/* 

  It was just a bug (code golf) in Picat.

  https://codegolf.stackexchange.com/questions/129523/it-was-just-a-bug
  """
  It was just a bug

  Inspired by the bugged output in @Carcigenicate's Clojure answer for the Print this diamond challenge.

  Print this exact text:
  1        2        3        4        5        6        7        8        9        0
  1       2       3       4       5       6       7       8       9       0
  1      2      3      4      5      6      7      8      9      0
  1     2     3     4     5     6     7     8     9     0
  1    2    3    4    5    6    7    8    9    0
  1   2   3   4   5   6   7   8   9   0
  1  2  3  4  5  6  7  8  9  0
  1 2 3 4 5 6 7 8 9 0
  1234567890
  1 2 3 4 5 6 7 8 9 0
  1  2  3  4  5  6  7  8  9  0
  1   2   3   4   5   6   7   8   9   0
  1    2    3    4    5    6    7    8    9    0
  1     2     3     4     5     6     7     8     9     0
  1      2      3      4      5      6      7      8      9      0
  1       2       3       4       5       6       7       8       9       0
  1        2        3        4        5        6        7        8        9        0

  (From the middle outward in both directions, each digit is separated by one more space than the previous line.)

  Challenge rules:
  There will be no input (or an empty unused input).
  Trailing spaces are optional.
  A single trailing new-line is optional.
  Leading spaces or new-lines are not allowed.
  Returning a string-array isn't allowed. You should either output the text, or have a function 
  which returns a single string with correct result.

  General rules:
  This is code-golf, so shortest answer in bytes wins.
  Don't let code-golf languages discourage you from posting answers with non-codegolfing languages. Try to come up with an as short as possible answer for 'any' programming language.
  Standard rules apply for your answer, so you are allowed to use STDIN/STDOUT, functions/method with the proper parameters and return-type, full programs. Your call.
  Default Loopholes are forbidden.
  If possible, please add a link with a test for your code.
  Also, please add an explanation if necessary.
  """

  This program was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

import util.

main => go.

% 101 chars
go=>T=(1..9++[0]).map(to_string),foreach(I in-8..8)T.join(cond(I==0,'',[' ':_ in 1..I.abs])).println end.


% Ungolfed
go_ungolfed ?=>
  T = (1..9++[0]).map(to_string),
  foreach(I in -8..8)
    % Darn, ['':_ in 0..0] give strange result. Fixed with cond/2
    T.join(cond(I==0,'',[' ':_ in 1..I.abs])).println
  end.

% Same idea but using list comprehension instead of a for loop.
% It is actually one line since Picat supports function chaining.
% 99 chars
go2=>[(1..9++[0]).map(to_string).join(cond(I==0,'',[' ':_ in 1..I.abs])):I in-8..8].join("\n").println.

% Not correct. Doesn't print anything since "1234567890".join(...) does not work.
%% go3=>["1234567890".join(cond(I==0,'',[' ':_ in 1..I.abs])):I in-8..8].join("\n").println.