haskell - 使用标准的类型错误

Question

我阅读了文档和一些讨论该包的文章，但我是 Haskell 的新手，不太了解，但我尝试过......

以下是我所做的:

module Main where  
{-# LANGUAGE BangPatterns #-}   
import Control.Parallel(par,pseq)  
import Control.Exception  
import Data.List  
import IO  
import Data.Char  
import Criterion.Main (defaultMain, bench)  

learquivo :: FilePath -> IO ([[Int]])  
learquivo "mkList1.txt"  = do   
    conteudo <- readFile "mkList1.txt" 
    return (read conteudo) 


main = defaultMain [  
    bench "map sort learquivo" $ \n -> map sort learquivo
    ]

当它执行时，发生以下错误:

Couldn't match expected type [[a]]
       against inferred type FilePath -> IO [[Int]]

Answer 1

为了让您了解我通常如何使用 nf 或 whnf 函数运行它，我将给出我的代码:

import Data.List
import Criterion.Main

main :: IO ()
main = do
   -- content <- learquivo "mkList1.txt"  
   let content = [ [big, big - step.. 0] | big <- [1000..1010], step <- [1..5]] :: [[Int]]
   defaultMain
        [ bench "benchmark-name" (nf (map sort) content)]

编辑:如果你喜欢这个，那么也尝试一下绘图:

module Main where

import Data.List
import Criterion.Main
import Criterion.Config
import Criterion.MultiMap as M

main :: IO ()
main = do
   let myConfig = defaultConfig {
              -- Always display an 800x600 window with curves.
              cfgPlot = M.singleton KernelDensity (Window 800 600)
              }
   let content = [ [big, big-step.. 0] | big <- [1000..1010], step <- [1..5]] :: [[Int]]
   defaultMainWith myConfig (return ())
        [ bench "benchmark-name" (nf (map sort) content)]