#NEWLINE# @ expose ( 'read-byte' , [ default ( values . W_InputPort , None ) ] , simple = False ) #NEWLINE# def read_byte( w_port , env , cont ) : #NEWLINE# #INDENT# try : #NEWLINE# #INDENT# return do_read_one ( w_port , True , False , env , w_port ) #NEWLINE# #UNINDENT# except UnicodeDecodeError : #NEWLINE# #INDENT# raise SchemeException ( 'read-byte: string is not a well-formed UTF-8 encoding' )