#lang mzscheme

(require srfi/13/string
         (file "base.ss"))

(provide symbol-append
         symbol-upcase
         symbol-downcase)

;; symbol-append : (U symbol string integer boolean) ... -> symbol
(define (symbol-append . args)
  (string->symbol 
   (string-concatenate 
    (map (lambda (item)
           (cond
             [(symbol? item) (symbol->string item)]
             [(string? item) item]
             [(number? item) (number->string item)]
             [(boolean? item) (if item "true" "false")]
             [else
              (raise-exn exn:fail:unlib
                (format "Expected (list-of (U symbol string number boolean)). Received: ~a" args))]))
         args))))

;; symbol-upcase : symbol -> symbol
(define (symbol-upcase sym)
  (string->symbol (string-upcase (symbol->string sym))))

;; symbol-downcase : symbol -> symbol
(define (symbol-downcase sym)
  (string->symbol (string-downcase (symbol->string sym))))