port-open
-- r7rs
Type port
;input-port-eof
;binary-input-port-open
;binary-input-port-eof
;binary-output-port-open
;textual-input-port-open
;textual-input-port-eof
;textual-output-port-open
;(lambda (value) (and (port? value) (or (input-port-open? value) (output-port-open? value))))