CS314 HW 4
Hangman
Write an implementation of the game “hangman” in Haskell, where the user
must guess a word. Use the provided words.txt file.
• Pick a random word from the words.txt file
• Display underscores for each unguessed letter
• Read a character from the user and replace the underscores with that
letter where it matches the actual word (if any)
• Continue reading guesses from the user
• When the user gets all the letters correct, exit
To keep things simpler, you don’t have to keep track of the number of guesses
or letters already guessed, so the user will always win eventually. You can
assume the input format will be correct.
For example, here the word randomly picked was “strongest”. The first,
third, etc. lines are the current state of the word being guessed. The second,
fourth, etc. lines are the user inputting a letter to try:
_________
e
______e__
s
s_____es_
h
s_____es_
t
st____est
r
str___est
a
str___est
o
stro__est
n
stron_est
g
strongest
Some possibly useful functions:
• getLine :: IO String
• lines :: String - [String]
• randomRIO :: Random a = (a, a) - IO a
(in System.Random)
• readFile :: FilePath - IO String
(FilePath is another name for String)
• words :: String - [String]
Note that in recent versions of ghc, import System.Random will give an
error, since random is no longer included by default. It should work on ilab,
though, since that uses an older ghc.
If you want to develop using a more recent version, you can look into how to
set up a project using Stack (https://docs.haskellstack.org/en/stable/README/)
and then add “- random = 1.1” under dependencies in package.yaml. Note
that your submission will be run on ilab without stack, though.
Submission
Please submit a single file named hw4.hs on Sakai.
You should have a main function, so that your hangman game can be executed using runhaskell hw4.hs.
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