#lang racket/base
;; Racket's `read`, behind the typed import in sexp.rhm. Not for direct use.
(require racket/port)
(provide read_str read_stdin
         sexp_is_symbol sexp_is_number sexp_is_string sexp_is_list
         sexp_to_symbol sexp_to_number sexp_to_string
         sexp_length sexp_ref sexp_to_text)
(define (read_str str) (with-input-from-string str read))
(define (read_stdin) (read))
(define (sexp_is_symbol x) (symbol? x))
(define (sexp_is_number x) (exact-integer? x))
(define (sexp_is_string x) (string? x))
(define (sexp_is_list x) (list? x))
(define (sexp_to_symbol x) x)
(define (sexp_to_number x) x)
(define (sexp_to_string x) (string->immutable-string x))
;; Shplait lists are not Racket lists, so lists cross by length and index.
(define (sexp_length x) (length x))
(define (sexp_ref x i) (list-ref x i))
(define (sexp_to_text x) (string->immutable-string (format "~s" x)))