Copyright	© Frank Jung 2017-2026
License	BSD-3-Clause
Maintainer	frankhjung@linux.com
Stability	stable
Portability	portable
Safe Haskell	Safe-Inferred
Language	Haskell2010

WordPuzzle

Description

Supporting functions for solving letter word puzzles.

Notes

Is functions return a boolean:

isXyz :: a -> Bool

Validate functions return a Validation:

validateXyz :: a -> Validation [ValidationError] a

Synopsis

data WordPuzzle = WordPuzzle {
- size :: Int
- mandatory :: Char
- letters :: String
- dictionary :: FilePath
- repeats :: Bool
}
validateSize :: Int -> Validation [ValidationError] Int
validateLetters :: String -> Validation [ValidationError] String
nineLetters :: String -> ByteString -> Bool
spellingBee :: String -> ByteString -> Bool
solve :: WordPuzzle -> IO ()
solver :: WordPuzzle -> InputStream ByteString -> IO (InputStream ByteString)
data ValidationError
- = InvalidSize (Int, Int) Int
- | InvalidLetters String
- | UnexpectedValue String
validate :: Bool -> Int -> String -> FilePath -> Validation [ValidationError] WordPuzzle
toEither :: Validation e a -> Either e a

Documentation

data WordPuzzle Source #

Represent parameters required for the puzzle.

Constructors

WordPuzzle
Fields size :: Int minimum size of words (must be between 4 and 9) mandatory :: Char mandatory character in word letters :: String letters to make words (4–9 unique lowercase characters) dictionary :: FilePath dictionary for valid words repeats :: Bool whether letters can be repeated

Instances

Instances details

Show WordPuzzle Source #
Instance details Defined in WordPuzzle Methods showsPrec :: Int -> WordPuzzle -> ShowS # show :: WordPuzzle -> String # showList :: [WordPuzzle] -> ShowS #

validateSize :: Int -> Validation [ValidationError] Int Source #

Validate size of word.

validateLetters :: String -> Validation [ValidationError] String Source #

Validate letters.

nineLetters Source #

Arguments

:: String	valid letters
-> ByteString	dictionary word to check
-> Bool	true if dictionary word matches letters

Check if a word contains only characters from a letters list.

Uses a strict left fold over the input word with accumulator (mask, ok):

mask is a bitset of already seen letters.
ok tracks whether all checks have passed so far.

For each character, the fold:

fails if the character is not in the valid letter pool,
fails if the character bit is already set (repeated letter),
otherwise sets the bit and continues.

Assumes that the letter pool is valid (see isLetters).

spellingBee Source #

Arguments

:: String	valid letters
-> ByteString	dictionary word to check
-> Bool	true if dictionary word matches letters

Check if a word contains only characters from a letters list. Repeating characters are allowed.

Assumes that the letter pool is valid (see isLetters).

solve :: WordPuzzle -> IO () Source #

Solve word puzzle given a dictionary of words.

Where each word:

must be greater than the minimum word length
must contain mandatory character
must contain only valid characters
if repeats are not allowed, must not exceed valid character frequency
when repeats are enabled there is no upper limit on word length; the word may be longer than the letter pool itself.

Example:

solve (WordPuzzle 4 a "abcdefghij" "dictionary.txt")

Method:

open file
split into lines
filter
print each
force traversal to EOF

solver :: WordPuzzle -> InputStream ByteString -> IO (InputStream ByteString) Source #

Filter words from an input stream based on the puzzle constraints.

data ValidationError Source #

Error given on invalid parameter.

Constructors

InvalidSize (Int, Int) Int	expected range and actual size
InvalidLetters String	actual letters (should be 4-9 unique lowercase letters)
UnexpectedValue String	couldn't parse value

Instances

Instances details

Show ValidationError Source #	Show `ValidationError` as string.
Instance details Defined in WordPuzzle Methods showsPrec :: Int -> ValidationError -> ShowS # show :: ValidationError -> String # showList :: [ValidationError] -> ShowS #
Eq ValidationError Source #
Instance details Defined in WordPuzzle Methods (==) :: ValidationError -> ValidationError -> Bool # (/=) :: ValidationError -> ValidationError -> Bool #

validate :: Bool -> Int -> String -> FilePath -> Validation [ValidationError] WordPuzzle Source #

Validate program parameters.

toEither :: Validation e a -> Either e a #

Converts from Validation to Either.