RosettaCodeData/Task/Range-expansion/Ada/range-expansion.ada
Ingy döt Net b83f433714 tasks a-s
2013-04-10 23:57:08 -07:00

66 lines
1.9 KiB
Ada

with Ada.Text_IO; use Ada.Text_IO;
procedure Test_Range_Expansion is
type Sequence is array (Positive range <>) of Integer;
function Expand (Text : String) return Sequence is
To : Integer := Text'First;
Count : Natural := 0;
Low : Integer;
function Get return Integer is
From : Integer := To;
begin
if Text (To) = '-' then
To := To + 1;
end if;
while To <= Text'Last loop
case Text (To) is
when ',' | '-' => exit;
when others => To := To + 1;
end case;
end loop;
return Integer'Value (Text (From..To - 1));
end Get;
begin
while To <= Text'Last loop -- Counting items of the list
Low := Get;
if To > Text'Last or else Text (To) = ',' then
Count := Count + 1;
else
To := To + 1;
Count := Count + Get - Low + 1;
end if;
To := To + 1;
end loop;
return Result : Sequence (1..Count) do
Count := 0;
To := Text'First;
while To <= Text'Last loop -- Filling the list
Low := Get;
if To > Text'Last or else Text (To) = ',' then
Count := Count + 1;
Result (Count) := Low;
else
To := To + 1;
for Item in Low..Get loop
Count := Count + 1;
Result (Count) := Item;
end loop;
end if;
To := To + 1;
end loop;
end return;
end Expand;
procedure Put (S : Sequence) is
First : Boolean := True;
begin
for I in S'Range loop
if First then
First := False;
else
Put (',');
end if;
Put (Integer'Image (S (I)));
end loop;
end Put;
begin
Put (Expand ("-6,-3--1,3-5,7-11,14,15,17-20"));
end Test_Range_Expansion;