• with-open-stream (var stream) declaration* form* → result*

• var - a variable name.
• stream - a form; evaluated to produce a stream.
• declaration - a declare expression; not evaluated.
• forms - an implicit progn.
• results - the values returned by the forms.

with-open-stream performs a series of operations on stream, returns a value, and then closes the stream.

var is bound to the value of stream, and then forms are executed as an implicit progn. stream is automatically closed on exit from with-open-stream, no matter whether the exit is normal or abnormal.

The stream has dynamic extent; its extent ends when the form is exited.

The consequences are undefined if an attempt is made to assign the the variable var with the forms.

(with-open-stream (s (make-string-input-stream "1 2 3 4")) 
  (+ (read s) 
     (read s) 
     (read s))) 

→

6 

The stream is closed (upon exit).

None.

None.

• Function CLOSE

None.

\issue{DECLS-AND-DOC} \issue{WITH-OPEN-FILE-STREAM-EXTENT:DYNAMIC-EXTENT} \issue{WITH-OPEN-FILE-SETQ:EXPLICITLY-VAGUE}