82 lines
2.3 KiB
Racket
82 lines
2.3 KiB
Racket
#lang racket/base
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(require "../main.rkt")
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(provide usecase-random-number
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usecase-unique-values
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usecase-array-at
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usecase-sum-to
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usecase-make-adder
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usecase-set-html
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all-js-usecases
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show-js-usecases
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write-js-usecases-file)
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;; Use case 01: generate a random integer between 1 and 5.
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(define usecase-random-number
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(js
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(define (randomBetween1And5)
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(return (+ (send Math floor (* (send Math random) 5)) 1)))))
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;; Use case 02: get unique values from an array with duplicates using Set.
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(define usecase-unique-values
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(js
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(define (uniqueValues xs)
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(return (send Array from (new Set xs))))))
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;; Use case 03: indexed array access with js-ref.
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(define usecase-array-at
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(js
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(define (arrayAt xs i)
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(return (js-ref xs i)))))
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;; Use case 04: named let as a loop. The branch that leaves the loop uses an
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;; explicit return, because js-maker 3 is statement-oriented.
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(define usecase-sum-to
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(js
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(define (sumTo n)
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(let loop ([i 0] [acc 0])
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(if (> i n)
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(return acc)
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(loop (+ i 1) (+ acc i)))))))
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;; Use case 05: return a JavaScript function value.
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(define usecase-make-adder
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(js
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(define (makeAdder x)
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(return (lambda (y)
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(return (+ x y)))))))
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;; Use case 06: small DOM setter. It uses send, js-dot and set!.
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(define usecase-set-html
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(js
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(define (setHtml id html)
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(let ([el (send document getElementById id)])
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(set! (js-dot el innerHTML) html)
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(return (js-dot el innerHTML))))))
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(define all-js-usecases
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`((random-number . ,usecase-random-number)
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(unique-values . ,usecase-unique-values)
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(array-at . ,usecase-array-at)
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(sum-to . ,usecase-sum-to)
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(make-adder . ,usecase-make-adder)
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(set-html . ,usecase-set-html)))
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(define (show-js-usecases)
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(for ([entry (in-list all-js-usecases)])
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(displayln (format "// ~a" (car entry)))
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(displayln (cdr entry))
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(newline)))
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(define (write-js-usecases-file [path "demo/js-usecases.generated.js"])
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(call-with-output-file path #:exists 'replace
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(lambda (out)
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(for ([entry (in-list all-js-usecases)])
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(displayln (format "// ~a" (car entry)) out)
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(displayln (cdr entry) out)
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(newline out)))))
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(module+ main
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(show-js-usecases))
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