standard-char-p character ⇒  generalized-boolean
| character | a character. | 
| generalized-boolean | a generalized boolean. | 
Returns true if character is of type standard-char; otherwise, returns false.
 (standard-char-p #\Space) ⇒  true
 (standard-char-p #\~) ⇒  true
 ;; This next example presupposes an implementation
 ;; in which #\Bell is a defined character.
 (standard-char-p #\Bell) ⇒  false
Should signal an error of type type-error if character is not a character.