D语言起步

2007-12-8 我第一次接触D语言,尝试了一下,发现效率还蛮高的.
1.在linux 下安装D语言编译器
  D语言的编译器目前有2个，DMD和GDC，DMD比较容易配置，
  可以从http://www.digitalmars.com/d/dcompiler.html下载最新版
  我下载的是dmd.zip包
  a. 直接解压dmd.zip包在根目录下 /dmd
  b. 设置环境变量
      在/etc/profile 文件后面添加一行
      [root@localhost /]#vi /etc/profile
      export PATH=$PATH:/dmd/bin
  c. 使设置的环境变量生效
      [root@localhost /]#source /etc/profile

2.写个helloWord 测试一下
  a. [root@localhost /]#vi hello.d

    void main()
    {
    
     printf("hello, world!");
    }

  b. [root@localhost /]#dmd hello.d

  c. [root@localhost /]#./hello
3.不用编译直接当作脚本文件来运行


#!/dmd/bin/dmd -run
/* 声明为脚本文件,并且执行它的是dmd*/

/* Hello World in D
   To compile:
     dmd hello.d
   or to optimize:
     dmd -O -inline -release hello.d
*/

import std.stdio;

void main(char[][] args)
{
    writefln("Hello World, Reloaded");

    // auto type inference and built-in foreach
    foreach (argc, argv; args)
    {
        // Object Oriented Programming
        CmdLin cl = new CmdLin(argc, argv);
        // Improved typesafe printf
        writefln(cl.argnum, cl.suffix, " arg: %s", cl.argv);
        // Automatic or explicit memory management
        delete cl;
    }

    // Nested structs and classes
    struct specs
    {
        // all members automatically initialized
        int count, allocated;
    }

    // Nested functions can refer to outer
    // variables like args
    specs argspecs()
    {
        specs* s = new specs;
        // no need for '->'
        s.count = args.length;    // get length of array with .length
        s.allocated = typeof(args).sizeof; // built-in native type properties
        foreach (argv; args)
            s.allocated += argv.length * typeof(argv[0]).sizeof;
        return *s;
    }

    // built-in string and common string operations
    writefln("argc = %d, " ~ "allocated = %d",
argspecs().count, argspecs().allocated);
}

class CmdLin
{
    private int _argc;
    private char[] _argv;

public:
    this(int argc, char[] argv) // constructor
    {
        _argc = argc;
        _argv = argv;
    }

    int argnum()
    {
        return _argc + 1;
    }

    char[] argv()
    {
        return _argv;
    }

    char[] suffix()
    {
        char[] suffix = "th";
        switch (_argc)
        {
          case 0:
            suffix = "st";
            break;
          case 1:
            suffix = "nd";
            break;
          case 2:
            suffix = "rd";
            break;
          default:
    break;
        }
        return suffix;
    }
}
保存为:scripttest.d
[root@localhost /]#chmod +x scripttest.d
[root@localhost /]#./scripttest.d