Align columns: Difference between revisions

Or, using the Text module rather than Strings:

<lang haskell>import Data.List as L

import Data.Text as T

import Data.Ord (comparing)

cols :: [[Text]]

cols =

L.transpose $

(splitOn (pack "$") . pack) <$>

[ "Given$a$text$file$of$many$lines,$where$fields$within$a$line$"

, "are$delineated$by$a$single$'dollar'$character,$write$a$program"

, "that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$"

, "column$are$separated$by$at$least$one$space."

, "Further,$allow$for$each$word$in$a$column$to$be$either$left$"

, "justified,$right$justified,$or$center$justified$within$its$column."

]

main :: IO ()

main =

mapM_ putStrLn $

[ (\cols f ->

(unpack . T.unlines) $

T.unwords <$> L.transpose ((\(xs, n) -> f (n + 1) ' ' <$> xs) <$> cols))

(L.zip cols ((T.length . maximumBy (comparing T.length)) <$> cols))

] <*>

[justifyLeft, justifyRight, center]</lang>

{{Out}}

<pre>

Given a text file of many lines, where fields within a line

are delineated by a single 'dollar' character, write a program in each

that aligns each column of fields by ensuring that words either left

column are separated by at least one space. to be

Further, allow for each word in a column column.

justified, right justified, or center justified within its

Given a text file of many lines, where fields within a line

are delineated by a single 'dollar' character, write a program in each

that aligns each column of fields by ensuring that words either left

column are separated by at least one space. to be

Further, allow for each word in a column column.

justified, right justified, or center justified within its

Given a text file of many lines, where fields within a line

are delineated by a single 'dollar' character, write a program in each

that aligns each column of fields by ensuring that words either left

column are separated by at least one space. to be

Further, allow for each word in a column column.

justified, right justified, or center justified within its </pre>