Ars Technica Tours Mono

Kevin Francis writes "Over the coming weeks, Ars Technica will be taking a look at Mono, including a basic introduction to Mono, MonoDevelop, and C#, and then branching out to GTK#, database access, ASP.NET, advanced C# topics, and conclude with a discussion of the future of Mono, and the C# standard. All the examples will work on Windows and Linux, with OSX support coming shortly. Part 1 of the series is online now."

Comments

Re:Will the coders use it though?

[Random Web Developer]

I am writing an app for mono that is supposed to run on linux mac and windows in the end. From what I see it's nowhere near just starting a .NET app on linux using mono.

The app clearly has to be written with crossplatform execution in mind. (I know this goes for c and java too, but some people seem to think they will run office on mono in the future.).
You need to steer clear of anything that depends on a platform.
- if you define a path, make sure you use path.combine or path.directoryseparatorchar instead of a / of \.
- don't depend on environment variables
- pay attention to casing, don't say "file.ext" when it's "File.ext"

I know it should be ovbious to any cross platform dev out there, but I just thought I'd bust some bubbles with some of the less informed.

Re:Libraries

[ajp]

Uninformed slashdotters with tin foil hats should click this link.
ECMA-335 Common Language Infrastructure (of which .NET, Rotor and Mono are implementations.)

Re:Bull

[cbiffle]

And, of course, there's the fact that his latter two complaints are kind of sort of fixed in 1.5.

So... :-)

Personally, I think the C# folks make too much of a big deal about the mandatory exception handling in Java. Heard a fellow from Microsoft say "Frequently, Java folks just put an empty catch() block to catch the exception they know won't happen, so why make it mandatory?"

I've got bad news for you. I find situations like that about once a week when auditing my programmers' code, and it's almost always a situation that -can- happen, but the programmer couldn't see it.

Don't trust the programmer. I know, I am one. :-)

Re:Will the coders use it though?

[moonbender]

How is this different from Java? In my opinion Java makes things harder than it needs to be. For starters, enforced exception handling can't auto-box/unbox primitive types and doesn't support arbitrary length parameter lists String.Format() style.

Right. Of course that's all about to change - from the Java 1.5 ("5") new features site:

Autoboxing/Unboxing
This facility eliminates the drudgery of manual conversion between primitive types (such as int) and wrapper types (such as Integer). Refer to JSR 201.

Varargs
This facility eliminates the need for manually boxing up argument lists into an array when invoking methods that accept variable-length argument lists. Refer to JSR 201.

You still need to deal with exceptions - that's a bad thing?

Re:Will the coders use it though?

[dekeji]

Strangely that assumption is quite widespread. I think I've tracked down the source [mono-project.com] though.

Yes, you have correctly tracked down the source of that misconception. It's an easy misconception to have, given what the Mono project writes about itself.

Now, dig down a little deeper and go to the downloads. What do you see? A "Mono Stack" on the left, consisting of OSS libraries and APIs, and a .NET stack on the right, consisting of .NET libraries and APIs. You can pick one or the other, or both. Neat, huh? Now, also note the relative sizes of the Mono and .NET stacks.

Now, turn to the FAQ:

Question 132: Is Mono only an implementation of the .NET Framework?

Mono implements both the .NET Framework, as well as plenty of class libraries that are either UNIX specific, Gnome specific, or that are not part of the .NET Framework but people find useful.

Question 50: Can mono run the WebMatrix?

No. That requires System.Windows.Forms support which is not currently implemented.

Question 40: Do you fear that Microsoft will change the spec and render Mono useless?

No. Microsoft proved with the CLI and the C# language that it was possible to create a powerful foundation for many languages to inter-operate. We will always have that.

Even if changes happened in the platform which were undocumented, the existing platform would a value on its own.

What does that tell you?

• A lot of Mono software (most, in fact) already is completely incompatible with Microsoft .NET, since Mono doesn't even implement important parts of .NET, but does provide extensive non-.NET libraries that are being used by Mono applications. So, .NET compatibilty just doesn't matter to most Mono developers.
  
• People know that Microsoft could change .NET, and it generally doesn't matter to them.
  

Why is the Mono project seemingly saying one thing and delivering another? Well, in part, it's because the term ".NET" is really ambiguous. In part, it's because where their money comes from and where their commercial interests are (they aren't doing this out of religion, they are in it for commercial purposes).

So, your confusion is understandable. I wish the Mono project were clearer on their front page, too, but I suspect they have reasons for what they are doing. Either way, you should really dig a little deeper.