Programming Forums > Application Development > C#

JimmyJim · Jul 22nd, 2006, 11:39 AM

I was looking at C# 3.0(not .net 3.0) today and its quite interesting what they have lined up for the language in the future. Lambda expression, extension methods, type inferencing and LINQ.

Lambda expressions look interesting, but i dont have much knowledge of what they are about and what you would use them for. I think they are based of lambda calculus, which to generalise grately is just another way of expressing a mathamatical function.

Extension methods are ways of extending a class which you dont have the source code for and dont want to make a new class inheriting the one you want to extend. Kind of usefull for adding one or two methods to a class. Maybe this would be confusing, for example in a program someone could add a method to string(or whatever) and then you have to go hunt it down to see what it does.

Type inferencing looks like it could be abused. As you can say:

(Toggle Plain Text)

         var i = 90;
         var s = "Hello World";

This is not dynamically typed like python, but the variable declared takes the type of the expression on the right hand side. I think its to get around the need to type alot, e.g.

(Toggle Plain Text)

       //C# now
       List<string> s = new List<string>();
       //C# 3.0
       var s = new List<string>();

This would mean you dont have to type List<string> twice, but what about this.

(Toggle Plain Text)

      var s = new List<string>();
      s.Add("Hello");
      s.Add("World");
      ...
      var t = s; 
      //now you have to go find out what type s is to know what type t is.

So you can see where it could get anoying and be abused alot.

LINQ is Language Integrated Query. Its a way of accessing data in an object oriented and typed checked way. It looks like a very good idea but to make it work it requires all the other features described to be added.

I know this is quite brief and not very technical. I was wondering what other people thought about these proposed new features and if they are really needed or just add bloat to a very good language. Is this the future in programming getting more declaritive(put simply, you say what you want and the compiler goes and figures out how to do it) and the c# design team are just following the trend(if there is one).

Language design is one of my interests, i find it interesting how different languages work and why some features work well and some dont. If you think im slightly insane then i agree with you lol.

Booooze · Jul 22nd, 2006, 12:10 PM

I see your point, and I don't like it either. Seems sloppy. That's why I left VB6 and came to C#. Now I come to C#, and it gets sloppy? Come on people...
I guess as long as we can still do it the old way, it will be alright. I'll probably look into C# 3.0 later and post back.

Arevos · Jul 22nd, 2006, 1:27 PM

Quote:

Originally Posted by JimmyJim

Lambda expressions look interesting, but i dont have much knowledge of what they are about and what you would use them for.

In terms of C#, they're essentially a quick way of writing anonymous delegates that return a single expression.

In C# 2.0:

 csharp Syntax (Toggle Plain Text) 
Func<int, int> double = delegate(int x) { return x * 2; };
Func<int, int> double = delegate(int x) { return x * 2; };

In C# 3.0:

csharp Syntax (Toggle Plain Text)

Func<int, int> double = x => x * 2;

Quote:

Originally Posted by JimmyJim

Type inferencing looks like it could be abused.

I think you're quite right about this, but I think the benefits outweigh the disadvantages. So long as the people you're programming with are competant (and if they're not, then the var keyword is the least of your worries), then var will be used sparingly.

Quote:

Originally Posted by JimmyJim

I know this is quite brief and not very technical. I was wondering what other people thought about these proposed new features and if they are really needed or just add bloat to a very good language. Is this the future in programming getting more declaritive(put simply, you say what you want and the compiler goes and figures out how to do it) and the c# design team are just following the trend(if there is one).

I recently found myself watching a Python screencast, and in it the author said something which I think is rather relevant to the question you asked: "Code is read more than it is written."

This is a phrase that is so basic as to be almost self evident. You will only write a particular line of code once, whilst that line of code may be read many times, by many different people.

This reminded me of another phrase that has stuck in my mind: "Code is more easily written than it is read." This far from self evident, and I'm not sure I agree with it entirely, but it does make a lot of sense. Reading another person's code is hard. If it wasn't, then we wouldn't have to comment our code. Whether reading is harder than writing is debatable, but understanding what a piece of code does is clearly not a trivial matter.

Given all this, one comes to the conclusion that readability is rather important. A factor that affects readability is how much unnecessary information there is in the code. For example, compare C# 2.0:

 csharp Syntax (Toggle Plain Text) 
MyContainer<Person> people   = new MyContainer<Person>();
MyContainer<Person> children = people.Where(
    delegate (Person person) { return person.age < 18 }
);
MyContainer<Person> people   = new MyContainer<Person>();
MyContainer<Person> children = people.Where(
    delegate (Person person) { return person.age < 18 }
);

To C# 3.0:

 csharp Syntax (Toggle Plain Text) 
var people   = new MyContainer<Person>();
var children = people.Where(person => person.age < 18);
var people   = new MyContainer<Person>();
var children = people.Where(person => person.age < 18);

To my mind, the C# 3.0 code is the more readable, because it reduces the amount of unnecessary information.

On the other side of the coin, sometimes code doesn't give enough necessary information. Compare C# 2.0:

 csharp Syntax (Toggle Plain Text) 
Person person = new Person("Fred", 31, 8);
Person person = new Person("Fred", 31, 8);

To C# 3.0:

 csharp Syntax (Toggle Plain Text) 
var person = new Person {name = "Fred", age = 31, shoeSize = 8};
var person = new Person {name = "Fred", age = 31, shoeSize = 8};

Again, 3.0 wins over 2.0. With 3.0, we can see that the '8' value refers to the person's shoesize, and that '31' refers to his age. In C# 2.0, the answer isn't immediately obvious (especially as Fred's shoe size might be in European measurements).

Quote:

Originally Posted by JimmyJim

Language design is one of my interests, i find it interesting how different languages work and why some features work well and some dont. If you think im slightly insane then i agree with you lol.

One of my interests as well, funnily enough

Dameon · Jul 22nd, 2006, 1:33 PM

The type inferencing can certainly be abused...like other constructs, it will just have to have some style guidlines. Such as only using it when the type is actually in the rhand, rather than another variable.

LINQ should be wildly useful. It should eliminate a lot of loops and conditions for processing data, such as finding an item in a list that meets certain criteria.

The type inferencing with lamdba expressions looks like a nightmare...

JimmyJim · Jul 22nd, 2006, 1:35 PM

Thanks Arevos, i always like to see what other people think and you have explained alot of the stuff i was not completely sure about.

I can see that lambda expressions are quite a nice feature now and im sure i will use them if they ended up in the final specification for c# 3.0. Though im still unsure that type inferencing is worth the hastle that it could create if it is badly used.

I agree that writing code is easier than reading it, but i enjoy looking at how other poeple solve a problem especially if it is different from the way i solved it.

Jul 22nd, 2006, 11:39 AM	#1
JimmyJim Programmer Join Date: Jul 2006 Location: England Posts: 43 Rep Power: 0	Whats C# 3.0 all about? I was looking at C# 3.0(not .net 3.0) today and its quite interesting what they have lined up for the language in the future. Lambda expression, extension methods, type inferencing and LINQ. Lambda expressions look interesting, but i dont have much knowledge of what they are about and what you would use them for. I think they are based of lambda calculus, which to generalise grately is just another way of expressing a mathamatical function. Extension methods are ways of extending a class which you dont have the source code for and dont want to make a new class inheriting the one you want to extend. Kind of usefull for adding one or two methods to a class. Maybe this would be confusing, for example in a program someone could add a method to string(or whatever) and then you have to go hunt it down to see what it does. Type inferencing looks like it could be abused. As you can say: (Toggle Plain Text) var i = 90; var s = "Hello World"; var i = 90; var s = "Hello World"; This is not dynamically typed like python, but the variable declared takes the type of the expression on the right hand side. I think its to get around the need to type alot, e.g. (Toggle Plain Text) //C# now List<string> s = new List<string>(); //C# 3.0 var s = new List<string>(); //C# now List<string> s = new List<string>(); //C# 3.0 var s = new List<string>(); This would mean you dont have to type List<string> twice, but what about this. (Toggle Plain Text) var s = new List<string>(); s.Add("Hello"); s.Add("World"); ... var t = s; //now you have to go find out what type s is to know what type t is. var s = new List<string>(); s.Add("Hello"); s.Add("World"); ... var t = s; //now you have to go find out what type s is to know what type t is. So you can see where it could get anoying and be abused alot. LINQ is Language Integrated Query. Its a way of accessing data in an object oriented and typed checked way. It looks like a very good idea but to make it work it requires all the other features described to be added. I know this is quite brief and not very technical. I was wondering what other people thought about these proposed new features and if they are really needed or just add bloat to a very good language. Is this the future in programming getting more declaritive(put simply, you say what you want and the compiler goes and figures out how to do it) and the c# design team are just following the trend(if there is one). Language design is one of my interests, i find it interesting how different languages work and why some features work well and some dont. If you think im slightly insane then i agree with you lol.

Jul 22nd, 2006, 1:33 PM	#4
Dameon Troll Join Date: Apr 2005 Location: Texas Posts: 732 Rep Power: 4	The type inferencing can certainly be abused...like other constructs, it will just have to have some style guidlines. Such as only using it when the type is actually in the rhand, rather than another variable. LINQ should be wildly useful. It should eliminate a lot of loops and conditions for processing data, such as finding an item in a list that meets certain criteria. The type inferencing with lamdba expressions looks like a nightmare... __________________ MD5(sig) = bcef75433db02e9ad9bf81d6f7c5c270 Last edited by Dameon; Jul 22nd, 2006 at 1:53 PM.

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Jul 22nd, 2006, 12:10 PM	#2
Booooze Expert Programmer Join Date: Mar 2006 Location: Igloo Posts: 710 Rep Power: 3	I see your point, and I don't like it either. Seems sloppy. That's why I left VB6 and came to C#. Now I come to C#, and it gets sloppy? Come on people... I guess as long as we can still do it the old way, it will be alright. I'll probably look into C# 3.0 later and post back.

Jul 22nd, 2006, 1:35 PM	#5
JimmyJim Programmer Join Date: Jul 2006 Location: England Posts: 43 Rep Power: 0	Thanks Arevos, i always like to see what other people think and you have explained alot of the stuff i was not completely sure about. I can see that lambda expressions are quite a nice feature now and im sure i will use them if they ended up in the final specification for c# 3.0. Though im still unsure that type inferencing is worth the hastle that it could create if it is badly used. I agree that writing code is easier than reading it, but i enjoy looking at how other poeple solve a problem especially if it is different from the way i solved it.

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Programming Forums > Application Development > C#

Whats C# 3.0 all about?