What are some good resources/examples for good coding patterns to follow in RShiny applications?
I feel I am following two bad patterns in the shiny applications I am creating.
To make things react to user changes properly, I seem to end up wrapping most parts of server.r in observe().
At the beginning of each observe(), I want the expression to rerun if any one of a whole bunch of inputs change.
Ideally, I would like to put input[change_set] where change_set is a character vector of input names, however this gives an error of Error in [.reactivevalues: Single-bracket indexing of reactivevalues object is not allowed.
(or if I use input[[change_set]]: Error in checkName: Must use single string to index into reactivevalues)
What I end up doing to make things work is including multiple lines of input$var1, input$var2, ..., input$var15. This feels very wrong.
I am not making use of any functions like: reactive(), reactiveValues(), isolate(), withReactiveDomain(), makeReactiveBinding(), ... . I am guessing that I probably should be, but I don't know how to use them.
The solution to this problem is likely to be me rereading the small print in the documentation and reading code from example applications. Does anybody know any good quality resources for this?
Related
as you can see the title explains a little.
I know several questions have alreay been asked about custom extensions, but i want also the file i'm using to be readable only from the program i'm writing, and if opened from the explorer,it would not be making any sense(maybe crypted).
The program i'm coding is a substitution cipher
in C++, and it works with two maps, so that every letter in the message would be found in one map, and substituted with the corresponding letter in the other.
I'm trying to store these 2 maps in a file, so how would you suggest i could acheive this ?
P.S: I couldn't find any similar question, If you do, please give me a link
For educational purposes, I would like to build an IDE for PHP coding.
I made a form app and added OpenFileDialog ..(my c# knowledge was useful, because it was easy ... even though without intelisense!)
Loading a file and reading lines from it is basically the same in every language (even PERL).
But my goal is to write homemade intelisense. I don't need info on the richtextBox and the events it generates, endline, EOF, etc, etc.
The problem I have is, how do I handle the data? line for line?
a struct for each line of text file?
looping all the structs in a linked list? ...
while updating the richtextBox?
searching for opening and closing brackets, variables, etc, etc
I think Microsoft stores a SQL type of database in the app project folders.
But how would you keep track of the variables and simulate them in some sort of form?
I would like to know how to handle this efficiently on dynamic text.
Having never thought this through before, it sounds like an interesting challenge.
Personally, I think you'll have to implement a lexical scanner, tokenizing the entire source file into a source tree, with each token also having information about it mapping the token to a line/character inside of the source file.
From there you can see how far you want to go with it - when someone hovers over a token, it can use the context of the code around it to be more intelligent about the "intellisense" you are providing.
Hovering over something would map back to your source tree, which (as you are building it) you would load up with any information that you want to display.
Maybe it's overkill, but it sounds like a fun project.
This sounds to be related to this question:
https://softwareengineering.stackexchange.com/questions/189471/how-do-ide-s-provide-auto-completion-instant-error-checking-and-debugging
The accepted answer of that question recommends this link which I found very interesting:
http://msdn.microsoft.com/en-us/magazine/cc163781.aspx
In a nutshell, most IDEs generate the parse tree from the code and that is what they stores and manage.
In a nutshell, I want to have different faces for some types of file in dired mode. I don't think it matters, but I am using Aquamacs.
The example I will use here is .tex files. If I can do it for .tex, then I can just apply the same structure to do create other faces for other types of files.
From what I understand, I have to create a variable, write a regular expression, then apply a hook. I read a bit about regex and so far I have
^(.+)\.tex$
I think my structure and regular expression are not really correct. I am not a programmer (though I have an interest on it), I have only been using Emacs for 2 weeks or so, so any help would be greatly appreciated.
What I need is at least the basic structure of what I have to do. I understand there may be modes already created that do something similar (such as maybe Wdired and Dired-X), and I would not complain if someone told me about them, but what I really want is to have an elisp code (either already written or that I can work on), as I plan on learning a bit of elisp to be able to write my own customisations and this would be a way to learn.
Thank you!
Since you want to learn how to do it, try checking out the extension dired+.el. This mode does a lot more than what you want, but it does add new faces. Specifically, look for the variable diredp-font-lock-keywords-1 and how it is used. That should get you going.
Other SO questions that seem relevant are:
Match regular expression as keyword in define-generic-mode
Highlighting correctly in an emacs major mode
A hello world example for a major mode in emacs?
We're in the final stages of shipping our console game. On the Wii we're having the most problems with memory of course, so we're busy hunting down sloppy coding, packing bits, and so on.
I've done a dump of memory and used strings.exe (from sysinternals) to analyze it, but it's coming up with a lot of gunk like this:
''''$$$$ %%%%
''''$$$$%%%%####&&&&
''''$$$$((((!!!!$$$$''''((((####%%%%$$$$####((((
''))++.-$$%&''))
'')*>BZf8<S]^kgu[faniwkzgukzkzkz
'',,..EDCCEEONNL
I'm more interested in strings like this:
wood_wide_end.bmp
restroom_stonewall.bmp
...which mean we're still embedding some kinds of strings that need to be converted to ID's.
So my question is: what are some good ways of finding the stuff that's likely our debug data that we can eliminate?
I can do some rx's to hack off symbols or just search for certain kinds of strings. But what I'd really like to do is get a hold of a standard dictionary file and search my strings file against that. Seems slow if I were to build a big rx with aardvaark|alimony|archetype etc. Or will that work well enough if I do a .NET compiled rx assembly for it?
Looking for other ideas about how to find stuff we want to eliminate as well. Quick and dirty solutions, don't need elegant. Thanks!
First, I'd get a good word list. This NPL page has a good list of word lists of varying sizes and sources. What I would do is build a hash table of all the words in the word list, and then test each word that is output by strings against the word list. This is pretty easy to do in Python:
import sys
dictfile = open('your-word-list')
wordlist = frozenset(word.strip() for word in dictfile)
dictfile.close()
for line in sys.stdin:
# if any word in the line is in our list, print out the whole line
for word in line.split():
if word in wordlist:
print line
break
Then use it like this:
strings myexecutable.elf | python myscript.py
However, I think you're focusing your attention in the wrong place. Eliminating debug strings has very diminishing returns. Although eliminating debugging data is a Technical Certification Requirement that Nintendo requires you to do, I don't think they'll bounce you for having a couple of extra strings in your ELF.
Use a profiler and try to identify where you're using the most memory. Chances are, there will be a way to save huge amounts of memory with little effort if you focus your energy in the right place.
This sounds like an ideal task for a quick-and-dirty script in something supporting regex's. I'd probably do something in python real quick if it was me.
Here's how I would proceed:
Every time you encounter a string (from the strings.exe output), prompt the user as to whether they'd like to remember it in the dictionary or permanently ignore it. If the user chooses to permanently ignore the string, in the future when its encountered, don't prompt the user about it and throw it away. You can optionally keep an anti-dictionary file around to remember this for future runs of your script. Build up the dictionary file and for each string keep a count or any other info about it you'd like about it. Optionally sort by the number of times the string occurs, so you can focus on the most egregious offenders.
This sounds like an ideal task for learning a scripting language. I wouldn't bother messing with C#/C++ or anything real fancy to implement this.
I will first describe the problem and then what I currently look at, in terms of libraries.
In my application, we have a set of variables that are always available. For example: TOTAL_ITEMS, PRICE, CONTRACTS, ETC (we have around 15 of them). A clients of the application would like to have certain calculations performed and displayed, using those variables. Up until now, I have been constantly adding those calculations to the app. It's pain in the butt, and I would like to make it more generic by way of creating a template, where the user can specify a set of formulas that the application will parse and calculate.
Here is one case:
total_cost = CONTRACTS*PRICE*TOTAL_ITEMS
So, want to do something like that for the user to define in the template file:
total_cost = CONTRACTS*PRICE*TOTAL_ITEMS and some meta-date, like screen to display it on. Hence they will be specifying the formula with a screen. And the file will contain many formulas of this nature.
Right now, I am looking at two libraies: Spirit and matheval
Would anyone make recommendations what's better for this task, as well as references, examples, links?
Please let me know if the question is unclear, and I will try to further clarify it .
Thanks,
Sasha
If you have a fixed number of variables it may be a bit overkill to invoke a parser. Though Spirit is cool and I've been wanting to use it in a project.
I would probably just tokenize the string, make a map of your variables keyed by name (assuming all your variables are ints):
map<const char*,int*> vars;
vars["CONTRACTS"] = &contracts;
...
Then use a simple postfix calculator function to do the actual math.
Edit:
Looking at MathEval, it seems to do exactly what you want; set variables and evaluate mathematical functions using those variables. I'm not sure why you would want to create a solution at the level of a syntax parser. Do you have any requirements that MathEval does not fulfill?
Looks like it shouldn't be too hard to generate a simple parser using yacc and bison and integrate it into your code.
I don't know about matheval, but boost::spirit can do that for you pretty efficiently : see there.
If you're into template metaprogramming, you may want to have a look into Boost::Proto, but it will take some time to get started using it.