Develop Reference

Creating Inline Functions and Macros

I know this is wrong (trying to code in C# with a C/C++ mindset).
But is it possible to create inline functions / inline recursive functions (til the Nth call) / macros in C#?
Because if I intend to call the same function 1000 times, but it's a simple function, the overhead of creating the stack is quite big... And unnecessary.
In C i could use inline functions. Is there something like that in C#?
Again... I'm not saying that C/C++ is better... I'm just new to C# and have none to ask those simple questions...

Inline functions in C#?
Finally in .NET 4.5, the CLR allows one to force1 method inlining
using MethodImplOptions.AggressiveInlining value. It is also available
in the Mono's trunk (committed today).
[MethodImplAttribute(MethodImplOptions.AggressiveInlining)]
void Func()
{
Console.WriteLine("Hello Inline");
}

The answer should be: don't worry about it. No need to start with micro-optimizations unless you've tested it and it's actually a problem. 1000 function calls is nothing until it's something. This is majorly overshadowed by a single network call. Write your program. Check the performance against the goals. If it's not performant enough, use a profiler and figure out where your problem spots are.

Yes, C# is a very powerful general purpose language that can do nearly anything. While, inline functions / macros are generally frowned upon, C# does provide you with multiple tools that can accomplish this in a more concise and precise fashion. For example, you may consider using template files which can be used (and reused) in nearly all forms of .NET applications (web, desktop, console, etc).
http://msdn.microsoft.com/en-us/data/gg558520.aspx
From the article:
What Can T4 Templates Do For Me?
By combining literal text, imperative code, and processing directives, you can transform data in your environment into buildable artifacts for your project. For example, inside a template you might write some C# or Visual Basic code to call a web service or open an Excel spreadsheet. You can use the information you retrieve from those data sources to generate code for business rules, data validation logic, or data transfer objects. The generated code is available when you compile your application.
If you're new to programming I would recommend against implementing templates. They are not easy to debug in an N-Tier application because they get generated and ran at run-time. However, it is an interesting read and opens up many possibilities.

LSODA to dll - Fortran (F77) to dll to call from C#

a little question in which I hope you can help me. (To make my life simpler)
One of the most respected numerical solvers for differential equations is LSODA, however it is written in Fortran... ( http://www.netlib.org/odepack/index.html )
There does not seem to be a decent solver for C#, and writing my own is too time consuming in C#, especially as I have very stiff equations that need to be solved.
The NAG libraries for net do not contain an ODE solver (they lack D02 routines). In terms of "university side" libraries that's it.
However NAG Support suggested calling their dll, which is fine for simple variables, but has me rather perplexed with its external functions and dummy parameters which made me give up.
This leaves LSODA still, which is fortran, but a lot simpler in its calling sequence - so I wonder, how can the Odepack (the solvers that include the lsoda routine) be turned into a dll with little work, so that it may be called from C#?
(Which will leave me worried about the Jacobian, being a matrix, i.e. 2D array.)
Specifically, I would like a situation similar to that with the Fortran NAG library, but instead offering me access to lsoda: http://www.nag.co.uk/numeric/csharpinfo.asp
Please keep in mind that I am a mathematician - so if your responses loose me, please be patient with me. And why am I so focused on C# - well, it is simple, especially when one has VisualStudio 2010.
Many thanks for any responses in advance.

SmartMathLibrary looks dead, but it claims to have ODEPACK bindings. You could also check out Wikipedia's List of .NET Numerical Packages.
If you're open to other languages, Python's SciPy library contains a binding to LSODA: enter link description here. It's available on Windows, easy to use, free, and widely embraced by the scientific community.

It's not a full solution, but f2c (Fortran-to-C converter) should be able to give you working C code from the Fortran source. That might at least be easier to get working from C#.
Disclaimer: I've never used f2c to convert a routine, I've only used some of the routines that someone else converted.

c# compile source code from database

I would like to build an application framework that is mainly interpreted.
Say that the source code would be stored in the database that could be edited by the users and always the latest version would be executed.
Can anyone give me some ideas how does one implement sth like this !
cheers,
gabor

In .Net, you can use reflection and CodeDOM to compile code on the fly. But neither approach is really very simple or practical. Mono has some ability to interpret c# on the fly as well, but I haven't looked closely at it yet.
Another alternative is to go with an interpreted .Net language like Boo or IronPython as the language for your database code.
Either way, make sure you think long and hard about the security of your platform. Allowing users to execute arbitrary code is always an exercise fraught with peril. It's often too tempting to look for a simple eval() method, and even if one exists, that is not good enough for this kind of scenario.

Try Mono ( http://www.monoproject.org ). It supports many scripting languages including JavaScript.

If you don't want to use any scripting you can use CodeDOM or Reflection (see Reflection.Emit).
Here are really useful links on the topic :
Dynamically executing code in .Net (Here you can find a tool which can be very helpul)
Late Binding and On-the-Fly Code
Generation Using Reflection in C#
Dynamic Source Code Generation and
Compilation

Usually the Program uses a scripting language for the scriptable parts, i.e. Lua or Javascript.

To answer your technical question: You don't want to write your own language and interpreter. That's too much work for you to do. So pick some other language, say Python or Lua, and look for the documentation that lets your C program hand it blocks of code to execute. Of course, the script needs to be able to do something, so you'll need to find how to expose your program's objects to the script. Also, what will happen if a client is running the program when you update its source code in the database? Should the client restart? Are you going to store the entire program as a single row in this database, or did you want to store individual functions? That affects how you structure your updates.
To address other issues with your question: Why do you want to do this? Making "interpreted language" part of your design spec for a system is not often a good sign. Is the real requirement something like this: "I update the program often and I want users to always have the latest copy?" If so, there are other, better ways to go about this (just give us your actual scenario and requirements).

how to transition from C# to python?

i feel like i'm going back to the stone age.
how do i relearn to develop without intellisense (pydev intellisense doesn't count).. in general, how does one successfully leave the comfort of visual studio ?

I recently learned python with a strong C# background.
My advise: Just do it. Sorry, couldn't resist but I'm also serious. Install python and read: Python.org documentation (v2.6). A book might help too -- I like the Python PhraseBook. From there, I started using python to implement solutions for various things. Most notably, ProjectEuler.net questions.
It forced me to consider the languages and built in data structures.
Python is truly easy to use and intuitive. To learn the basics, took me about an hour. To get pretty good with it, took around 5 hours. Of course, there is always more to learn.
Also, I want to note that I would discourage using IronPython or Jython because I feel learning core, regular python is the first step.

Python has rich "introspection" features. In particular, you can find out a lot about built-in features using a command called help() from the Python command line.
Suppose you want to use regular expressions, and want to find out how to use them.
>>> import re
>>> help(re)
You get a nice display of information, automatically shown to you a page at a time (hit the space bar to see the next page).
If you already know you want to use the sub() function from the re module, you can get help on just that:
>>> help(re.sub)
And this help() feature will even work on your own code, as long as you define Python docstrings for your modules, classes, and functions.
You can enable features in the vim editor (or gvim, or vim for Windows) that enable an "IntelliSense"-like autocompletion feature, and you can use Exuberant Ctags to generate hyperlink "tags" to let you navigate quickly through your code. These turn vim into something that is roughly as powerful as an IDE, with the full power of vim for editing. (There isn't an explicit refactoring tool built in to vim, but there are options available.
And as others have noted, you can get IDEs for Python too. I've used the Wingware IDE, and I recommend it. I try to do most of my work with free, open-source software, but that is one piece of proprietary software I would be willing to buy. I have also used Eclipse with the Pydev plugin (I used its refactoring tool and it worked fine).
P.S. Python has a richer feature set than C#, albeit at the cost that your code won't run as fast. Once you get used to Python, you won't feel like you are in the stone age anymore.

One step at a time?
Start off with simple programs (things you can write with your eyes closed in C#), and keep going... You will end up knowing the API by heart.

<rant>
This is sort of the reason that I think being a good visual studio user makes you a bad developer. Instead of learning an API, you look in the object browser until you find something that sounds more or less like what you are looking for, instantiate it, then hit . and start looking for what sounds like the right thing to use. While this is very quick, it also means it takes forever to learn an API in any depth, which often means you end up either re-inventing the wheel (because the wheel is buried under a mountain worth of household appliances and you had no idea it was there), or just doing things in a sub-optimal way. Just because you can find A solution quickly, doesn't mean it is THE BEST solution.
</rant>
In the case of .NET, which ships with about a billion APIs for everything under the sun, this is actually preferred. You need to sift through a lot of noise to find what you are aiming for.
Pythonic code favors one, obvious way to do any given thing. This tends to make the APIs very straight forward and readable. The trick is to learn the language and learn the APIs. It is not terribly hard to do, especially in the case of python, and while not being able to rely on intellisense may be jarring at first, it shouldn't take more then a week or two before you get used to it not being there.
Learn the language and the basic standard libraries with a good book. When it comes to a new library API, I find the REPL and some exploratory coding can get me to a pretty good understanding of what is going on fairly quickly.

You could always start with IronPython and continue to develop in Visual Studio.

The python ide from wingware is pretty nice. Thats what I ended up using going from visual studio C++/.net to doing python.

Don't worry about intellisense. Python is really simple and there really isn't that much to know, so after a few projects you'll be conceiving of python code while driving, eating, etc., without really even trying. Plus, python's built in text editor (IDLE) has a wimpy version of intellisense that has always been more than sufficient for my purposes. If you ever go blank and want to know what methods/properties and object has, just type this in an interactive session:
dir(myobject)

Same way you do anything else that doesn't have IntelliStuff.
I'm betting you wrote that question without the aid of an IntelliEnglish computer program that showed you a list of verbs you could use and automatically added punctuation at the end of your sentences, for example. :-)

I use Eclipse and PyDev, most of the time, and the limited auto-completion help that it provides is pretty useful.
It's not ever going to come up to the level of VS's IntelliSense, and it can't, because of the dynamic nature of Python. But there are compensations, big ones.
The biggest is the breaking of the code-compile-test cycle. It's so easy to write and test prototype code in IDLE that very often it's where I go first: I'll sketch out and test a couple of methods that have to interoperate, figure out that there's something I don't know, learn it, fix my test, and then port the whole thing over to PyDev and watch it work the first time.
Another is that it's a lot simpler. It's really important to know what the standard modules are, and what they do, but for the most part that can be picked up with a little reading. I only use a small handful of modules in my everyday programming - itertools, os, csv (yeah, well), datetime, StringIO - and everything else is there if I need it, but usually I don't.
The stuff that it's really important to know is stuff that IntelliSense couldn't help you with anyway. Auto-completion isn't going to make
self.__dict__.update(kwargs)
make a damn bit of sense; you have to learn what an amazing line of code that is, and why you'd write it, by yourself.
Then you'll think, "how would I even begin to implement something like that in C#?" and realize that the tools these stone-age people are using are a little more sophisticated than you think.

A mistake people coming from C# or Java make a lot is recreate a large class hierarchy like is common in those languages. With Python this is almost never useful. Instead, learn about duck typing. And don't worry too much about the lack of static typing: in practice, it's almost never an issue.

I'm not too familiar with Python so I'll give some general advice. Make sure to print out some reference pages of common functions. Keep them by you(or pinned to a wall or desk) at all times when your programming.. I'm traditionally a "stone age" developer and after developing in VS for a few months I'm finding my hobby programming is difficult without intellisense.. but keep at it to memorize the most common functions and eventually it'll just be natural
You'll also have to get use to a bit more "difficult" of debugging(not sure how that works with python)
While your learning though, you should enjoy the goodness(at least compared to C#) of Python even if you don't have intellisense.. hopefully this will motivate you!

I've only ever used IDLE for python development and it is not fun in the least. I would recommend getting your favorite text editor, mine is notepad++, and praying for a decent plugin for it. I only ever had to go from Eclipse to Visual Studio so my opinions are generally invalid in these contexts.

Pyscripter does a reasonable job at auto-completion/intellisense. I've been using it recently as I started to learn Python/Django, where I've been mainly a C# developer for the last few years.

I suggest going cold turkey - languages like Python shine with great text editors. Choose one you want to become amazing at (vim, emacs, etc.) and never look back.

I use Komodo Edit and it does reasonably good guessing at the autocompletion.

Others have suggested several editors that have intellisense-like capabilities. Try them out.
Also install ipython and use that to learn the language interactively. It is like a souped up version of the regular python interactive shell with lots and lots of added capabilities, and one of the most useful it its extensive context sensitive tab-completion and help.
For example if you type
import r<tab>
it will show all the modules you can import starting with r
import re
re.<tab>
will show all the objects in the re module
re.compile?
will show the docstring and other information about the re.compile function, automatically piping it through a pager if it is longer than a screenful.
re.compile??
will show the source code as well, if available.
Using this I find it is much faster to switch to ipython and query objects directly than it is to look up anything in the docs. You have access to the usual python help() system as well.
ipython has lots and lots of other features - far too many to cover in a short post.

Is there a tool to convert ANSI C code to C#?

I need to import some ANSI C code into a project I'm working on. For reasons I prefer not to go into, I want to refactor the code to C# rather than trying to wrap the original code. It will take me perhaps a couple of days to do the work by hand, but before I start, is there an automated tool that can get me most of the way there? I'm a cheapskate and the work I'm doing is pro bono, so free tools only please.

If manual refactoring is "only" going to take a few days, that would get my vote. Depending on what the C code is doing and how it is written (pointers, custom libraries, etc.) an automated converter may just make a mess. And untangling that mess could be a larger task than just converting by hand.

Setting up, cleaning up, refactoring, and just plain making converted code (if there is even a converter available) would probably be something in the magnitude of weeks or months, so you'll be better served just to go ahead with the manual rewrite.

There is an experimental CLI Back-End and Front-End for GCC. It is already capable of compiling a subset of C programs into CIL, the byte-code that the CLR runs.
(The webpage makes it seem like the code was only developed over a few months and then ignored since then, but it's out of date; ST Microelectronics is continuing maintenance and development.)
You don't specify why you want a C to C# translator, but if you just want to get C and C# to play together without P/Invoke or COM, it might be good enough.

It may make sense to start by getting the existing code to compile as managed C++ aka C++/CLI. Assuming that went smoothly enough, then you have a working, testable foundation on which to build. Move key features to their own classes, and as needed, rewrite as C# along the way.