Skip to main content

Home/ Haskell/ Group items tagged fix

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
anonymous

Fix Slow Running Computer Now - 0 views

My computer is running so slow so I contact Fix Slow Computers Online. They offer online computer support services to fix slow computers. They have the best computer tech specialists who know how t...

fix slow computers

started by anonymous on 12 May 11 no follow-up yet
anonymous

Getting Used to Help and Support - 0 views

I have never been used to getting help and support with all my problems. But when it comes to computer problems, I am glad Computer Tech Help And Support is helping me out. Whenever my PC is in tr...

help and support

started by anonymous on 12 May 11 no follow-up yet
Javier Neira

Learn You a Haskell for Great Good! - Types and Typeclasses - 0 views

learnyouahaskell.com/types-and-typeclasses

type classes haskell tutorial intro

shared by Javier Neira on 22 Dec 09 - Cached
  • That's why we can use explicit type annotations. Type annotations are a way of explicitly saying what the type of an expression should be. We do that by adding :: at the end of the expression and then specifying a type.
Javier Neira

Understanding Haskell Monads - 0 views

ertes.de/monads.html

haskell monads tutorial learning

shared by Javier Neira on 16 Dec 09 - Cached
  • The opposite of referentially transparent is referentially opaque. A referentially opaque function is a function that may mean different things and return different results each time, even if all arguments are the same.
  • a function that just prints a fixed text to the screen and always returns 0, is referentially opaque, because you cannot replace the function call with 0 without changing the meaning of the program.
  • n fact, a function, which doesn't take any arguments, isn't even a function in Haskell. It's simply a value. A number of simple solutions to this problem exist. One is to expect a state value as an argument and produce a new state value together with a pseudorandom number: random :: RandomState -> (Int, RandomState)
  • ...12 more annotations...
  • A general purpose language is almost useless, if you can't develop user interfaces or read files. We would like to read keyboard input or print things to the terminal.
  • We have seen that we can solve this problem by expecting a state argument. But what's our state? The state of the terminal?
  • We seem to have found a useful solution to our problem. Just pass the state value around. But there is a problem with this approach.
  • A very special feature of Haskell is the concept of generalization. That means, instead of implementing an idea directly, you rather try to find a more general idea, which implies your idea as a special case.
  • However, the traditional programmer never had to face generalization. At most they faced abstraction,
  • they are a very abstract structure, which allows implementing functionality at an incredibly general level.
  • Haskell [1] is a purely functional programming language. Functions written in it are referentially transparent. Intuitively that means that a function called with the same arguments always gives the same result.
  • askell takes another approach. Instead of passing the world state explicitly, it employs a structure from category theory called a monad.
  • They are an abstract structure, and at first it can be difficult to understand where they are useful. The two main interpretations of monads are as containers and as computations.
  • The ⊥ value is a theoretical construct. It's the result of a function, which never returns, so you can't observe that value directly. Examples are functions, which recurse forever or which throw an exception. In both cases, there is no ordinary returning of a value.
  • Now that Nothing is a valid result, our function handles all cases.
  • You have some computation with a certain type of result and a certain structure in its result (like allowing no result, or allowing arbitrarily many results), and you want to pass that computation's result to another computation.
shalani mujer

Trusted PC Tech Support - 1 views

Computers are the most essential commodity for me, especially for my business. That is why whenever I experiences computer trouble, I would really look for a PC tech support specialist to fix my co...

PC tech support

started by shalani mujer on 30 Sep 11 no follow-up yet
1 - 5 of 5
Showing 20▼ items per page