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hebdemnobad

Member

From: northamerica

Registered: 20-Apr-2011

Posts: 1,543

Website

what does the listcat function do?

colleagues:

what does the listcat function do? i wrote a simple app to display the output of a listcat function with the second argument set to 'NIL'...and the output is the same...what does that second argument do?

here is my simple app:

typeof lcatlist = [S r1];;

fun listcat (p, q)=

  if p==nil

  then

    q

  else let p -> [h nxt] in

    h::listcat nxt q;;
    
    
 

fun main ()=
	//_cacheActivate; 
	set lcatlist = "henry"::"martha"::"john"::nil;
	_showconsole;
	_fooSList (listcat lcatlist nil);
	_fooSList  lcatlist;
	0;;

iri you used listcat in getting the list of all files in a partition....what reason is it needed for?

hebdemnobad

Member

From: northamerica

Registered: 20-Apr-2011

Posts: 1,543

Website

Re: what does the listcat function do?

ok, i did another test....

fun main ()=
	//_cacheActivate; 
	set lcatlist = "henry"::"martha"::"john"::nil;
	let "jimmy"::"johnny"::nil -> second_parameter_list in
	(
	_showconsole;
	_fooSList (listcat lcatlist second_parameter_list);
	_fooSList  lcatlist;
	);
	0;;

does the listcat just put two lists together without including the 'nil', (the last element) of the first list?

Last edited by hebdemnobad (16-Dec-2014 19:58:00)

Bob Le Gob

Scol language & Scol applications developer

Registered: 9-Apr-2009

Posts: 26

Re: what does the listcat function do?

yes, this is exactly what it does.

iri

Admin. / Scol language & Scol apps developer

From: France

Registered: 22-Feb-2009

Posts: 2,024

Website

Re: what does the listcat function do?

listcat => lists concatenation

fun main ()=
	//_cacheActivate; 
	set lcatlist = "henry"::"martha"::"john"::nil;
	_showconsole;
	_fooSList (listcat lcatlist nil);
	_fooSList  lcatlist;
	0;;

Of course, if you set the argument to nil ...
You are right, it is also very important to check that the behavior is correct with unexpected values