15 Dec
2004
15 Dec
'04
3:45 p.m.
printastable :: [([Int],Word)] -> String
printastable l = concat $ map (\(xs,w) -> (show xs) ++ " " ++ w ++ "\n") l
I'd use
[ c | (xs,w) <- l, c <- (show xs) ++ " " ++ w ++ "\n" ]
instead -- after all, list comprehensions provide a much nicer syntax for map, filter and concat.
I try to stay away from list comprehension because I can't memorize in which order the conditions are processed and I have to introduce new variables. [..]
I find it helpful to compare list comprehensions to nested loops & ifs in imperative languages, so that eg [ E | v1 <- E1, pred2, v3 <- E3 ] 'does the same thing as' for( v1 <- E1 ){ if( pred2 ){ for( v3 <- E3){ put-elem-in-resulting-list( E ) } } } -- Thomas