32 lines
1.1 KiB
Racket
32 lines
1.1 KiB
Racket
#lang scribble/doc
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@(require scribble/manual "shared.rkt"
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(for-label racket teachpack/htdp/elevator))
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@teachpack["elevator"]{Controlling an Elevator}
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@;declare-exporting[teachpack/htdp/elevator]
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@defmodule[#:require-form beginner-require htdp/elevator]
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The teachpack implements an elevator simulator.
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It displays an eight-floor elevator and accepts mouse clicks from the user,
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which are translated into service demands for the elevator.
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@defproc[(run [NextFloor number?]) any/c]{Creates an elevator simulator
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that is controlled by @racket[NextFloor]. This function consumes the
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current floor, the direction in which the elevator is moving, and the
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current demands. From that, it computes where to send the elevator next.}
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Example: Define a function that consumes the current state of
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the elevator (three arguments) and returns a number between 1 and 8. Here
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is a non-sensical definition:
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@racketblock[(define (controller x y z) 7)]
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It moves the elevator once, to the 7th floor.
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Second, set the teachpack to @filepath{elevator.rkt}, click Run, and
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evaluate
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@racketblock[(run controller)]
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