A lambda is just an anonymous function – a function defined with no name. In some languages, such as Scheme, they are equivalent to named functions. In fact, the function definition is re-written as binding a lambda to a variable internally. In other languages, like Python, there are some (rather needless) distinctions between them, but … Read more
If you want to get a feel for FRP, you could start with the old Fran tutorial from 1998, which has animated illustrations. For papers, start with Functional Reactive Animation and then follow up on links on the publications link on my home page and the FRP link on the Haskell wiki. Personally, I like … Read more
What functionality does functools.partial offer that you can’t get through lambdas? Not much in terms of extra functionality (but, see later) – and, readability is in the eye of the beholder. Most people who are familiar with functional programming languages (those in the Lisp/Scheme families in particular) appear to like lambda just fine – I … Read more
An example in JavaScript Here’s an example using JavaScript. Currently, most browsers do not support tail call optimisation and therefore the following snippet will fail const repeat = n => f => x => n === 0 ? x : repeat (n – 1) (f) (f(x)) console.log(repeat(1e3) (x => x + 1) (0)) // 1000 … Read more
I’m going to order this guide by the level of skill you have in Haskell, going from an absolute beginner right up to an expert. Note that this process will take many months (years?), so it is rather long. Absolute Beginner Firstly, Haskell is capable of anything, with enough skill. It is very fast (behind … Read more
First: The term monad is a bit vacuous if you are not a mathematician. An alternative term is computation builder which is a bit more descriptive of what they are actually useful for. They are a pattern for chaining operations. It looks a bit like method chaining in object-oriented languages, but the mechanism is slightly … Read more
You can use slicing to return the reversed list: l[::-1]
I think the accepted answer is great, but it seems many people have failed to grasp some fundamental points. First, Scala’s for comprehensions are equivalent to Haskell’s do notation, and it is nothing more than a syntactic sugar for composition of multiple monadic operations. As this statement will most likely not help anyone who needs … Read more
Variable scope When you declare a local variable, that variable has a scope. Generally, local variables exist only within the block or function in which you declare them. function() { var a = 1; console.log(a); // works } console.log(a); // fails If I try to access a local variable, most languages will look for it … Read more
Does JavaScript have a method like “range()” to generate a range within the supplied bounds?