Land of Lisp

A Crazy Formatting Trick for Creating Pretty Tables of Data

Let’s look at one last format example that uses some of the control sequences you’ve already seen, as well as some new ones. This example will illustrate how the varied control sequences can be combined for complex behavior.

> (format t "|˜{˜<|˜%|˜,33:;˜2d ˜>˜}|" (loop for x below 100 collect x))
| 0  1  2  3  4  5  6  7  8  9 |
|10 11 12 13 14 15 16 17 18 19 |
|20 21 22 23 24 25 26 27 28 29 |
|30 31 32 33 34 35 36 37 38 39 |
|40 41 42 43 44 45 46 47 48 49 |
|50 51 52 53 54 55 56 57 58 59 |
|60 61 62 63 64 65 66 67 68 69 |
|70 71 72 73 74 75 76 77 78 79 |
|80 81 82 83 84 85 86 87 88 89 |
|90 91 92 93 94 95 96 97 98 99 |

To create this nicely formatted table of numbers, we first use the looping control ...