#lang scribble/manual

@(require (for-label racket/base js-maker))

@title{js-maker Use Cases}
@author+email["Hans Dijkema" "hans@dijkewijk.nl"]

@defmodule[js-maker/demo/js-usecases]

The demos in @filepath{demo/js-usecases.rkt} use only the public
@racket[js] macro and the compact js-maker 3 form set.  They are intentionally
small: their purpose is to show the supported surface language, not to recreate
the larger runtime-helper branch.

@section{Random number}

@codeblock{
(js
 (define (randomBetween1And5)
   (return (+ (send Math floor (* (send Math random) 5)) 1))))
}

@section{Unique values}

@codeblock{
(js
 (define (uniqueValues xs)
   (return (send Array from (new Set xs)))))
}

@section{Indexed access}

@codeblock{
(js
 (define (arrayAt xs i)
   (return (js-ref xs i))))
}

@section{Named let loop}

@codeblock{
(js
 (define (sumTo n)
   (let loop ([i 0] [acc 0])
     (if (> i n)
         (return acc)
         (loop (+ i 1) (+ acc i))))))
}

@section{Function value}

@codeblock{
(js
 (define (makeAdder x)
   (return (lambda (y)
             (return (+ x y))))))
}

@section{DOM setter}

@codeblock{
(js
 (define (setHtml id html)
   (let ([el (send document getElementById id)])
     (set! (js-dot el innerHTML) html)
     (return (js-dot el innerHTML)))))
}