diff --git a/d.html.markdown b/d.html.markdown index d816a312..0ffe3508 100644 --- a/d.html.markdown +++ b/d.html.markdown @@ -109,7 +109,7 @@ void swap(T)(ref T a, ref T b) { auto temp = a; a = b; - b = a; + b = temp; } // With templates, we can also parameterize on values, not just types @@ -118,7 +118,7 @@ class Matrix(uint m, uint n, T = int) { T[n] columns; } -auto mat = new Matrix!(3, 3); +auto mat = new Matrix!(3, 3); // We've defaulted T to int ``` @@ -196,3 +196,47 @@ void main() { With properties, we can add any amount of validation to our getter and setter methods, and keep the clean syntax of accessing members directly! + +Other object-oriented goodness for all your enterprise needs +include `interface`s, `abstract class`es, +and `override`ing methods. + +We've seen D's OOP facilities, but let's switch gears. D offers +functional programming with first-class functions, `pure` +functions, and immutable data. In addition, all of your favorite +functional algorithms (map, filter, reduce and friends) can be +found in the wonderful `std.algorithm` module! + +```d +import std.algorithm; + +void main() { + // We want to print the sum of a list of squares of even ints + // from 1 to 100. Easy! + + // Just pass lambda expressions as template parameters! + auto num = iota(1, 101).filter!(x => x % 2 == 0) + .map!(y => y ^^ 2) + .reduce!((a, b) => a + b); + + writeln(num); +} +``` + +Notice how we got to build a nice Haskellian pipeline to compute num? +That's thanks to a D innovation know as Uniform Function Call Syntax. +With UFCS, we can choose whether to write a function call as a method +or free function all. In general, if we have a function + +```d +f(A, B, C, ...) +``` + +Then we may write + +```d +A.f(B, C, ...) +``` + +and the two are equivalent! No more fiddling to remember if it's +str.length or length(str)!