haskell vscode下的环境搭配(包含各种坑的解决办法)

这可能是最傻瓜化的在vscode下的haskell配置介绍文章

为什么要写这篇文章？

在自己写搭建环境的过程中，搜了一些博文，有些真的及其不服责任和敷衍，草草几句话就带过，但是在google上排名还很高，带着一种鄙视这些文章的态度，于是写下这篇文章，希望给后面的人有帮助

安装haskell

我的平台：deepin-15.8，基于debian8，(ubuntu等应该没太大区别

这里是一份haskell的学习指南，粗略介绍了安装，资源等一些东西
根据上面链接的内容，我们可以得知：
不推荐使用Haskell-platform直接安装
也不太推荐使用cabel

更推荐使用stack安装
官网安装文档

安装

For many Un*x operating systems, all you need to do is run://对于unix类系统

curl -sSL https://get.haskellstack.org/ | sh

or:

wget -qO- https://get.haskellstack.org/ | sh

(对于windows系统)On Windows, you can download and install the Windows 64-bit Installer.

创建你的project:

stack new my-project
cd my-project
stack setup
stack build
stack exec my-project-exe

• The stack new command will create a new directory containing all the needed files to start a project correctly.
• The stack setup will download the compiler if necessary in an isolated location (default ~/.stack) that won't interfere with any system-level installations. (For information on installation paths, please use the stack path command.).
• The stack build command will build the minimal project.
• stack exec my-project-exe will execute the command.
• If you just want to install an executable using stack, then all you have to do is stack install <package-name>.

注意，linux系统最好将~/.local/bin加入PATH中

换源

毕竟源在国外，所以我们首先必须要进行换源，幸好清华大学开源网站镜像站有提供，更具体一点可以看Stackage 镜像使用说明，这里记录下

vim ~/.stack/config.yaml
# add
package-indices:
- name: Tsinghua
  download-prefix: https://mirrors.tuna.tsinghua.edu.cn/hackage/package/
  http: https://mirrors.tuna.tsinghua.edu.cn/hackage/00-index.tar.gz
setup-info: "http://mirrors.tuna.tsinghua.edu.cn/stackage/stack-setup.yaml"
urls:
  latest-snapshot: http://mirrors.tuna.tsinghua.edu.cn/stackage/snapshots.json
  lts-build-plans: http://mirrors.tuna.tsinghua.edu.cn/stackage/lts-haskell/
  nightly-build-plans: http://mirrors.tuna.tsinghua.edu.cn/stackage/stackage-nightly/
# 开始使用stack，这个命令需要稍稍等待
stack setup
# 安装完成之后
stack ghci
# 会出现以下输出
Configuring GHCi with the following packages:
GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /private/var/folders/0s/j3c0tlx10z9_x9wzhl14xmgh0000gn/T/ghci11066/ghci-script
Prelude>

搭建vscode

打开vscode，下载extension，这里我推荐这四个插件：Haskell Syntax Highlighting、Haskell ghc-mod 、haskell-linter、Haskelly，其中第四个插件离不开stack。
要想使用以上插件，必须安装以下几个包：

# for Haskell ghc-mod 
stack install ghc-mod
# for haskell-linter
stack install hlint
# for Haskelly
stack install intero
stack install QuickCheck
stack install stack-run

安装时可能出现问题

ghc-mod安装时如果报错

stackoverflow上的解决办法
我采用了
stack install ghc-mod --resolver lts-8.24去解决

stack-run安装报错

github issue

I found a workaround.

Create a file: ~/.stack/global-project/stack-cabal-1.24.yaml

flags: {}
extra-package-dbs: []
packages: []
extra-deps: []
resolver: lts-8.24

Basically it's using an old stack lts that was from around the time the last update to stack-run was >made.

Then just run this:

stack --stack-yaml ~/.stack/global-project/stack-cabal-1.24.yaml install stack-run

and it should work (did for me, at least)

intero安装报错

stack install --resolver lts-6.6 intero-0.1.15去解决

vscode 插件配置

然后打开vscode的配置文件，加上ghc-mod和hlint的路径，如下：

"haskell.ghcMod.executablePath": "/home/.local/bin/ghc-mod",
"haskell.hlint.executablePath": "/home/.local/bin/hlint"