Learn Physics の導入

Learn Physics

learn-physics: Haskell code for learning physics

stackでインストールしてみます。

bar:graphics foo$ stack new graphics-work01
Downloading template "new-template" to create project "graphics-work01" in graphics-work01/ ...

The following parameters were needed by the template but not provided: author-email, author-name, category, copyright, github-username
You can provide them in /Users/foo/.stack/config.yaml, like this:
templates:
  params:
    author-email: value
    author-name: value
    category: value
    copyright: value
    github-username: value
Or you can pass each one as parameters like this:
stack new graphics-work01 new-template -p "author-email:value" -p "author-name:value" -p "category:value" -p "copyright:value" -p "github-username:value"

Looking for .cabal or package.yaml files to use to init the project.
Using cabal packages:
- graphics-work01/graphics-work01.cabal

Selecting the best among 10 snapshots...

Downloaded lts-8.11 build plan.
Fetching package index ...remote: Counting objects: 6105, done.
remote: Compressing objects: 100% (4824/4824), done.
remote: Total 6105 (delta 1641), reused 5005 (delta 1120), pack-reused 0
Receiving objects: 100% (6105/6105), 1.80 MiB | 2.27 MiB/s, done.
Resolving deltas: 100% (1641/1641), completed with 677 local objects.
From https://github.com/commercialhaskell/all-cabal-hashes
 + 94fd2e6...dbe78f6 hackage    -> origin/hackage  (forced update)
 - [tag update]      current-hackage -> current-hackage
Fetched package index.
Populated index cache.
Did not find .cabal file for unbounded-delays-0.1.0.10 with Git SHA of f02d37e48a454a6d91bbc9106222ea7fdd7764d2
Right Nothing
* Matches lts-8.11

Selected resolver: lts-8.11
Initialising configuration using resolver: lts-8.11
Total number of user packages considered: 1
Writing configuration to file: graphics-work01/stack.yaml
All done.

Cabalの編集

executable graphics-work01-exe
  hs-source-dirs:      app
  main-is:             Main.hs
  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
  build-depends:       base
                     , graphics-work01
                     , learn-physics

stack.yamlの編集をします。

# Dependency packages to be pulled from upstream that are not in the resolver
# (e.g., acme-missiles-0.3)
extra-deps: [
      learn-physics-0.6.0.2
    , not-gloss-0.7.7.0
    , spatial-math-0.2.7.0
]

上記のstack.yamlの設定をしないでstack buildすると、エラーとなります。

bar:graphics-work01 foo$ stack build
While constructing the BuildPlan the following exceptions were encountered:

--  Failure when adding dependencies:
      learn-physics: needed (-any), stack configuration has no specified version (latest applicable is 0.6.0.2)
    needed for package graphics-work01-0.1.0.0

--  While attempting to add dependency,
    Could not find package learn-physics in known packages

Recommended action: try adding the following to your extra-deps in /Users/foo/work03/graphics/graphics-work01/stack.yaml
- learn-physics-0.6.0.2

You may also want to try the 'stack solver' command

このエラーを解決するにはstack solverを実行します。そうすると、修正方法を教えてくれます。これが上述の設定になります。

bar:graphics-work01 foo$ stack solver
Using configuration file: stack.yaml
Using cabal packages:
- graphics-work01.cabal

Using resolver: lts-8.11
Using compiler: ghc-8.0.2
Asking cabal to calculate a build plan...
Trying with packages from lts-8.11 as hard constraints...
Successfully determined a build plan with 3 external dependencies.

The following changes will be made to stack.yaml:
* Resolver is lts-8.11
* Dependencies to be added
    extra-deps:
    - learn-physics-0.6.0.2
    - not-gloss-0.7.7.0
    - spatial-math-0.2.7.0

To automatically update stack.yaml, rerun with '--update-config'

初回のstack buildで依存関係を解決したライブラリがインストールされます。

bar:graphics-work01 foo$ stack build
graphics-work01-0.1.0.0: unregistering (missing dependencies: learn-physics)
ObjectName-1.1.0.1: download
ObjectName-1.1.0.1: configure

途中省略[f:id:naotoogawa:20170416134218p:plain]

learn-physics-0.6.0.2: build
learn-physics-0.6.0.2: copy/register
graphics-work01-0.1.0.0: configure
Configuring graphics-work01-0.1.0.0...
graphics-work01-0.1.0.0: build
Preprocessing library graphics-work01-0.1.0.0...
[1 of 1] Compiling Lib              ( src/Lib.hs, .stack-work/dist/x86_64-osx/Cabal-1.24.2.0/build/Lib.o )
ld: warning: directory not found for option '-L/opt/local/lib/'
Preprocessing executable 'graphics-work01-exe' for graphics-work01-0.1.0.0...
[1 of 1] Compiling Main             ( app/Main.hs, .stack-work/dist/x86_64-osx/Cabal-1.24.2.0/build/graphics-work01-exe/graphics-work01-exe-tmp/Main.o ) [Lib changed]
Linking .stack-work/dist/x86_64-osx/Cabal-1.24.2.0/build/graphics-work01-exe/graphics-work01-exe ...
ld: warning: directory not found for option '-L/opt/local/lib/'
graphics-work01-0.1.0.0: copy/register
Installing library in
/Users/foo/work03/graphics/graphics-work01/.stack-work/install/x86_64-osx/lts-8.11/8.0.2/lib/x86_64-osx-ghc-8.0.2/graphics-work01-0.1.0.0-Df1PA4o0N7R3GcxbM23sV6
Installing executable(s) in
/Users/foo/work03/graphics/graphics-work01/.stack-work/install/x86_64-osx/lts-8.11/8.0.2/bin
Registering graphics-work01-0.1.0.0...
Completed 61 action(s).
bar:graphics-work01 foo$ ls

サンプルを取得します。

bar:app foo$ curl -O https://raw.githubusercontent.com/walck/learn-physics/master/examples/src/LorentzForceSimulation.hs
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1464  100  1464    0     0   4636      0 --:--:-- --:--:-- --:--:--  4647
bar:app foo$ ls
LorentzForceSimulation.hs   Main.hs             eFieldLine2D.hs
bar:app foo$

cabalファイルに、main関数があるファイルの指定と、依存関係ライブラリの指定を追加します。

executable graphics-work01-exe
  hs-source-dirs:      app
  main-is:             LorentzFoArceSimulation.hs
  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
  build-depends:       base
                     , graphics-work01
                     , learn-physics
                     , not-gloss
                     , spatial-math
                     , gloss
  default-language:    Haskell2010

ビルドします。

bar:graphics-work01 foo$ stack build
graphics-work01-0.1.0.0: build
Preprocessing library graphics-work01-0.1.0.0...
Preprocessing executable 'graphics-work01-exe' for graphics-work01-0.1.0.0...
[1 of 1] Compiling Main             ( app/LorentzForceSimulation.hs, .stack-work/dist/x86_64-osx/Cabal-1.24.2.0/build/graphics-work01-exe/graphics-work01-exe-tmp/Main.o )
Linking .stack-work/dist/x86_64-osx/Cabal-1.24.2.0/build/graphics-work01-exe/graphics-work01-exe ...
ld: warning: directory not found for option '-L/opt/local/lib/'
graphics-work01-0.1.0.0: copy/register
Installing library in
/Users/foo/work03/graphics/graphics-work01/.stack-work/install/x86_64-osx/lts-8.11/8.0.2/lib/x86_64-osx-ghc-8.0.2/graphics-work01-0.1.0.0-Jws64xXpAJx1AXCetAcS6y
Installing executable(s) in
/Users/foo/work03/graphics/graphics-work01/.stack-work/install/x86_64-osx/lts-8.11/8.0.2/bin
Registering graphics-work01-0.1.0.0...

実行します。

bar:graphics-work01 foo$ stack exec graphics-work01-exe
bar:graphics-work01 foo$