d61eb53686
Started as fixing misindented definitions, then more indentations, then a bunch of similar things (square brackets, huge spaces at end-of-lines, etc).
44 lines
2.0 KiB
Racket
44 lines
2.0 KiB
Racket
#lang scribble/doc
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@(require "web-server.rkt")
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@title[#:tag "servlet-structs"]{Responses}
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@(require (for-label web-server/servlet/servlet-structs
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web-server/http
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web-server/servlet))
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@defmodule[web-server/servlet/servlet-structs]{
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Servlets communicate to the Web Server by returning HTTP responses. In order to
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accommodate lightweight programs (and backwards compatibility), the Web Server
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provides an indirection from application-specific response formats and the internal
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HTTP response format, @racket[response].
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@deftogether[[
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@defproc[(can-be-response? [x any/c])
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boolean?]
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@defproc[(any->response [x any/c])
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(or/c false/c response?)]
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@defproc[(set-any->response! [new-any->response (-> any/c (or/c false/c response?))])
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void]
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]]{
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@racket[any->response] coerces any value into a response or returns @racket[#f] if coercion is not possible.
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@racket[any->response] guarantees that any @racket[response?] input must always be returned exactly (i.e. @racket[eq?].)
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The default always returns @racket[#f], signifying that no coercion is possible.
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@racket[can-be-response?] returns @racket[#t] if @racket[x] is a response or can be turned into a response by calling
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@racket[any->response].
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Users of @racket[any->response] should protect themselves by using @racket[can-be-response?] as a contract.
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If they do so, they can safely ignore the @racket[#f] return case of @racket[any->response].
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@racket[set-any->response!] replaces the global @racket[any->response] with the supplied argument. This
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function should return the same value for @racket[eq?] inputs to ensure that @racket[can-be-response?] is
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any accurate predicate. Similarly, this function should be cheap to call multiple times on the same input,
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since it will be used in contract checking as well as coercion before transmission. You may want to use a
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weak @racket[eq?]-based hash-table to cache the results for this purpose. (See @racket[make-weak-hasheq].)
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}
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}
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