如何获得ascii字符的值在haskell？ [英] How to get ascii value of character in haskell?

问题描述

只是想知道如何获得ascii字符的值在haskell？
我试图在ghci中使用'ord'函数，基于我在这里读取：

Just wondering how to get ascii value of character in haskell? I've tried to use the 'ord' function in ghci, based on what i read here:

http://haskell.org/ghc/docs/6.12。 2 / html / libraries / base-4.2.0.1 / Data-Char.html＃6

GHCi, version 6.12.1: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Prelude> ord 'a'

<interactive>:1:0: Not in scope: `ord'
Prelude>

我做错了什么？

推荐答案

由于 Travis Brown 在评论中指出，您必须导入 ord 函数 Data.Char ：

As Travis Brown indicated in a comment, you have to import the ord function from the module Data.Char:

import Data.Char (ord)

main = print (ord 'a')

只有 Prelude 模块默认加载，所有其他模块必须显式导入。

Only the Prelude module is loaded by default, all other modules have to be imported explicitly.

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