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Diffstat (limited to 'd.html.markdown')
| -rw-r--r-- | d.html.markdown | 67 | 
1 files changed, 39 insertions, 28 deletions
| diff --git a/d.html.markdown b/d.html.markdown index ba24b60f..80c1dc65 100644 --- a/d.html.markdown +++ b/d.html.markdown @@ -23,8 +23,10 @@ about [D](http://dlang.org/). The D programming language is a modern, general-pu  multi-paradigm language with support for everything from low-level features to  expressive high-level abstractions. -D is actively developed by Walter Bright and Andrei Alexandrescu, two super smart, really cool -dudes. With all that out of the way, let's look at some examples! +D is actively developed by a large group of super-smart people and is spearheaded by +[Walter Bright](https://en.wikipedia.org/wiki/Walter_Bright) and +[Andrei Alexandrescu](https://en.wikipedia.org/wiki/Andrei_Alexandrescu). +With all that out of the way, let's look at some examples!  ```c  import std.stdio; @@ -36,9 +38,10 @@ void main() {          writeln(i);      } -    auto n = 1; // use auto for type inferred variables +    // 'auto' can be used for inferring types. +    auto n = 1; -    // Numeric literals can use _ as a digit seperator for clarity +    // Numeric literals can use '_' as a digit separator for clarity.      while(n < 10_000) {          n += n;      } @@ -47,13 +50,15 @@ void main() {          n -= (n / 2);      } while(n > 0); -    // For and while are nice, but in D-land we prefer foreach -    // The .. creates a continuous range, excluding the end +    // For and while are nice, but in D-land we prefer 'foreach' loops. +    // The '..' creates a continuous range, including the first value +    // but excluding the last.      foreach(i; 1..1_000_000) {          if(n % 2 == 0)              writeln(i);      } +    // There's also 'foreach_reverse' when you want to loop backwards.      foreach_reverse(i; 1..int.max) {          if(n % 2 == 1) {              writeln(i); @@ -69,16 +74,18 @@ are passed to functions by value (i.e. copied) and classes are passed by referen  we can use templates to parameterize all of these on both types and values!  ```c -// Here, T is a type parameter. Think <T> from C++/C#/Java +// Here, 'T' is a type parameter. Think '<T>' from C++/C#/Java.  struct LinkedList(T) {      T data = null; -    LinkedList!(T)* next; // The ! is used to instaniate a parameterized type. Again, think <T> + +    // Use '!' to instantiate a parameterized type. Again, think '<T>'. +    LinkedList!(T)* next;  }  class BinTree(T) {      T data = null; -    // If there is only one template parameter, we can omit parens +    // If there is only one template parameter, we can omit the parentheses.      BinTree!T left;      BinTree!T right;  } @@ -93,13 +100,11 @@ enum Day {      Saturday,  } -// Use alias to create abbreviations for types - +// Use alias to create abbreviations for types.  alias IntList = LinkedList!int;  alias NumTree = BinTree!double;  // We can create function templates as well! -  T max(T)(T a, T b) {      if(a < b)          return b; @@ -107,9 +112,8 @@ T max(T)(T a, T b) {      return a;  } -// Use the ref keyword to ensure pass by referece. -// That is, even if a and b are value types, they -// will always be passed by reference to swap +// Use the ref keyword to ensure pass by reference. That is, even if 'a' and 'b' +// are value types, they will always be passed by reference to 'swap()'.  void swap(T)(ref T a, ref T b) {      auto temp = a; @@ -117,13 +121,13 @@ void swap(T)(ref T a, ref T b) {      b = temp;  } -// With templates, we can also parameterize on values, not just types +// With templates, we can also parameterize on values, not just types.  class Matrix(uint m, uint n, T = int) {      T[m] rows;      T[n] columns;  } -auto mat = new Matrix!(3, 3); // We've defaulted type T to int +auto mat = new Matrix!(3, 3); // We've defaulted type 'T' to 'int'.  ``` @@ -133,21 +137,20 @@ have the syntax of POD structures (`structure.x = 7`) with the semantics of  getter and setter methods (`object.setX(7)`)!  ```c -// Consider a class parameterized on a types T, U - +// Consider a class parameterized on types 'T' & 'U'.  class MyClass(T, U) {      T _data;      U _other; -  } -// And "getter" and "setter" methods like so +// And "getter" and "setter" methods like so:  class MyClass(T, U) {      T _data;      U _other; -    // Constructors are always named `this` +    // Constructors are always named 'this'.      this(T t, U u) { +        // This will call the setter methods below.          data = t;          other = u;      } @@ -170,16 +173,24 @@ class MyClass(T, U) {          _other = u;      }  } -// And we use them in this manner +// And we use them in this manner:  void main() { -    auto mc = MyClass!(int, string); +    auto mc = new MyClass!(int, string)(7, "seven"); + +    // Import the 'stdio' module from the standard library for writing to +    // console (imports can be local to a scope). +    import std.stdio; + +    // Call the getters to fetch the values. +    writefln("Earlier: data = %d, str = %s", mc.data, mc.other); -    mc.data = 7; -    mc.other = "seven"; +    // Call the setters to assign new values. +    mc.data = 8; +    mc.other = "eight"; -    writeln(mc.data); -    writeln(mc.other); +    // Call the getters again to fetch the new values. +    writefln("Later: data = %d, str = %s", mc.data, mc.other);  }  ``` | 
