44 lines
1.5 KiB
Racket
44 lines
1.5 KiB
Racket
#lang web-server
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(require web-server/managers/lru)
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(define-native (build-list/native _ ho) build-list)
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(define interface-version 'stateless)
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(define manager
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(make-threshold-LRU-manager #f (* 1024 1024 128)))
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(provide start interface-version manager)
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;; get-number-from-user: number -> number
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;; ask the user for a number
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(define (get-number-from-user message)
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(let ([req
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(send/suspend/url
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(lambda (k-url)
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`(html (head (title ,message))
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(body
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(form ([action ,(url->string k-url)]
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[method "post"]
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[enctype "application/x-www-form-urlencoded"])
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,message
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(input ([type "text"] [name "number"] [value ""]))
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(input ([type "submit"])))))))])
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(string->number
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(bytes->string/utf-8
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(binding:form-value
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(bindings-assq #"number"
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(request-bindings/raw req)))))))
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(define (start initial-request)
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(define how-many-numbers
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(get-number-from-user "How many numbers do you want to add?"))
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`(html (head (title "Final Page"))
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(body
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(h1 "Final Page")
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(p ,(format "The answer is ~a"
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(apply +
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(build-list/native how-many-numbers
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(lambda (i)
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(get-number-from-user
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(format "Enter number ~a" (add1 i)))))))))))
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