実践Haskell HTTPリクエストの作成 HTTP.Simpleモジュールを使用する getResponseHeaders関数
入門Haskellプログラミング (Will Kurt(著)、株式会社クイープ(監修、翻訳)、翔泳社)のUNIT7(実践Haskell)、LESSON39(HaskellでのHTTPリクエストの作成)、39.2(HTTP.Simpleモジュールを使用する)、クイックチェック 39-2の解答を求めてみる。
package.yaml
name: http-lesson
version: 0.1.0.0
github: "githubuser/http-lesson"
license: BSD3
author: "Author name here"
maintainer: "example@example.com"
copyright: "2022 Author name here"
extra-source-files:
- README.md
- ChangeLog.md
# Metadata used when publishing your package
# synopsis: Short description of your package
# category: Web
# To avoid duplicated efforts in documentation and dealing with the
# complications of embedding Haddock markup inside cabal files, it is
# common to point users to the README.md file.
description: Please see the README on GitHub at <https://github.com/githubuser/http-lesson#readme>
dependencies:
- base >= 4.7 && < 5
library:
source-dirs: src
executables:
http-lesson-exe:
main: Main.hs
source-dirs: app
ghc-options:
- -threaded
- -rtsopts
- -with-rtsopts=-N
dependencies:
- http-lesson
- bytestring
- http-conduit
default-extensions: OverloadedStrings
tests:
http-lesson-test:
main: Spec.hs
source-dirs: test
ghc-options:
- -threaded
- -rtsopts
- -with-rtsopts=-N
dependencies:
- http-lesson
コード
Main.hs
module Main where
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as BC
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Lazy.Char8 as LC
import Network.HTTP.Simple
response :: IO (Response LC.ByteString)
response = httpLBS "http://news.ycombinator.com"
main :: IO ()
main = do
res <- response
print $ getResponseHeaders res
入出力結果(Terminal, Zsh)
% stack ghci
Using main module: 1. Package `http-lesson' component http-lesson:exe:http-lesson-exe with main-is file: /Users/…/http-lesson/app/Main.hs
http-lesson> initial-build-steps (lib + exe)
The following GHC options are incompatible with GHCi and have not been passed to it: -threaded
Configuring GHCi with the following packages: http-lesson
* * * * * * * *
Warning: Multiple files use the same module name:
* Paths_http_lesson found at the following paths
* /Users/…/http-lesson/.stack-work/dist/x86_64-osx/Cabal-3.4.1.0/build/autogen/Paths_http_lesson.hs (http-lesson:lib)
* /Users/…/http-lesson/.stack-work/dist/x86_64-osx/Cabal-3.4.1.0/build/http-lesson-exe/autogen/Paths_http_lesson.hs (http-lesson:exe:http-lesson-exe)
* * * * * * * *
GHCi, version 9.0.2: https://www.haskell.org/ghc/ :? for help
:macro 'doc' overwrites builtin command. Use ':def!' to overwrite.
(0.00 secs, 0 bytes)
(0.00 secs, 0 bytes)
Loaded GHCi configuration from /Users/…/.ghc/ghci.conf
[1 of 3] Compiling Lib ( /Users/…/http-lesson/src/Lib.hs, interpreted )
[2 of 3] Compiling Main ( /Users/…/http-lesson/app/Main.hs, interpreted )
l[3 of 3] Compiling Paths_http_lesson ( /Users/…/http-lesson/.stack-work/dist/x86_64-osx/Cabal-3.4.1.0/build/autogen/Paths_http_lesson.hs, interpreted )
Ok, three modules loaded.
Loaded GHCi configuration from /private/var/folders/2y/nfx9b0d9267fxn7rhzybw2xh0000gn/T/haskell-stack-ghci/b501d9c1/ghci-script
*Main Lib Paths_http_lesson
λ> :load app/Main.hs
[1 of 1] Compiling Main ( app/Main.hs, interpreted )
Ok, one module loaded.
(0.02 secs,)
*Main
λ> getRe
getRequestHeader getResponseHeader getResponseStatusCode
getRequestQueryString getResponseHeaders
getResponseBody getResponseStatus
λ> getResponseHeaders <$> response
[("Server","nginx"),("Date","Tue, 29 Mar 2022 03:22:57 GMT"),("Content-Type","text/html; charset=utf-8"),("Transfer-Encoding","chunked"),("Connection","keep-alive"),("Vary","Accept-Encoding"),("Cache-Control","private; max-age=0"),("X-Frame-Options","DENY"),("X-Content-Type-Options","nosniff"),("X-XSS-Protection","1; mode=block"),("Referrer-Policy","origin"),("Strict-Transport-Security","max-age=31556900"),("Content-Security-Policy","default-src 'self'; script-src 'self' 'unsafe-inline' https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://cdnjs.cloudflare.com/; frame-src 'self' https://www.google.com/recaptcha/; style-src 'self' 'unsafe-inline'; img-src 'self' https://account.ycombinator.com"),("Content-Encoding","gzip")]
it ::
[(http-types-0.12.3:Network.HTTP.Types.Header.HeaderName,
BC.ByteString)]
(1.22 secs, 2,820,232 bytes)
*Main
λ> res <- response
res :: Response LC.ByteString
(0.28 secs, 870,424 bytes)
*Main
λ> getResponseHeaders res
[("Server","nginx"),("Date","Tue, 29 Mar 2022 03:23:09 GMT"),("Content-Type","text/html; charset=utf-8"),("Transfer-Encoding","chunked"),("Connection","keep-alive"),("Vary","Accept-Encoding"),("Cache-Control","private; max-age=0"),("X-Frame-Options","DENY"),("X-Content-Type-Options","nosniff"),("X-XSS-Protection","1; mode=block"),("Referrer-Policy","origin"),("Strict-Transport-Security","max-age=31556900"),("Content-Security-Policy","default-src 'self'; script-src 'self' 'unsafe-inline' https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://cdnjs.cloudflare.com/; frame-src 'self' https://www.google.com/recaptcha/; style-src 'self' 'unsafe-inline'; img-src 'self' https://account.ycombinator.com"),("Content-Encoding","gzip")]
it ::
[(http-types-0.12.3:Network.HTTP.Types.Header.HeaderName,
BC.ByteString)]
(0.05 secs, 1,222,496 bytes)
*Main
λ> main
[("Server","nginx"),("Date","Tue, 29 Mar 2022 03:23:25 GMT"),("Content-Type","text/html; charset=utf-8"),("Transfer-Encoding","chunked"),("Connection","keep-alive"),("Vary","Accept-Encoding"),("Cache-Control","private; max-age=0"),("X-Frame-Options","DENY"),("X-Content-Type-Options","nosniff"),("X-XSS-Protection","1; mode=block"),("Referrer-Policy","origin"),("Strict-Transport-Security","max-age=31556900"),("Content-Security-Policy","default-src 'self'; script-src 'self' 'unsafe-inline' https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://cdnjs.cloudflare.com/; frame-src 'self' https://www.google.com/recaptcha/; style-src 'self' 'unsafe-inline'; img-src 'self' https://account.ycombinator.com"),("Content-Encoding","gzip")]
it :: ()
(0.29 secs, 1,547,696 bytes)
*Main
λ> :quit
Leaving GHCi.
%