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> true generics, type inference This has absolutely nothing to do with functional programming. > delegates, lambdas, list comprehensions, anonymous types Syn

> true generics, type inference This has absolutely nothing to do with functional programming. > delegates, lambdas, list comprehensions, anonymous types Syntactic sugar. > higher-order functions, true closures Java has them too. They're called “objects”. > a sprinkle of monads Every higher-order language with strict evaluation (which includes every object-oriented language) already has at least one monad, whose use is pervasive and inescapable. So, unless you have user-definable monads, where is the improvement?

louthy 10y ago
> So, unless you have user-definable monads, where is the improvement? C# does have user-definable monads. There are many in this project (Option, Either, Try, TryOption, Task, Reader, Writer, State, Parser, ...)
- catnaroek 10y ago
  No, you only have user-definable type constructors that happen to be monads if you jump to a metalanguage. (Whatever formal or informal system you use to reason about C# code.) Inside C#, you don't even have the means to assert that they are monads, let alone take advantage of the fact that they are monads.
  - louthy 10y ago
    > you don't even have the means to assert that they are monads, let alone take advantage of the fact that they are monads. Yes, you can. Here's an example from version 2.0 of lang-ext (which is WIP and will be released soon) [1]: [1] https://github.com/louthy/language-ext/blob/type-classes/LanguageExt.Tests/TypeClassMonad.cs https://github.com/louthy/language-ext/blob/type-classes/Lan...
    - catnaroek 10y ago
      That just shows that the result of specializing the monad laws to one specific type constructor, holds. But the monad laws themselves are inexpressible in a general form. If you can't even postulate a theory (the monad signature and its equational laws), it doesn't make sense to talk about what models of the theory exist (concrete instances).

louthy 10y ago

> So, unless you have user-definable monads, where is the improvement? C# does have user-definable monads. There are many in this project (Option, Either, Try, TryOption, Task, Reader, Writer, State, Parser, ...)

catnaroek 10y ago
No, you only have user-definable type constructors that happen to be monads if you jump to a metalanguage. (Whatever formal or informal system you use to reason about C# code.) Inside C#, you don't even have the means to assert that they are monads, let alone take advantage of the fact that they are monads.
- louthy 10y ago
  > you don't even have the means to assert that they are monads, let alone take advantage of the fact that they are monads. Yes, you can. Here's an example from version 2.0 of lang-ext (which is WIP and will be released soon) [1]: [1] https://github.com/louthy/language-ext/blob/type-classes/LanguageExt.Tests/TypeClassMonad.cs https://github.com/louthy/language-ext/blob/type-classes/Lan...
  - catnaroek 10y ago
    That just shows that the result of specializing the monad laws to one specific type constructor, holds. But the monad laws themselves are inexpressible in a general form. If you can't even postulate a theory (the monad signature and its equational laws), it doesn't make sense to talk about what models of the theory exist (concrete instances).