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IT練習ノート

IT関連で調べたこと(実際は嵌ったこと)を書いています。

Servantのexampleのcabalファイルを作成する

下記にあるexampleのgreet.hs用のcabalファイルを作ります。

github.com

cabal initにて対話形式で必要な項目を入力していきます。

 foo$ cabal init
Package name? [default: servant02] greet
Package version? [default: 0.1.0.0] 
Please choose a license:
   1) GPL-2
   2) GPL-3
   3) LGPL-2.1
   4) LGPL-3
   5) AGPL-3
   6) BSD2
 * 7) BSD3
   8) MIT
   9) ISC
  10) MPL-2.0
  11) Apache-2.0
  12) PublicDomain
  13) AllRightsReserved
  14) Other (specify)
Your choice? [default: BSD3] 8
Author name? [default: bar] foo
Maintainer email? [default: aaa@gmail.com] foo@gmail.com
Project homepage URL? 
Project synopsis? greet
Project category:
 * 1) (none)
   2) Codec
   3) Concurrency
   4) Control
   5) Data
   6) Database
   7) Development
   8) Distribution
   9) Game
  10) Graphics
  11) Language
  12) Math
  13) Network
  14) Sound
  15) System
  16) Testing
  17) Text
  18) Web
  19) Other (specify)
Your choice? [default: (none)] 18
What does the package build:
   1) Library
   2) Executable
Your choice? 2
What is the main module of the executable:
 * 1) Main.hs
   2) Other (specify)
Your choice? [default: Main.hs] 2
Please specify? greet.hs
Source directory:
 * 1) (none)
   2) src
   3) Other (specify)
Your choice? [default: (none)] 
What base language is the package written in:
 * 1) Haskell2010
   2) Haskell98
   3) Other (specify)
Your choice? [default: Haskell2010] 
Add informative comments to each field in the cabal file (y/n)? [default: n] y

Guessing dependencies...

Generating LICENSE...
Warning: LICENSE already exists, backing up old version in LICENSE.save0
Generating Setup.hs...
Warning: Setup.hs already exists, backing up old version in Setup.hs.save0
Generating ChangeLog.md...
Warning: ChangeLog.md already exists, backing up old version in ChangeLog.md.save0
Generating greet.cabal...

You may want to edit the .cabal file and add a Description field.

そのまま実行しようとすると、依存関係のライブラリの指定がなくてエラーになります。Guessing dependencies...とありますが、完全には推測してくれないようです。

 foo$ cabal run greet.cabal 
./greet.cabal has been changed. Re-configuring with most recently used
options. If this fails, please run configure manually.
Resolving dependencies...
Configuring greet-0.1.0.0...
Preprocessing executable 'greet' for greet-0.1.0.0...
[1 of 1] Compiling Main             ( greet.hs, dist/build/greet/greet-tmp/Main.o ) [Servant changed]

greet.hs:8:1: error:
    Failed to load interface for ‘Data.Aeson’
    It is a member of the hidden package ‘aeson-1.0.2.1’.
    Perhaps you need to add ‘aeson’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

greet.hs:11:1: error:
    Failed to load interface for ‘Data.Text’
    It is a member of the hidden package ‘text-1.2.2.1’.
    Perhaps you need to add ‘text’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

greet.hs:13:1: error:
    Failed to load interface for ‘Network.Wai’
    It is a member of the hidden package ‘wai-3.2.1.1’.
    Perhaps you need to add ‘wai’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

greet.hs:14:1: error:
    Failed to load interface for ‘Network.Wai.Handler.Warp’
    It is a member of the hidden package ‘warp-3.2.9’.
    Perhaps you need to add ‘warp’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

greet.hs:16:1: error:
    Failed to load interface for ‘Servant’
    It is a member of the hidden package ‘servant-server-0.9.1.1’.
    Perhaps you need to add ‘servant-server’ to the build-depends in your .cabal file.
    Use -v to see a list of the files searched for.

生成されたgreet.cabalファイルに、下記の部分を追加しました。バージョンは省いています。

 59   -- Other library packages from which modules are imported.
 60   build-depends:       base >=4.9 && <4.10,   -- カンマを追加
 61                        aeson,                 -- 追加
 62                        text,                  -- 追加
 63                        wai,                   -- 追加
 64                        warp,                  -- 追加
 65                        servant-server         -- 追加

実行します。

 foo$ cabal run greet.cabal 
./greet.cabal has been changed. Re-configuring with most recently used
options. If this fails, please run configure manually.
Resolving dependencies...
Configuring greet-0.1.0.0...
Preprocessing executable 'greet' for greet-0.1.0.0...
Running greet...
^C
 foo$ 

最終的なファイルは下記です。

gist.github.com