r markdown - How can I register Racket engine in knit and rmarkdown?

Question

I installed Racket (https://racket-lang.org/) on windows 10 and added the Racket folder into the Enviroment Variables "Path". I tried to use Racket code in Rmarkdown and I have to register Racket engine in knit:

knitr::knit_engines$set(Racket = function(options) {
  code <- paste(options$code, collapse = '
')
  out  <- system2(
    'Racket', shQuote(code), stdout = TRUE
  )
  knitr::engine_output(options, code, out)
})

Then I wrote Racket code in Rmarkdown:

{Racket, engine.path='~/Racket/Racket', stdout=TRUE}
#lang sicp
(define (inc x) (+ x 1))
(define (dec x) (- x 1))
(inc 6)

But it failed and showed "In get_engine(options$engine) : unknown language engine 'racket' (must be registered via knit_engines$set())". Who can tell me what is wrong with the registration of the Racket engine?

Answer 1

等待大神解答