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cl:functions:finish-output [2019/06/15 02:00]
cl:functions:finish-output [2019/06/16 07:00] (current)
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 +====== Function FINISH-OUTPUT,​ FORCE-OUTPUT,​ CLEAR-OUTPUT ======
 +
 +====Syntax====
 +  * **finish-output** ''&​optional''​ //​output-stream//​ → **[[CL:​Constant Variables:​nil]]** ​
 +  * **force-output** ''&​optional''​ //​output-stream//​ → **[[CL:​Constant Variables:​nil]]** ​
 +  * **clear-output** ''&​optional''​ //​output-stream//​ → **[[CL:​Constant Variables:​nil]]**
 +
 +====Arguments and Values====
 +  * //​output-stream//​ - an //​[[CL:​Glossary:​output]]//​ //​[[CL:​Glossary:​stream designator]]//​. The default is //​[[CL:​Glossary:​standard output]]//.
 +
 +====Description====
 +**finish-output**,​ **force-output**,​ and **clear-output** exercise control over the internal handling of buffered stream output.
 +
 +**finish-output** attempts to ensure that any buffered output sent to //​output-stream//​ has reached its destination,​ and then returns.
 +
 +**force-output** initiates the emptying of any internal buffers but does not wait for completion or acknowledgment to return.
 +
 +**clear-output** attempts to abort any outstanding output operation in progress in order to allow as little output as possible to continue to the destination.
 +
 +If any of these operations does not make sense for //​output-stream//,​ then it does nothing.
 +
 +The precise actions of these //​[[CL:​Glossary:​function|functions]]//​ are //​[[CL:​Glossary:​implementation-dependent]]//​.
 +
 +====Examples====
 +Implementation A:
 +
 +<​blockquote> ​
 +([[CL:​Special Operators:​progn]] ([[CL:​Functions:​princ]] "am i seen?"​) ​
 +       ​(clear-output)) ​
 +<​r>​[[CL:​Constant Variables:​NIL]] </r>
 +</​blockquote>​
 +
 +Implementation B:
 +
 +<​blockquote> ​
 +([[CL:​Special Operators:​progn]] ([[CL:​Functions:​princ]] "am i seen?"​) ​
 +       ​(clear-output))
 +<o>am i seen?</​o>​
 +<​r>​[[CL:​Constant Variables:​NIL]] </r>
 +</​blockquote>​
 +
 +====Side Effects====
 +None.
 +
 +====Affected By====
 +**[[CL:​Variables:​star-standard-output-star|*standard-output*]]**
 +
 +====Exceptional Situations====
 +Should signal an error of type type-error if //​output-stream//​ is not a //​[[CL:​Glossary:​stream designator]]//​.
 +
 +====See Also====
 +  * **[[CL:​Functions:​clear-input|Function CLEAR-INPUT]]**
 +
 +====Notes====
 +None.
 +