Question

这个程序是关于计算单词，但它在标题中给出错误，我无法解决它。它说未找到的编译器并要求我使用-v，但这也会出错。我需要为矢量使用哪些其他文件？

这是我正在尝试编译的代码：

{-# LANGUAGE BangPatterns, MagicHash #-}

import qualified Data.Vector.Unboxed as VU
import Data.Vector.Unboxed ((!))
import qualified Data.Vector.Generic as VG --this one 
import GHC.Base (Int(..), quotInt#, remInt#)

ones, tens, teens :: [String]
ones = ["", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
tens = ["", "ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
teens = ["ten", "eleven", "twelve", "thirteen",
 "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]

wordify :: Int -> String
wordify n
    | n < 10         = ones !! n
    | n < 20         = teens !! (n-10)
    | n < 100        = splitterTen
    | n < 1000       = splitter 100 "hundred"
    | n < 1000000    = splitter 1000 "thousand"
    | otherwise      = splitter 1000000 "million"
      where 
         splitterTen = let (t, x) = n `quotRem` 10 
                       in (tens !! t) ++ wordify x
         splitter d suffix = let (t, x) = n `quotRem` d
                             in (wordify t) ++ suffix ++ wordify x

wordLength :: Int -> Int
wordLength i = go 0 i
  where
    go !pad !n
        | n < 10         = lenOnes `VG.unsafeIndex` n + pad
        | n < 20         = lenTeens `VG.unsafeIndex` (n-10) + pad
        | n < 100        = go (lenTens `VG.unsafeIndex` (n//10) + pad) (n%10)
        | n < 1000       = go (go (7+pad) (n//100)) (n%100)
        | n < 1000000    = go (go (8+pad) (n//1000)) (n%1000)
        | otherwise      = go (go (7+pad) (n//1000000)) (n%1000000)

    (I# a) // (I# b) = I# (a `quotInt#` b)
    (I# a) % (I# b) = I# (a `remInt#` b)
    !lenOnes = VU.fromList [0,3,3,5,4,4,3,5,5,4] -- "", "one","two", ...
    !lenTens = VU.fromList [0,3,6,6,5,5,5,7,6,6]
    !lenTeens = VU.fromList [3,6,6,8,8,7,7,9,8,8] -- first element is "ten" 3

Answer 1

好像你

小姐延期
有缩进缩进

这是一个固定版本：

{-# LANGUAGE MagicHash, BangPatterns #-}

import qualified Data.Vector.Unboxed as VU
import Data.Vector.Unboxed ((!))
import qualified Data.Vector.Generic as VG --this once 
import GHC.Base (Int(..), quotInt#, remInt#)

ones, tens, teens :: [String]
ones = ["", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
tens = ["", "ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
teens = ["ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eig  hteen", "nineteen"]

wordify :: Int -> String
wordify n
 | n < 10         = ones !! n
 | n < 20         = teens !! (n-10)
 | n < 100        = splitterTen
 | n < 1000       = splitter 100 "hundred"
 | n < 1000000    = splitter 1000 "thousand"
 | otherwise      = splitter 1000000 "million"
  where
   splitterTen = let (t, x) = n `quotRem` 10 
    in (tens !! t) ++ wordify x
   splitter d suffix = let (t, x) = n `quotRem` d
    in (wordify t) ++ suffix ++ wordify x

wordLength :: Int -> Int
wordLength i = go 0 i
  where
   go !pad !n
    | n < 10         = lenOnes `VG.unsafeIndex` n + pad
    | n < 20         = lenTeens `VG.unsafeIndex` (n-10) + pad
    | n < 100        = go (lenTens `VG.unsafeIndex` (n//10) + pad) (n%10)
    | n < 1000       = go (go (7+pad) (n//100)) (n%100)
    | n < 1000000    = go (go (8+pad) (n//1000)) (n%1000)
    | otherwise      = go (go (7+pad) (n//1000000)) (n%1000000)

   (I# a) // (I# b) = I# (a `quotInt#` b)
   (I# a) % (I# b) = I# (a `remInt#` b)
   !lenOnes = VU.fromList [0,3,3,5,4,4,3,5,5,4] -- "", "one","two", ...
   !lenTens = VU.fromList [0,3,6,6,5,5,5,7,6,6]
   !lenTeens = VU.fromList [3,6,6,8,8,7,7,9,8,8] -- first element is "ten" 3

注意开头的固定缩进和LANGUAGE pragma表示您使用两种非标准语言扩展。

您可以运行ghc-pkg vector，如果它没有说出vector-0.9.1之类的内容，那么您需要运行cabal update，然后运行cabal install vector。

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1 个答案: