As a gentle introduction to Perl 6, let’s consider a small task that I recently encountered while pursuing one of my hobbies.
Sudoku is a number-placement puzzle played on a grid of 9×9 cells, subdivided into blocks of 3×3 (Figure 3-1). Some of the cells are filled out with numbers from 1 to 9, some are empty. The objective of the game is to fill out the empty cells so that in each row, column, and 3×3 block, each digit from 1 to 9 occurs exactly once.