Align columns: Difference between revisions

Or, using '''Text''' and its functions as an alternative to '''[Char]''' strings:

<lang haskell>import Data.List (transpose, zip, maximumBy)

import Data.Text as T

(Text, pack, unpack, splitOn, unlines, unwords, length,

justifyLeft, justifyRight, center, replicate)

import Data.Ord (comparing)

rows :: [[Text]]

rows =

(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."

]

intCols :: Int

intCols = maximum (Prelude.length <$> rows)

cols :: [[Text]]

cols =

transpose $

(\xs -> xs ++ Prelude.replicate (intCols - Prelude.length xs) (pack "")) <$> rows

main :: IO ()

main =

mapM_ putStrLn $

[ (\cols f ->

(unpack . T.unlines) $

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

(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

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.

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.

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. </pre>