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beautiful-racket/beautiful-racket-demo/basic-demo-3/misc.rkt

23 lines
691 B
Racket

#lang br
(require "struct.rkt" "expr.rkt")
(provide b-rem b-print b-let b-input b-repl b-require)
(define (b-rem val) (void))
(define (b-print . vals)
(displayln (string-append* (map ~a vals))))
(define-macro (b-let ID VAL) #'(set! ID VAL))
(define-macro (b-input ID)
#'(b-let ID (let* ([str (read-line)]
[num (string->number (string-trim str))])
(or num str))))
(define-macro (b-repl . ARGS)
(with-pattern ([STMTS (pattern-case-filter #'ARGS
[(b-expr . EXPR-ARGS) #'(b-print (b-expr . EXPR-ARGS))]
[OTHER-STMT #'OTHER-STMT])])
#'(begin . STMTS)))
(define-macro (b-require ID) #'(void))