Trees in raw text - how about matrices ?

I think this might be relevant for this community :)

I learned of a nice way to notate trees in raw text. It is as follows:

-a
 |
 +-aa
 | |
 | +-aaa
 | |
 | +-aab
 |
 +-ab
   |
   +-aba
   |
   +-abb

I hope this example demonstrates it fine :)

I was wondering though - Are there any good ways to notate matrices in raw text ?

Please share, if you have any notation for matrices or other nice ways to notate stuff in raw text :)