[array_unique] at tagSwap.net: Open Source Lasso Code

[array_unique]

Description

Link: [array_unique]

Author: Jason Huck

Category: Array

Version: 8.5.x

License: Public Domain

Posted: Jun. 18, 2008

Updated: Jan. 01, 0001

More by this author...

This is a subclassed array which will not add duplicate items. Useful in situations where the order of insertion is important, and thus using a [set] is not an option. Otherwise, works identically to a standard array.

Parameters

none

Sample Usage

var('test') = array_unique('a','b','c');

$test->insert('a'); // will not be inserted
$test->insert('m'=1); // also works with pairs
$test->insert('m'=2); // same key inserts because value is different
$test->insertfirst('m'=2); // true duplicate does not insert
$test->insert('d');

$test->insertfirst('b'); // will not be inserted
$test->insertfirst('z');

$test->insertlast('c'); // will not be inserted
$test->insertlast('e');

var('more') = array('f','g','h','x','y','z');
$test->insertfrom($more->iterator); // will not (re)insert z

$test; // returns a standard array: z,a,b,c,m=1,m=2,d,e,f,g,h,x,y

// iteration, etc. works as expected.
iterate($test, local('i'));
	#i + '<br />\n';
/iterate;

Source Code

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define_type(
	'array_unique', 'array',
	-prototype,
	-description='An array that will only hold unique values.'
);
	define_tag('insert');
		local('v') = @params->first;
		local('p') = (params->size > 1 ? @params->second | self->parent->size + 1);			
		!self->parent->find(#v) ? self->parent->insert(#v, #p);
	/define_tag;
	
	define_tag('insertfirst');
		self->insert(params->first, 1);
	/define_tag;
	
	define_tag('insertfrom');
		local('c') = @params->first;
		
		while(!#c->atend);
			self->insert(#c->value);
			null(#c->forward);
		/while;
	/define_tag;
	
	define_tag('insertlast');
		self->insert(params->first, self->parent->size + 1);
	/define_tag;
	
	define_tag('onconvert');
		return(self->parent);
	/define_tag;
/define_type;

Related Tags

Comments

01/28/2011, BRYCE SMITH
Count elements not added
Great tag. Very useful. Thanks for making it available to us. I am adding a couple hundred unique elements to an array using this tag and was wondering if there was some way to check and see if the element was added each time I loop through. I'd like to make a count of all instances of an element not added, until one is, then start the count over. Is there and undocumented feature for that? Thanks much.