CIS194/Lecture 02/Scrabble/Scrabble.hs

55 lines
1.7 KiB
Haskell

module Scrabble where
import Words
import Data.List
type Hand = [Char]
formableBy :: String -> Hand -> Bool
formableBy [] _ = True
formableBy (x:xs) hand = let remainingHand = delete x hand in
elem x hand && formableBy xs remainingHand
wordsFromList :: Hand -> [String] -> [String]
wordsFromList hand [] = []
wordsFromList hand (x:[])
| formableBy x hand = [x]
| otherwise = []
wordsFromList hand (x:xs) = wordsFromList hand [x] ++ wordsFromList hand xs
wordsFrom :: Hand -> [String]
wordsFrom hand = wordsFromList hand allWords
type Template = String
wordMatchesTemplate :: String -> Template -> Bool
wordMatchesTemplate [] [] = True
wordMatchesTemplate (w:ws) (t:ts)
| t == '?' = wordMatchesTemplate ws ts
| otherwise = w == t && wordMatchesTemplate ws ts
wordMatchesTemplate _ _ = False
removeTemplateChars :: String -> Template -> String
removeTemplateChars word [] = word
removeTemplateChars word (t:ts)
| t == '?' = removeTemplateChars word ts
| otherwise = removeTemplateChars (delete t word) ts
wordFitsTemplate :: Template -> Hand -> String -> Bool
wordFitsTemplate template hand word = let matchWord = removeTemplateChars word template in
formableBy matchWord hand && wordMatchesTemplate word template
wordsFromListFittingTemplate :: Template -> Hand -> [String] -> [String]
wordsFromListFittingTemplate _ _ [] = []
wordsFromListFittingTemplate template hand (x:xs)
| wordFitsTemplate template hand x = x : wordsFromListFittingTemplate template hand xs
| otherwise = wordsFromListFittingTemplate template hand xs
wordsFittingTemplate :: Template -> Hand -> [String]
wordsFittingTemplate template hand = wordsFromListFittingTemplate template hand allWords