;;;; coerce-test.scm

(use test)
(use coerce)

(test-group "Coerce"

  (define unspecified-coerce
    (case-coerce
      ((char)     #\nul)
      ((number)   +nan)
      ((string)   "")
      ((symbol)   '||)
      ((list)     (list))
      ((vector)   (vector))
      (else       (void) ) ) )

  (define (unspecified? obj) (eq? (void) obj))

  (test "lvs"
    '((#\s #\t #\r #\i #\n #\g)
      #(#\s #\t #\r #\i #\n #\g)
      "string"
      "23.45")
    (coerce-all '("string"
                  (#\s #\t #\r #\i #\n #\g)
                  #(#\s #\t #\r #\i #\n #\g)
                  23.45)
                '(list vector string string)))

  ; while unspecified is builtin there is no conversion
  (test-assert "extn"
    (coerce-extend! 'unspecified unspecified? unspecified-coerce))

  (test "ut" 'unspecified (type-of (void)))
  (test "ns" "" (coerce (void) 'string))
  
  (test-assert "string extension"
    (coerce-extend! 'string string?
      (case-coerce
        ((unspecified) (if (string=? "" object) (void) (on-error))))))

  (test-error "su1" (coerce "abc" 'unspecified))
  (test "su2" (void) (coerce "" 'unspecified))

  (let-values (((pred proc) (coerce-extension 'string))) 
    (test-assert "override string extension"
      (coerce-extend! 'string string?
        (case-coerce
          ((input-port)  `(open-input-file ,object))
          ((output-port) `(open-output-file ,object))
          (else (proc object 'string on-error))))) )

  (test "sp" '(open-output-file "foo") (coerce "foo" 'output-port))
)