Reading dot files with graphviz package in haskell - haskell

For a program i have to reformat a dot file in Haskell to adjust the layout of its tree/content. I decided to use https://hackage.haskell.org/package/graphviz-2999.20.1.0/docs/Data-GraphViz.html , but i cant find simple tutorials and the documentation confuses me, namely:
1 . It contains a function: dotToGraph, which reads: "A pseudo-inverse to graphToDot; "pseudo" in the sense that the original node and edge labels aren't able to be reconstructed."
I do need to retain the names of the nodes and edges, which i suppose are the labels mentioned here? but it seems weird that it cannot do this. It also does not take in a file name or string for the dot text, so i assume this is the wrong function.
2 . There also seems to be a parseDot function/class that comes with the package, but i cant find clear documentation for its use. (see: https://hackage.haskell.org/package/graphviz-2999.20.1.0/docs/Data-GraphViz-Parsing.html#t:ParseDot)
Can you recommend me a simple overview/summary/online example for doing this? Should i be using a different function? I have only recently started using Haskell, so the package documentation is sometimes difficult to decipher for me.
It would help a great deal, thanks!

Related

How to use helm-semantic-or-imenu for code navigation with type annotated python code

I would like to use the helm-semantic-or-imenu command to navigate components of type annotated Python code, but whatever code analyzer is used to dentify the components doesn't seem to recognize the type annotated python code. Functions with the return type annotation doesn't get recognized at all and functions with annotated arguments show the type instead of the arguments names in the signatures
The main problem I have is that I do not properly understand the components that is involved in making this work (when it does work). Obviously it might help to somehow update the code analyzer, but in which project do I find that? helm? semantic? imenu? or as someone mentioned somewhere else with regards to code analysis python.el? I could really use some help getting started to solve this. If the code analyzer is found in python.el, can I then try to modify and make emacs use a local version preferentially over the installed one?
EDIT:
After making the initial post I finally made a break through in trying to figure out where the components come from. I searched for python*.el in all of the file systemsystem and discovered these:
./usr/share/emacs/26.2/lisp/cedet/semantic/wisent/python.elc
./usr/share/emacs/26.2/lisp/cedet/semantic/wisent/python-wy.elc
I found the source for emacs 26.2 and discovered that indeed it seems python-el is responsible for parsing python files for semantic. It also internally uses the python-wy for recognizing a large portion of the language components. But unfortunately that is where I hit a brick wall. I was hoping to be able to monkey patch the function that recognizes a function definition via an re or something, but semantic actually solves the problem the right way. So python-wy seems to be auto-generated from a formal grammar definition file (in emacs git admin/grammars/python.wy) and figuring out how to modify that it is unfortunately much beyond my abilities.
The semantic python backend doesn't appear to parse type annotations correctly (and there hasn't been much recent development on those libraries as far as I can tell). Since helm-semantic-or-imenu favors semantic when it is active, you can disable semantic altogether for python buffers unless you use its other features (personally I only use it for C/C++).
When the semantic mode-specific libraries are loaded they set imenu-create-default-create-index and imenu-default-goto-function, causing imenu to use semantic instead of python.el's imenu function.
To disable semantic support for your python files you can customize the semantic-new-buffer-setup-functions, only adding entries for modes you want semantic support for, eg. in your semantic hook (or alternatively with the customize UI),
(setq semantic-new-buffer-setup-functions
'((c-mode . semantic-default-c-setup)
(c++-mode . semantic-default-c-setup)
(srecode-template-mode . srecode-template-setup-parser)
(texinfo-mode . semantic-default-texi-setup)
;; etc.
;; (makefile-automake-mode . semantic-default-make-setup)
;; (makefile-mode . semantic-default-make-setup)
;; (makefile-gmake-mode . semantic-default-make-setup)
))

Processing insists pause() is not a function, when it very much is

Aite, [first poster here, pls don't bash]
So, I'm using the sound library, which I of course remembered to import, and works just fine, proof being given by the fact that all the other functions I used work as expected and give no problems neither in editor nor in execution.
Except, of course, for this little bugger of a pause() function, which I wrote as per below using no different a syntax from all the other functions, only to find out Processing isn't very keen on accepting its existence.
Problem shows both using 3.3.6 and 3.5.
Oh, and also, apparently isPlaying() returns an int, what's up with that?
If, as I'd suspect, that single line below won't be enough code to couple with the info to get to the bottom of it, here's a Dropbox link to the code (since it uses a bunch of files) so you can test it yourself.
It kinda won't work if you try to run it as is tho because it messes up when trying to load all the songs (in the last line of setup), yeah I kinda need some help with that too... works fine if you only load the first one tho!
https://www.dropbox.com/sh/di7mwit0w2l4513/AABipGDAdoKx277f8Hg_ZfhDa?dl=0
(Please, don't expect clear, extensively commented coding. I started working on this way before I learnt that was a thing. Deeply sorry. Of course, you can ask away about anything baffling you)
What did I try, er, writing it well???
I used .play(), .stop(), the volume ones, and they all, as per stated, work fine.
import processing.sound.*;
SoundFile[] songs= new SoundFile[1];
void setup(){
songs[0]=new SoundFile(this,"Small Bump.mp3");
songs[0].play();
}
void draw(){
}
void keyPressed(){
if (songs[0].isPlaying()==1)songs[0].pause();
}
When I copy your code into my Processing editor, I get a couple errors:
songs[0]="Small Bump.mp3";
The sounds array holds instances of SoundFile, but you're trying to store a String value here. Maybe you're looking for the SoundFile constructor?
if (songs[0].isPlaying()==1)
The isPlaying() function returns a boolean value, but you're comparing it to an int value.
songs[i].pause();
You haven't declared this i variable anywhere. Probably meant for this to be a 0.
If I fix all of these errors, then your code compiles fine.
You might want to take a look at the reference for the Sound library here.
The Sound library I had installed was 1.3.2, or something of the likes.
All the references I'd read were for 2.0+.
Having updated that through the "add library" menu, all was solved.

What is supposed to be in __init__.py

I am trying to create a Python package. You can have a look at my awful attempt here.
I have a module called imguralbum.py. It lives in a directory called ImgurAlbumDownloader which I understand is the name of the package -- in terms of what you type in an import statement, e.g.
import ImgurAlbumDownloader
My module contains two classes ImgurAlbumDownloader and ImgurAlbumException. I need to be able to use both of these classes in another module (script). However, I cannot for the life of me work out what I am supposed to put in my __init__.py file to make this so. I realize that this duplicates a lot of previously answered questions, but the advice seems very conflicting.
I still have to figure out why (I have some ideas), but this is now working:
from ImgurAlbumDownloader.imguralbum import ImgurAlbumDownloader, ImgurAlbumException
The trick was adding the package name to the module name.
It sure sounds to me like you don't actually want a package. It's OK to just use a single module, if your code just does one main thing and all its parts are closely related. Packages are useful when you have distinct parts of your code that might not all be needed at the same time, or when you have so much code that a single module would be very large and hard to find things in.

Samples and tips on using GroovyResourceLoader

I am attempting to install my own GroovyResourceLoader and was wondering if there was an authorative guide somewhere describing all hte moving bits.
Ive noticed when groovy attempts to compile a script, it does attempt to find types by sending paths to the GRL. However it does some strange things sometimes it uses '$' as a separator and other times it uses plain old '.'.
Heres a snapshot of some logging of an attempt to load something. Ignoring the auto import stuff, notice how it using '$' as the package separator and then by replacing each '$' it one at a time with a '.'.
-->a$b$groovy$X$Something
-->a.b$groovy$X$Something
-->a.b.groovy$X$Something
Im using Groovy 1.8.0.
The "$" you see come from Groovy trying to match inner classes. I strongly assume you have somewhere an "a.b.groovy.X.Something" which will lead groovy to try to discover all kinds of inner class combinations for this one. You could for example have a "a$b$groovy$X$Something.groovy" file.

haskell libmagic how to use it?

I'm trying to write a program that will check the file type of a certain file and I found a haskell library that should do the trick.
The problem arises when I try to use it. I have no idea what I have to do, which function to call etc. The library is full of cryptic commands with no examples, no tutorial or a homepage.
Please help.
There is the package's documentation that contains short descriptions of the important functions (which are not that many). For additional information about what the underlying C library does (and therefore also the Haskell library), have a look at libmagic's man page.
The basic usage should look similar to this (untested):
import Magic.Init
import Magic.Operations
main =
do magic <- magicOpen []
loadDefaultMagic magic
magicFile magic "/my/file" >>= print

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