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You can call it a library, but for LINQ to work at least four major features had to be added to the language or runtime: -anonymous types -implicitly typed var

You can call it a library, but for LINQ to work at least four major features had to be added to the language or runtime: -anonymous types -implicitly typed variables -object initializers -lambda expressions It's interesting that all of these features are very widely used (except maybe for anonymous types) outside of LINQ, but LINQ was the driving force for adding them to the language. Anonymous types were needed to do the equivalent of "select field1, field2" that are familiar to SQL programmers, or to have intermediate values in a chain of Select/Where/Select operators. Implicitly typed variables (var) were needed to refer to the above types. Object initializers are needed so you could create the anonymous types, and non-anynymous ones too without breaking the LINQ chain. Lambda expressions of course were needed. All of the above are used outside of LINQ. This was done in 2007. Java got streams and lambda expressions in 2014. JavaScript got it in 2015. The SQL like syntax - well it exists. I think many people don't realize it's there. Everyone uses the method/lambda syntax.

wvenable 8y ago
It's not lambda expressions necessary for LINQ but the ability to access the expression tree and translate C# code into other languages (like SQL). There are not many languages with that feature.
eropple 8y ago
All true! But, as you note, they're prerequisites for LINQ, not LINQ. Thing is, though? These days, I would say that all four of the features you describe are barely table stakes. Having lambdas made C# cool in 2007, but it's not 2007 anymore and that the four features you listed are probably the important new features I can think of since 2007 is why I like C# a lot less today. As is probably obvious from my reference to them, I believe that record types would be a contender for "most important new feature"--even moreso than async/await--after spending a lot of time with Kotlin and data classes, it is nearly impossible to go back. C# provides you with the choice of manually-updated boilerplate or mutable objects through your whole stack. That's what has generally kept me away from C# since exposure to first Scala, later Kotlin, and most recently TypeScript. And, while I now work at a C#-first company (not on the C# backend), I don't see a real reason to change that for me personally until they make writing correct code easier. In many ways, TypeScript seems to me to be a wiser future than what C# is presenting, but that's a whole other kettle of fish.
- balfirevic 8y ago
  > Having lambdas made C# cool in 2007, but it's not 2007 anymore and that the four features you listed are probably the important new features I can think of since 2007 is why I like C# a lot less today. It's not lambdas but expression trees that are the key feature that made LINQ possible. That is pretty unique feature among programming languages. So you might want to reevaluate your opinion about "table stakes features".
  - eropple 8y ago
    Seeing as how every use of expression trees I've ever seen in C# is something like "try in vain to make it so people don't have to understand SQL", perhaps you will forgive me for not being particularly impressed by it. I view C#'s expression tree stuff as a neat experiment. It's cool. But it doesn't and shouldn't change one's programming life.
    - manigandham 8y ago
      Perhaps that's just what you've seen then and not really representative? For example the Roslyn compiler service written in C# uses expression trees to do what it does, and it opens up an entire field of possibilities for meta programming in C#. > But it doesn't and shouldn't change one's programming life. What's an example of something that would?
    - balfirevic 8y ago
      Nice moving the goalpost there (table stakes -> changing one's programming life).
      - eropple 8y ago
        I uh. I don't think any goalposts have moved? When introduced, stuff like lambdas and the libraries that could build on them did do exactly that. But they're table stakes today, in 2018. Where's the movement?
felixfbecker 8y ago
I agree with everything you said, except "JavaScript got it in 2015". JavaScript had first-class functions since its inception in 1995 before any of Java or C#, and methods like `array.map()`/`filter()` etc since ES5.1 in 2011, which were already widely used long before the `=>` syntactic sugar was added in 2015.
- recursive 8y ago
  But those functions only worked on arrays or maybe "array-likes" if you're lucky. Notably, they do not work on lazy enumerables, like LINQ does. And then linq goes farther, and allows them to used on queryable data sources that aren't even enumerable.
  - felixfbecker 8y ago
    JavaScripts stdlib is smaller, C# has a huge stdlib. map/filter on Iterables is just an npm install away, e.g. https://www.npmjs.com/package/iterare https://www.npmjs.com/package/iterare

wvenable 8y ago

It's not lambda expressions necessary for LINQ but the ability to access the expression tree and translate C# code into other languages (like SQL). There are not many languages with that feature.

eropple 8y ago

All true! But, as you note, they're prerequisites for LINQ, not LINQ. Thing is, though? These days, I would say that all four of the features you describe are barely table stakes. Having lambdas made C# cool in 2007, but it's not 2007 anymore and that the four features you listed are probably the important new features I can think of since 2007 is why I like C# a lot less today. As is probably obvious from my reference to them, I believe that record types would be a contender for "most important new feature"--even moreso than async/await--after spending a lot of time with Kotlin and data classes, it is nearly impossible to go back. C# provides you with the choice of manually-updated boilerplate or mutable objects through your whole stack. That's what has generally kept me away from C# since exposure to first Scala, later Kotlin, and most recently TypeScript. And, while I now work at a C#-first company (not on the C# backend), I don't see a real reason to change that for me personally until they make writing correct code easier. In many ways, TypeScript seems to me to be a wiser future than what C# is presenting, but that's a whole other kettle of fish.

balfirevic 8y ago
> Having lambdas made C# cool in 2007, but it's not 2007 anymore and that the four features you listed are probably the important new features I can think of since 2007 is why I like C# a lot less today. It's not lambdas but expression trees that are the key feature that made LINQ possible. That is pretty unique feature among programming languages. So you might want to reevaluate your opinion about "table stakes features".
- eropple 8y ago
  Seeing as how every use of expression trees I've ever seen in C# is something like "try in vain to make it so people don't have to understand SQL", perhaps you will forgive me for not being particularly impressed by it. I view C#'s expression tree stuff as a neat experiment. It's cool. But it doesn't and shouldn't change one's programming life.
  - manigandham 8y ago
    Perhaps that's just what you've seen then and not really representative? For example the Roslyn compiler service written in C# uses expression trees to do what it does, and it opens up an entire field of possibilities for meta programming in C#. > But it doesn't and shouldn't change one's programming life. What's an example of something that would?
  - balfirevic 8y ago
    Nice moving the goalpost there (table stakes -> changing one's programming life).
    - eropple 8y ago
      I uh. I don't think any goalposts have moved? When introduced, stuff like lambdas and the libraries that could build on them did do exactly that. But they're table stakes today, in 2018. Where's the movement?

felixfbecker 8y ago

I agree with everything you said, except "JavaScript got it in 2015". JavaScript had first-class functions since its inception in 1995 before any of Java or C#, and methods like `array.map()`/`filter()` etc since ES5.1 in 2011, which were already widely used long before the `=>` syntactic sugar was added in 2015.

recursive 8y ago
But those functions only worked on arrays or maybe "array-likes" if you're lucky. Notably, they do not work on lazy enumerables, like LINQ does. And then linq goes farther, and allows them to used on queryable data sources that aren't even enumerable.
- felixfbecker 8y ago
  JavaScripts stdlib is smaller, C# has a huge stdlib. map/filter on Iterables is just an npm install away, e.g. https://www.npmjs.com/package/iterare https://www.npmjs.com/package/iterare