Re: Ada bench : count words

[tmoran@acm.org]

> - the speed is circa 1/3 of the GCC C version
> ...
> The complete program follows.

  I missed the original post with the URL of the benchmark, but this
appears on my machine to be about 5x as fast (gnatmake -gnato -O2):

with Ada.Calendar,
     Ada.Streams,
     Ada.Streams.Stream_IO,
     Ada.Text_IO,
     Ada.Text_IO.Text_Streams;
procedure Cw is
  use Ada.Streams;
  use type Ada.Calendar.Time;
  Stream  : Ada.Text_IO.Text_Streams.Stream_Access;
  Buffer  : Stream_Element_Array(1 .. 4096);
  Last    : Stream_Element_Offset;
  Lines, Words, Total : Natural := 0;
  In_Word : Boolean := False;
  LF      : constant Stream_Element := Character'pos(Ascii.LF);
  CR      : constant Stream_Element := Character'pos(Ascii.CR);
  EOF_Char: constant Stream_Element := 16#1A#;
  Is_Separator: constant array (Stream_Element) of Boolean
    := (0 .. 32 | 127 .. 159 => True, others => False);
  T0, T1  : Ada.Calendar.Time;
begin

  T0 := Ada.Calendar.Clock;

  Stream := Ada.Text_IO.Text_Streams.Stream(Ada.Text_IO.Current_Input);
  Through_File:
  loop
    Ada.Streams.Read(Ada.Streams.Root_Stream_Type'Class(Stream.all),
                     Buffer, Last);
    for I in 1 .. Last loop
      exit Through_File when Buffer(I) = EOF_Char;
      Total := Total + 1;
      if Is_Separator(Buffer(I)) then
        In_Word := False;
        if Buffer(I) = LF then -- LF counts toward Total and toward Lines
          Lines := Lines + 1;
        elsif Buffer(I) = CR then -- don't count CR as content or as a line
          Total := Total-1;
        end if;
      else
        if not In_Word then
          Words := Words + 1;
          In_Word := True;
        end if;
      end if;
    end loop;
    exit Through_File when Last < Buffer'Last;
  end loop Through_File;

  T1 := Ada.Calendar.Clock;

  Ada.Text_IO.Put_Line(Natural'Image(Lines)
                       & Natural'Image(Words)
                       & Natural'Image(Total));
  Ada.Text_IO.Put_Line("took" & Duration'Image(T1 - T0));
end Cw;