example.hs

import           Data.List             (sortOn)
import qualified Data.Text             as ST   
import           Text.LaTeX            (LaTeXT, execLaTeXM, render, fromString)
import           Data.Functor.Identity (Identity)
import           Text.Pandoc           (readerParseRaw, writerTemplate, readLaTeX, def, writeLaTeX)
import           Text.Pandoc.PDF       (makePDF)
import           Data.Monoid           ((<>))
import qualified Data.ByteString.Lazy as LBS
import qualified Data.Text.Lazy as LT
import qualified Data.Text.Lazy.Encoding as LT
import           Text.Printf (printf)
import           Formatting (format, commas)

class RowType r where

doFileRun :: (RowType a, Ord i) => (a -> LaTeXT Identity ()) -> (a -> i) -> [ a ] -> String -> FilePath -> i -> IO ()
doFileRun makeRow f allRows template outputFile minAmount = do
  let
    filtered = filter (\v -> (f v) >= minAmount) allRows
    sorted = reverse $ sortOn f filtered
    raw_latex = ((mapM_ makeRow sorted) |> execLaTeXM |> render) :: ST.Text
    result = readLaTeX (def { readerParseRaw = True }) $ ST.unpack raw_latex
    pandoc = either (error "unable to parse") id result
  putStrLn $ outputFile <> " b " <> (show $ length filtered)
  res <- makePDF "pdflatex" writeLaTeX (def { writerTemplate = Just template }) pandoc
  let
    rawPdf = either ( error . LT.unpack . LT.decodeUtf8) id res
  LBS.writeFile outputFile rawPdf
  putStrLn $ "wrote output to: " <> outputFile
  pure ()

text :: (Monad m) => ST.Text -> LaTeXT m ()
text = fromString . ST.unpack

makeRow :: Monad m => Row -> LaTeXT m ()
makeRow r = do
  let
    list :: [ (T.Text, Row -> T.Text) ]
    list = [
          ("Last Name:", lastName)
        , ("First Name:", firstName)
        , ("Middle Name:", middleName)
        , ("Address :", address1)
      ]
    formatPage :: Monad m => [ (T.Text, Row -> T.Text) ] -> LaTeXT m ()
    formatPage fmt = mapM_ (\(a,b) -> do { text a & text (b r) ; lnbk }) fmt
  tabular Nothing [ LeftColumn, LeftColumn ] $ do
    formatPage list
  newpage
  "\n"



elsewhere:
  doFileRun makeRow fieldAccessor (_rows file) template "output.pdf" 10000