Elm:
基本認証を使用したHTTPリクエストの送信

import Http
import Base64

type alias Credentials =
    { username : String
    , password : String
    }

createBasicAuthHeader : Credentials -> Http.Header
createBasicAuthHeader creds =
    let
        encodedCredentials =
            Base64.encode (creds.username ++ ":" ++ creds.password)
    in
    Http.header "Authorization" ("Basic " ++ encodedCredentials)

-- Send a request with basic authentication
sendRequest : String -> Credentials -> Cmd msg
sendRequest url creds =
    let
        headers = 
            [ createBasicAuthHeader creds ]
    in
    Http.request
        { method = "GET"
        , headers = headers
        , url = url
        , body = Http.emptyBody
        , expect = Http.expectWhatever msg
        , timeout = Nothing
        , tracker = Nothing
        }

-- Example usage
login : Cmd msg
login =
    sendRequest "https://your-api.com/protected" { username = "user1", password = "pass123" }