如何从Haskell的列表中生成元素的随机序列?

本文介绍了如何从Haskell的列表中生成元素的随机序列?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我浏览了 hackage.haskell/package/random-1.1/docs/System-Random.html ，但是我看不到如何使用自定义列表"，例如 ['a'..'z'] ++ ['0'..'9'] ?

I've had a look through hackage.haskell/package/random-1.1/docs/System-Random.html however I can't see how to use a custom "list" for example an alphanumeric list of ['a'..'z'] ++ ['0' .. '9']?

我想作为一种解决方法，我可以改为映射一组随机数字.

I suppose as a workaround I could instead map a random set of numbers instead.

推荐答案

我提到的实现工作的实现:

The implementation of the work around I mentioned:

Prelude> import System.Random Prelude System.Random> gen <- newStdGen Prelude System.Random> x = ['a'..'z'] ++ ['0' .. '9'] Prelude System.Random> fmap (x !! ) (take 10 $ randomRs (0, length x - 1 ) gen) "h4tm52rfox"