initializing a board from a string, at compile-time

gistfile1.d

enum COLOR : byte { BLANK, BLACK, WHITE };
enum TYPE  : byte { NA, MAN, KING };

struct Piece { 
  COLOR color; TYPE type; 
  string toString() {
    if (color == COLOR.BLANK) 
      return ".";
    if (color == COLOR.WHITE)
      return (type == TYPE.MAN) ? "w" : "W";
    else
      return (type == TYPE.MAN) ? "b" : "B";
  }
}

enum W = 8, H = 8;
alias Board = Piece[H][W];


Board initialize(dstring data) {
  Board board;
  foreach(r; 0..H)
    foreach(c; 0..W) {
      auto mark = data[r*W+c];
      if (mark == '.')
	continue;
      if (mark == 'b' || mark == 'B')
	board[r][c].color = COLOR.BLACK;
      if (mark == 'w' || mark == 'W')
	board[r][c].color = COLOR.WHITE;
      board[r][c].type = 
	(mark == 'W' || mark == 'B') ? TYPE.KING : TYPE.MAN;
    }
  return board;
}

void main() {
  import std.stdio;

  enum dstring data = 
    "ww..W..W"
    "........"
    "........"
    "........"
    "........"
    "........"
    "........"
    "..b.BB.b";
  
  // we can evaluate at compile time!
  enum Board board = initialize(data);
  
  foreach(row; board) {
    foreach(piece; row)
      write(piece);
    writeln();
  }
}