typespec—a type specifier.
stream-element-type returns a type specifier that
indicates the types of objects that may be read from
or written to stream.
Streams created by
open have an element type
integer or a subtype of type
;; Note that the stream must accomodate at least the specified type, ;; but might accomodate other types. Further note that even if it does ;; accomodate exactly the specified type, the type might be specified in ;; any of several ways. (with-open-file (s "test" :element-type '(integer 0 1) :if-exists :error :direction :output) (stream-element-type s)) → INTEGER or→ (UNSIGNED-BYTE 16) or→ (UNSIGNED-BYTE 8) or→ BIT or→ (UNSIGNED-BYTE 1) or→ (INTEGER 0 1) or→ (INTEGER 0 (2))
Should signal an error of type
type-error if stream is not a stream.