如何在 ghci 提示符下不显示重复模块

Question

目前我的 ghci 提示是这样的：

而且我想这样做，这样我的提示就不会显示重复的模块，如下所示：

但我真的不知道怎么做。我的配置（ghci.conf）文件的内容如下所示：

:set +m

import qualified IPPrint
import qualified Language.Haskell.HsColour as HsColour
import qualified Language.Haskell.HsColour.Colourise as HsColour
import qualified Language.Haskell.HsColour.Output as HsColour

let myColourPrefs = HsColour.defaultColourPrefs { HsColour.conid = [HsColour.Foreground HsColour.Yellow, HsColour.Bold], HsColour.conop = [HsColour.Foreground HsColour.Yellow], HsColour.string = [HsColour.Foreground HsColour.Green], HsColour.char = [HsColour.Foreground HsColour.Cyan], HsColour.number = [HsColour.Foreground HsColour.Red, HsColour.Bold], HsColour.layout = [HsColour.Foreground HsColour.White], HsColour.keyglyph = [HsColour.Foreground HsColour.White] }

let myPrint = putStrLn . HsColour.hscolour (HsColour.TTYg HsColour.XTerm256Compatible) myColourPrefs False False "" False . IPPrint.pshow

:set -interactive-print=myPrint

:{
prompter :: [String] -> Int -> IO String
prompter modules line = return $
    concat [ "\ESC[33m\STX[Module(s): "
           -- this is the only line that changed
           , Data.List.intercalate ", " $ zipWith (\n m -> concat [show n, ".", m]) [1..] modules
           , "]\ESC[0m\STX\n \ESC[38;5;86m\STX\x03BB > \ESC[0m\STX"
           ]   
:}
:set prompt-function prompter
clear = putStr "\ESC[2J\ESC[H"

提前致谢。

Answer 1

通过使用 nub 从列表中删除重复元素（参见：https://hoogle.haskell.org/?hoogle=nub），我能够从模块列表中删除重复元素，如下所示：

为此，还必须将代码修改为：

:{
prompter :: [String] -> Int -> IO String
prompter modules line = return $
    concat [ "\ESC[33m\STX[Module(s): "
           -- this is the only line that changed
           , Data.List.intercalate ", " $ zipWith (\n m -> concat [show n, ".", m]) [1..] (nub modules)
           , "]\ESC[0m\STX\n \ESC[38;5;86m\STX\x03BB > \ESC[0m\STX"
           ]   
:}

并且由于 nub 是 Data.List 模块的一部分，我还必须包括：

import Data.List

如何在 ghci 提示符下不显示重复模块

How to not display duplicate modules on ghci prompt

haskell

prompt

ghci