be a v.lightweight language.
I'm thinking of using Lua as a scripting language for games, and perhaps as a fast development language for file processing like how Python or Ruby does it. So it must be something lightweight, not a 26.6Mb file.
Which is the appropriate one to download and start?
Luaforwindows, no doubt. It's simpler, easier and faster.
The installer comes with lots of stuff (Scite editor & several extra libs if I remember well). But the installer asks you before installing all those extra stuff. Just install the minimum and you will be fine.
Lua for Windows includes a handful of other, useful libraries and tools. The actual Lua executable included is still tiny, in the 1-2MB range as expected.
Having the extras there already will only make things easier, and disk space is cheap: go with Lua for Windows.
You may also want to check ZeroBrane Studio, which is only 4M download on Windows and is based on the same editor as SciTE that comes with Lua for Windows. ZBS also comes with 50+ Lua examples and few simple lessons to get started quickly with Lua programming.
Quoting from here.
Installation
The LuaBinaries files are intended for advanced users and programmers who want to incorporate Lua in their applications or distributions and would like to keep compatibility with LuaBinaries, so they also will be compatible with many other modules available on the Internet.
If what you want is a full Lua installation, please check other projects such as the Lua for Windows and LuaRocks.
Seems quite clear to me that you should download Lua for Windows.

Firefox extension: native code execution?

Is it possible to write an extension that runs native, platform-dependent code? I'm an extension-newbie (what a phrase!) :), can you please point me towards good material on this subject? (good keywords to feed to Google are enough)
(I would like to put a GtkMenu in Firefox)
Edit:
I started checking out the Gecko SDK, and it's a rather big subject, and I'm not sure this is what I want.
I'd be happy with a friendly manual (which is not a raw reference, but rather some kind of tutorial on how to make extensions that utilize XPCOM (if that is the way). Good keywords are still appreciated.
Check out the Gecko SDK.
You can use it make portable C++ native code firefox extensions which I believe are XPCOM objects with JavaScript wrappers in the .xpm zip file.
I haven't tried it, but you can go the usual route and write the plugin, I mean extension, in javascript also.
Native Client doesn't quite offer the breadths of API firefox extensions offer, but it's still well worth checking out for your purposes IMHO.
Yes, you can. Witness the Cooliris extension, that makes (heavy) use of your 3D graphics card, and is Windows specific.

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