cf https://github.com/hyper-blade/scrabble-solvers and https://gist.github.com/occipita/c899478b913b678316ada31085494e87

scrabble.hs

{-# LANGUAGE OverloadedStrings #-}
module Main (main) where

import qualified Data.ByteString.Char8 as B
import System.IO
import Data.List
import qualified Data.Vector as V
import Data.Foldable

generateWords :: [B.ByteString] -> B.ByteString -> [B.ByteString]
generateWords dictionary letters = filter wordMatches dictionary
  where
    wordMatches :: B.ByteString -> Bool
    wordMatches word = B.all (letterCountMatches word) word
    letterCountMatches word letter = letter == '\r' || B.count letter word <= B.count letter letters

scores :: V.Vector Int
scores = V.fromList [1,3,3,2,1,4,2,4,1,8,5,1,3,1,1,3,10,1,1,1,1,4,4,8,4,10]

totalScore :: B.ByteString -> Int
totalScore word = sum (map score (B.unpack word))

score :: Char -> Int
score letter = maybe 0 id (scores V.!? (fromEnum letter - fromEnum 'a'))

sortByScore :: [B.ByteString] -> [B.ByteString]
sortByScore = sortOn totalScore

showResults :: [B.ByteString] -> IO ()
showResults words = traverse_ B.putStrLn $ zipWith showWord [length words, length words - 1 .. 0] words
  where
    showWord num word = B.pack (show num) <> ". " <> word

main :: IO ()
main = do
  putStr "Letters: "
  hFlush stdout
  letters <- B.getLine
  dictionary <- B.readFile "dictionary.txt"
  showResults $ sortByScore $ generateWords (B.lines dictionary) letters