用Ada语言写了个输出自己的程序

[vimacs]

之前见过好几种语言的quine，但是自己没写过，今天试着用Ada写一个，模仿wikipedia上Java的版本。
我觉得主要难点有两个，一个是引号的处理，我可以使用 Character'Val(34) 代替引号；另一个是Ada数组最后一个元素后面不能加逗号，于是我在数组最后加一个null元素。写了一上午终于拼了一个出来。

代码:

with Ada.Text_IO; use Ada.Text_IO;

procedure Ada_Quine is
    type String_Access is access String;
    Prefix : constant String := (1 .. 8 => ' ') & ('n', 'e', 'w', ' ', 'S', 't', 'r', 'i', 'n', 'g', ''', '(', Character'Val(34));
    Suffix : constant String := (Character'Val(34), ')', ',');
    NullStr: constant String := (1 .. 8 => ' ') & ('n', 'u', 'l', 'l');
    Myself: constant array (1 .. 27) of String_Access := (
        new String'("with Ada.Text_IO; use Ada.Text_IO;"),
        new String'(""),
        new String'("procedure Ada_Quine is"),
        new String'("    type String_Access is access String;"),
        new String'("    Prefix : constant String := (1 .. 8 => ' ') & ('n', 'e', 'w', ' ', 'S', 't', 'r', 'i', 'n', 'g', ''', '(', Character'Val(34));"),
        new String'("    Suffix : constant String := (Character'Val(34), ')', ',');"),
        new String'("    NullStr: constant String := (1 .. 8 => ' ') & ('n', 'u', 'l', 'l');"),
        new String'("    Myself: constant array (1 .. 27) of String_Access := ("),
        new String'("    );"),
        new String'("begin"),
        new String'("    for I in 1 .. 8 loop"),
        new String'("        Put_Line(Myself(I).all);"),
        new String'("    end loop;"),
        new String'(""),
        new String'("    for S of Myself loop"),
        new String'("        if S /= null then"),
        new String'("            Put_Line(Prefix & S.all & Suffix);"),
        new String'("        else"),
        new String'("            Put_Line(NullStr);"),
        new String'("        end if;"),
        new String'("    end loop;"),
        new String'(""),
        new String'("    for I in 9 .. Myself'Last - 1 loop"),
        new String'("        Put_Line(Myself(I).all);"),
        new String'("    end loop;"),
        new String'("end Ada_Quine;"),
        null
    );
begin
    for I in 1 .. 8 loop
        Put_Line(Myself(I).all);
    end loop;

    for S of Myself loop
        if S /= null then
            Put_Line(Prefix & S.all & Suffix);
        else
            Put_Line(NullStr);
        end if;
    end loop;

    for I in 9 .. Myself'Last - 1 loop
        Put_Line(Myself(I).all);
    end loop;
end Ada_Quine;