创建 Elixir 项目

$ mix new simple_statistics
$ cd simple_statistics
$ mix test

Mix 生成了如下目录结构

|-- _build
|-- config/|-- config.exs
|-- lib/|-- simple_statistics.ex
|-- test/|-- simple_statistics_test.exs|-- test_helper.exs
|-- mix.exs
|-- mix.lock
|-- README.md
|-- .gitignore

开发代码

在 lib 下创建 simple_statistics 子目录, 和包名称一样, 用于存放其他模块.

|-- lib/|-- simple_statistics/|-- mean.ex|-- simple_statistics.ex

# lib/simple_statistics/mean.ex
defmodule SimpleStatistics.Mean dodef mean([]), do: nildef mean(list) doEnum.sum(list) / Kernel.length(list)end
end

编写文档

使用 @moduledoc 和 @doc 编写函数和模块的文档. 应该在模块中编写每一个主要函数的文档.

# lib/simple_statistics/mean.ex
defmodule SimpleStatistics.Mean do@moduledoc false@doc ~S"""The mean is the sum of all values over the number of values."""def mean([]), do: nildef mean(list) doEnum.sum(list) / Kernel.length(list)end
end

添加文档测试

# lib/simple_statistics/mean.ex
defmodule SimpleStatistics.Mean do@moduledoc false@doc ~S"""The mean is the sum of all values over the number of values.## Examplesiex> SimpleStatistics.Mean.mean([])niliex> SimpleStatistics.Mean.mean([1,2,3,4,5])3.0iex> SimpleStatistics.Mean.mean([1.5,-2.1,3,4.5,5])2.38"""def mean([]), do: nildef mean(list) doEnum.sum(list) / Kernel.length(list)end
end

把 doctest 添加到测试集

# test/simple_statistics_test.ex
defmodule SimpleStatisticsTest douse ExUnit.Casedoctest SimpleStatistics.Mean
end

运行测试 mix test

$ mix test
.Finished in 0.07 seconds (0.07s on load, 0.00s on tests)
1 test, 0 failures

添加类型注解

类型注解可以使用 dialyzer 进行静态分析.

@spec mean(nonempty_list(number)) :: float()
def mean(list) doEnum.sum(list) / Kernel.length(list)
end

更新 mix.exs 文件, 添加依赖:

defp deps do[{:ex_doc, "~> 0.11", only: :dev},{:earmark, "~> 0.1", only: :dev},{:dialyxir, "~> 0.3", only: [:dev]}]
end

运行 dialyzer 静态分析工具:

$ mix dialyzer
Starting Dialyzer
dialyzer --no_check_plt --plt /Users/yosriady/.dialyxir_core_18_1.2.0.plt -Wunmatched_returns -Werror_handling -Wrace_conditions -Wunderspecs /Users/yosriady/simple_statistics/_build/dev/lib/simple_statistics/ebinProceeding with analysis... done in 0m1.68s
done (passed successfully)

生成文档

添加如下依赖到 mix.exs 文件

defp deps do[{:ex_doc, "~> 0.11", only: :dev},{:earmark, "~> 0.1", only: :dev}]
end

运行 mix deps.get 和 mix deps.compile 获取和安装这些依赖, 最后用 mix docs 生成文档:

$ mix docs
$ cd docs
$ open index.html

发布库

现在这边把开发好的库发布到Hex, 以方便自己和别人使用.

注册Hex用户账号

$ mix hex.user register

更具提示注册即可. 稍后会受到激活链接, 点击激活, 就可以登陆了.

设置项目元数据

# mix.exs
def project do[app: :decision_tree,version: "0.0.1",elixir: "~> 1.2",build_embedded: Mix.env == :prod,start_permanent: Mix.env == :prod,description: description,package: package,deps: deps]
enddefp description do"""A few sentences (a paragraph) describing the project."""
enddefp package do[files: ["lib", "mix.exs", "README.md"],maintainers: ["Yos Riady"],licenses: ["Apache 2.0"],links: %{"GitHub" => "https://github.com/Leventhan/simple_statistics","Docs" => "http://hexdocs.pm/simple_statistics/"}]
end

元数据和依赖添加到 mix.exs 文件后, 我们就准备好发布这个包了, 使用 mix hex.publish 发布:

$ mix hex.publish
Publishing simple_statistics 0.0.1Dependencies:Files:lib/simple_statistics.exlib/simple_statistics/mean.exmix.exsREADME.mdApp: simple_statisticsName: simple_statisticsDescription: Statistics toolkit for Elixir.Version: 0.0.1Build tools: mixLicenses: Apache 2.0Maintainers: Yos RiadyLinks:Docs: http://hexdocs.pm/simple_statistics/GitHub: https://github.com/Leventhan/simple_statisticsElixir: ~> 1.2WARNING! Excluded dependencies (not part of the Hex package):ex_docearmarkdialyxir
Before publishing, please read Hex Code of Conduct: https://hex.pm/docs/codeofconduct
[#########################] 100%
Published at https://hex.pm/packages/simple_statistics/0.0.1
Don't forget to upload your documentation with `mix hex.docs`

现在我们的库就已经发布为 mix.exs 中指定的版本了.

在一个小时内, 一个发布版本可以通过 --revert 参数进行修改或退回(取消这个版本的发布).
如果你想回退(revert)超过一小时的发布, 需要联系管理员

发布文档

可以把文档发布到 Hex Docs, 文档可以用任务 mix docs 生成.

$ mix hex.docs
Docs successfully generated.
View them at "doc/index.html".
[#########################] 100%
Published docs for simple_statistics 0.0.1
Hosted at https://hexdocs.pm/simple_statistics/0.0.1

文档可以通过 https://hexdocs.pm/simple_statistics/0.0.1 查看, https://hexdocs.pm/simple_statistics 总是重定向到最新的发布版本.

版本化

可以通过修改 mix.exs 文件的 version 值, 并运行 mix hex.publish 发布一个新的版本.

注意, 使用 Git tags 标注版本变更!

$ git tag -a v0.0.1 -m "Version 0.0.1"
$ git push origin v0.0.1 

结语

现在已经成功开发和发布了一个版本! 开发和发布Elixir库是简单和直接的. 现在其他开发者就可以把你的库添加到他们自己项目的依赖了.