[Haskell-cafe] Parse text difficulty

[Ben Rudiak-Gould]

Henning Thielemann wrote:

 >I try to stay away from list comprehension because I can't memorize in
 >which order the conditions are processed [...]

I remember it as being slowest-changing-to-the-left, just like the 
positional notation for integers. E.g.

    [[x,y] | x <- ['1'..'4'], y <- ['0'..'9']]

will give you the numbers from 10 to 49 in order (as strings).

Another way to remember is that it's the same order as its equivalent 
using the list monad:

    do { x <- ['1'..'4']; y <- ['0'..'9']; return [x,y] }

-- Ben