[Haskell-beginners] Error Message when trying to solve alphametic(SEND + MORE = MONEY)
Sok Ha Chang
shaegis at gmail.com
Sun Jan 26 13:29:24 UTC 2014
Thank you to kind help.
From now on, I will follow your way.
Have a nice day.
Thanks, again.
Sincerely, S. Chang
2014. 1. 26. 오후 9:31 Matthew Moppett <matthewmoppett at gmail.com> 작성:
> Sorry about the last post -- I accidentally clicked "send" before I'd written my message.
>
> Sok Ha:
>
> expr = show send ++ "+" ++ show more ++ "=" show money
>
> should read
>
> expr = show send ++ "+" ++ show more ++ "=" ++ show money
>
> The error message is rather cryptic -- ghc seems to assume that "=" must be intended as a function, since it it has other values (potential arguments) to the right of it. I usually don't spend much time trying to figure out ghc error messages unless I really can't solve the problem by just looking over the offending line carefully. Very often it's just a typo (as it seems to be in your case).
>
>
>> On Sun, Jan 26, 2014 at 7:24 PM, Matthew Moppett <matthewmoppett at gmail.com> wrote:
>> Hi Sok Ha.
>>
>> expr = show send ++ "+" ++ show more ++ "=" show money
>>
>>
>>
>> On Sun, Jan 26, 2014 at 7:16 PM, Sok Ha Chang <shaegis at gmail.com> wrote:
>> > Hi.
>> > I’m new to Haskell.
>> > Use Haskell Platform on MacBook Air.
>> > $ ghc --version
>> > The Glorious Glasgow Haskell Compilation System, version 7.6.3
>> >
>> > I’m try to solve alphametic.
>> > SEND + MORE = MONEY
>> >
>> > Here is code…
>> > ----------------------------------------------------------------------------------------------------------
>> > import Data.List
>> >
>> > decryp :: [Int] -> String -> String
>> > decryp (s:e:n:d:o:r:y:[]) a =
>> > if send + more == money then expr:a else a
>> > where
>> > send = s * 1000 + e * 100 + n * 10 + d
>> > more = 1000 + o * 100 + r * 10 + e
>> > money = 10000 + o * 1000 + n * 100 + e * 10 + y
>> > expr = show send ++ "+" ++ show more ++ "=" show money
>> >
>> > decrypSolver :: [String]
>> > decrypSolver =
>> > foldr decryp [] (permutations 7 [0, 2, 3, 4, 5, 6, 7, 8, 9])
>> > ----------------------------------------------------------------------------------------------------------
>> >
>> > Error Messages is
>> > ./decrypSolver.hs: line 10, column 60:
>> > Couldn't match expected type `(a0 -> String) -> Int -> [Char]'
>> > with actual type `[Char]'
>> > The function `"="' is applied to two arguments,
>> > but its type `[Char]' has none
>> > In the second argument of `(++)', namely `"=" show money'
>> > In the second argument of `(++)', namely
>> > `show more ++ "=" show money’
>> > ----------------------------------------------------------------------------------------------------------
>> >
>> > How can I fix this?
>> >
>> > Thank you.
>> >
>> > Sincerely, S. Chang
>> > _______________________________________________
>> > Beginners mailing list
>> > Beginners at haskell.org
>> > http://www.haskell.org/mailman/listinfo/beginners
>
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