[racket] Arity check

From: Roman Klochkov (kalimehtar at mail.ru)
Date: Wed Aug 21 04:16:52 EDT 2013

Why racket doesn't check arity when compiling?

(define (test)
  (car 12 3))

compiles and even runs. Ir raises an error only when test is called.

I can have desirable result making

(define-syntax car*
   (λ (stx)
     (syntax-case stx ()
       [(car* x) (syntax-protect (syntax/loc stx (car x)))]
       [(car* x ...) (raise-argument-error 'car "one argument" (syntax->datum #'(x ...)))]
       [car* (syntax-protect (syntax/loc stx car))]))))
(define (test)
  (car* 12 3))

But it is cumbersome (I'll have to wrap every function) and I don't understand why compiler shouldn't see function contracts.

Roman Klochkov
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