Dart v1.23 added a new syntax for writing function types which also works in-line. void doSomething(Function(int) f) { f(123); } It has the advantage over the function-parameter syntax that you can also use it for variables or anywhere else you want to write a type. void doSomething(Function(int) f) { Function(int) g = f; g(123); } … Read more
Just look at the Wikipedia article to get your definition: Tacit programming (point-free programming) is a programming paradigm in which a function definition does not include information regarding its arguments, using combinators and function composition […] instead of variables. Haskell example: Conventional (you specify the arguments explicitly): sum (x:xs) = x + (sum xs) sum … Read more
Lisp is a large and complex language with a large and complex runtime to support it. For that reason, Lisp is best suited to large and complicated problems. Now, a complex problem isn’t the same as a complicated one. A complex problem is one with a lot of small details, but which isn’t hard. Writing … Read more
Hindley-Milner is a type system discovered independently by Roger Hindley (who was looking at logic) and later by Robin Milner (who was looking at programming languages). The advantages of Hindley-Milner are It supports polymorphic functions; for example, a function that can give you the length of the list independent of the type of the elements, … Read more
you can use moviesTitles.map((title) => Tab(text: title)).toList() example: bottom: new TabBar( controller: _controller, isScrollable: true, tabs: moviesTitles.map((title) => Tab(text: title)).toList() , ),
There is a difference. When you say that a language has first-class functions, it means that the language treats functions as values – that you can assign a function into a variable, pass it around etc. Higher-order functions are functions that work on other functions, meaning that they take one or more functions as an … Read more
Understanding pattern matching requires explaining three parts: Algebraic data types. What pattern matching is Why its awesome. Algebraic data types in a nutshell ML-like functional languages allow you define simple data types called “disjoint unions” or “algebraic data types”. These data structures are simple containers, and can be recursively defined. For example: type ‘a list … Read more
Read Functional Programming in a Nutshell. There are lots of advantages to stateless programming, not least of which is dramatically multithreaded and concurrent code. To put it bluntly, mutable state is enemy of multithreaded code. If values are immutable by default, programmers don’t need to worry about one thread mutating the value of shared state … Read more
Because all those advantages are also disadvantages. Stateless programs; No side effects Real-world programs are all about side effects and mutation. When the user presses a button it’s because they want something to happen. When they type in something, they want that state to replace whatever state used to be there. When Jane Smith in … Read more
Thank God that the software-engineering people have not yet discovered functional programming. Here are some parallels: Many OO “design patterns” are captured as higher-order functions. For example, the Visitor pattern is known in the functional world as a “fold” (or if you are a pointy-headed theorist, a “catamorphism”). In functional languages, data types are mostly … Read more