System Function DL - Revision history

WikiSysop at 05:14, 16 April 2018

2018-04-16T05:14:53Z

← Older revision		Revision as of 01:14, 16 April 2018
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	{{BoxEnd\|<apll>Z</apll> returned by APL's interpreter - is a scalar number, showing exactly how many actual seconds APL was delayed and <apll>Z</apll>'s value is normally somewhat close to input R's value.}}		{{BoxEnd\|<apll>Z</apll> returned by APL's interpreter - is a scalar number, showing exactly how many actual seconds APL was delayed and <apll>Z</apll>'s value is normally somewhat close to input R's value.}}

	<p>Monadic system function ⎕DL is similar to a sleep or thread sleep routine in other languages.</p>		<p>Monadic system function <apll>⎕DL</apll> is similar to a sleep or thread sleep routine in other languages.</p>

	<p>The following pauses NARS APL program execution for roughly greater than six and a half seconds:</p>		<p>The following pauses NARS APL program execution for roughly greater than six and a half seconds:</p>

WikiSysop at 05:14, 16 April 2018

2018-04-16T05:14:09Z

← Older revision		Revision as of 01:14, 16 April 2018
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	<p>The following pauses NARS APL program execution for roughly greater than six and a half seconds:</p>		<p>The following pauses NARS APL program execution for roughly greater than six and a half seconds:</p>

	<~~apll~~>~~      ~~ ⎕DL 6.651 ~~<br>~~		<pre>
	6.646~~<br>~~		⎕DL 6.651
	</~~apll~~>		6.646
			</pre>

	R was 6.651 (user specified). Z returned was 6.646. This system function is useful where concurrent/simultaneous processes are running or APL may be dependent on an external routine/program which is running and that external routine needs to finish <u>first</u>, so for example APL can read in the external results. If <apll>⎕DL</apll> is used in a user function, say within a loop, every R seconds your APL function can check for that external result, e.g. existence of a file, value within that file, etc.<br>		R was 6.651 (user specified). Z returned was 6.646. This system function is useful where concurrent/simultaneous processes are running or APL may be dependent on an external routine/program which is running and that external routine needs to finish <u>first</u>, so for example APL can read in the external results. If <apll>⎕DL</apll> is used in a user function, say within a loop, every R seconds your APL function can check for that external result, e.g. existence of a file, value within that file, etc.<br>

	{{System Variables}}		{{System Variables}}

Robert Wallick: Created Quad DL - Delay Execution NARS wiki page

2015-07-15T03:54:00Z

Created Quad DL - Delay Execution NARS wiki page

New page

⎕DL or system function Quad DL is available in monadic form only.
==Monadic Function==
{{BoxStart|<apll>Z←⎕DL R</apll>
|'''Delays''' APL program execution / pauses APL processing for the number of seconds specified in R. <apll>R</apll> should be a real number (representing seconds and it is not necessary for <apll>R</apll> to be a whole integer) and <apll>R</apll> should be greater than zero.}}
{{BoxLine|<apll>R</apll> is - normally a number greater than zero.}}
{{BoxEnd|<apll>Z</apll> returned by APL's interpreter - is a scalar number, showing exactly how many actual seconds APL was delayed and <apll>Z</apll>'s value is normally somewhat close to input R's value.}}

Monadic system function ⎕DL is similar to a sleep or thread sleep routine in other languages.

The following pauses NARS APL program execution for roughly greater than six and a half seconds:

<apll>       ⎕DL 6.651 
6.646 
</apll>
R was 6.651 (user specified). Z returned was 6.646. This system function is useful where concurrent/simultaneous processes are running or APL may be dependent on an external routine/program which is running and that external routine needs to finish first, so for example APL can read in the external results. If <apll>⎕DL</apll> is used in a user function, say within a loop, every R seconds your APL function can check for that external result, e.g. existence of a file, value within that file, etc. 

{{System Variables}}