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<channel>
	<title>MRo Blog &#187; Search</title>
	<atom:link href="http://blog.mro.name/tag/search/feed/" rel="self" type="application/rss+xml" />
	<link>http://blog.mro.name</link>
	<description>Marcus Rohrmoser mobile Software</description>
	<lastBuildDate>Wed, 23 Jun 2010 11:32:27 +0000</lastBuildDate>
	<language>en</language>
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		<item>
		<title>Binary Search NSArray</title>
		<link>http://blog.mro.name/2010/01/binary-search-nsarray/</link>
		<comments>http://blog.mro.name/2010/01/binary-search-nsarray/#comments</comments>
		<pubDate>Tue, 12 Jan 2010 22:02:07 +0000</pubDate>
		<dc:creator>mro</dc:creator>
				<category><![CDATA[Articles in english]]></category>
		<category><![CDATA[development]]></category>
		<category><![CDATA[Binary]]></category>
		<category><![CDATA[Cocoa]]></category>
		<category><![CDATA[gist]]></category>
		<category><![CDATA[git]]></category>
		<category><![CDATA[github]]></category>
		<category><![CDATA[iPhone]]></category>
		<category><![CDATA[NSArray]]></category>
		<category><![CDATA[Objective C]]></category>
		<category><![CDATA[OS X]]></category>
		<category><![CDATA[Search]]></category>

		<guid isPermaLink="false">http://blog.mro.name/?p=1652</guid>
		<description><![CDATA[Though CFArray comes with binary search capability, NSArray does not &#8211; at least not within the iPhone SDK. The indexOfObject:inSortedRange:options:usingComparator: can&#8217;t be found. Plus the CFArrayBSearchValues doesn&#8217;t tell you whether the key actually is part of the list or not. That&#8217;s what the Java JDK does, so let&#8217;s implement some category methods -&#40;NSInteger&#41;binarySearch:&#40;id&#41;key; -&#40;NSInteger&#41;binarySearch:&#40;id&#41;key usingSelector:&#40;SEL&#41;comparator; [...]]]></description>
			<content:encoded><![CDATA[<p>Though <a href="http://developer.apple.com/mac/library/DOCUMENTATION/CoreFoundation/Reference/CFArrayRef/index.html">CFArray</a> comes with <a href="http://en.wikipedia.org/wiki/Binary_search_algorithm#Iterative">binary search</a> capability, <a href="http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSArray_Class/NSArray.html">NSArray</a> does not &#8211; at least not within the iPhone SDK. The <a href="http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSArray_Class/NSArray.html#//apple_ref/occ/instm/NSArray/indexOfObject:inSortedRange:options:usingComparator:">indexOfObject:inSortedRange:options:usingComparator:</a> can&#8217;t be found.</p>
<p>Plus the <a href="http://developer.apple.com/mac/library/DOCUMENTATION/CoreFoundation/Reference/CFArrayRef/Reference/reference.html#//apple_ref/doc/uid/20001192-CH201-F10956">CFArrayBSearchValues</a> doesn&#8217;t tell you whether the key actually is part of the list or not. That&#8217;s what the <a href="http://java.sun.com/j2se/1.5.0/docs/api/java/util/Arrays.html#binarySearch(T[],%20T,%20java.util.Comparator)">Java JDK</a> does, so let&#8217;s implement some <a href="http://developer.apple.com/mac/library/documentation/General/Conceptual/DevPedia-CocoaCore/Category.html">category</a> methods</p>

<div class="wp_syntax"><div class="code"><pre class="objc" style="font-family:monospace;"><span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingSelector<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">SEL</span><span style="color: #002200;">&#41;</span>comparator;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingSelector<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">SEL</span><span style="color: #002200;">&#41;</span>comparator inRange<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">NSRange</span><span style="color: #002200;">&#41;</span>range;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingFunction<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span>NSInteger <span style="color: #002200;">&#40;</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span>, <span style="color: #a61390;">id</span>, <span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#41;</span>comparator context<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>context;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingFunction<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span>NSInteger <span style="color: #002200;">&#40;</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span>, <span style="color: #a61390;">id</span>, <span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#41;</span>comparator context<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>context inRange<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">NSRange</span><span style="color: #002200;">&#41;</span>range;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingDescriptors<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSArray</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>sortDescriptors;
<span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingDescriptors<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSArray</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>sortDescriptors inRange<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">NSRange</span><span style="color: #002200;">&#41;</span>range;</pre></div></div>

<p>ourselves, like</p>

<div class="wp_syntax"><div class="code"><pre class="objc" style="font-family:monospace;"><span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>NSInteger<span style="color: #002200;">&#41;</span>binarySearch<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span><span style="color: #002200;">&#41;</span>key usingFunction<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span>NSInteger <span style="color: #002200;">&#40;</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">id</span>, <span style="color: #a61390;">id</span>, <span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span><span style="color: #002200;">&#41;</span>comparator context<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">void</span> <span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>context inRange<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">NSRange</span><span style="color: #002200;">&#41;</span>range
<span style="color: #002200;">&#123;</span>
    NSLogD<span style="color: #002200;">&#40;</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;[NSArray(MroBinarySearch) binarySearch:%@ usingFunction:]&quot;</span>, key<span style="color: #002200;">&#41;</span>;
    <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>self.count <span style="color: #002200;">==</span> <span style="color: #2400d9;">0</span> || key <span style="color: #002200;">==</span> <span style="color: #a61390;">nil</span> || comparator <span style="color: #002200;">==</span> <span style="color: #a61390;">NULL</span><span style="color: #002200;">&#41;</span>
        <span style="color: #a61390;">return</span> <span style="color: #002200;">&#91;</span>self binarySearch<span style="color: #002200;">:</span>key usingSelector<span style="color: #002200;">:</span><span style="color: #a61390;">nil</span> inRange<span style="color: #002200;">:</span>range<span style="color: #002200;">&#93;</span>;
&nbsp;
<span style="color: #11740a; font-style: italic;">//	check overflow?</span>
    NSInteger min <span style="color: #002200;">=</span> range.location;
    NSInteger max <span style="color: #002200;">=</span> range.location <span style="color: #002200;">+</span> range.length <span style="color: #002200;">-</span> <span style="color: #2400d9;">1</span>;
&nbsp;
    <span style="color: #a61390;">while</span> <span style="color: #002200;">&#40;</span>min <span style="color: #002200;">&amp;</span>lt; <span style="color: #002200;">=</span> max<span style="color: #002200;">&#41;</span>
    <span style="color: #002200;">&#123;</span>
        <span style="color: #11740a; font-style: italic;">// http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html</span>
        <span style="color: #a61390;">const</span> NSInteger mid <span style="color: #002200;">=</span> min <span style="color: #002200;">+</span> <span style="color: #002200;">&#40;</span>max <span style="color: #002200;">-</span> min<span style="color: #002200;">&#41;</span> <span style="color: #002200;">/</span> <span style="color: #2400d9;">2</span>;
        <span style="color: #a61390;">switch</span> <span style="color: #002200;">&#40;</span>comparator<span style="color: #002200;">&#40;</span>key, <span style="color: #002200;">&#91;</span>self objectAtIndex<span style="color: #002200;">:</span>mid<span style="color: #002200;">&#93;</span>, context<span style="color: #002200;">&#41;</span><span style="color: #002200;">&#41;</span>
        <span style="color: #002200;">&#123;</span>
            <span style="color: #a61390;">case</span> NSOrderedSame<span style="color: #002200;">:</span>
                <span style="color: #a61390;">return</span> mid;
            <span style="color: #a61390;">case</span> NSOrderedDescending<span style="color: #002200;">:</span>
                min <span style="color: #002200;">=</span> mid <span style="color: #002200;">+</span> <span style="color: #2400d9;">1</span>;
                <span style="color: #a61390;">break</span>;
            <span style="color: #a61390;">case</span> NSOrderedAscending<span style="color: #002200;">:</span>
                max <span style="color: #002200;">=</span> mid <span style="color: #002200;">-</span> <span style="color: #2400d9;">1</span>;
                <span style="color: #a61390;">break</span>;
        <span style="color: #002200;">&#125;</span>
    <span style="color: #002200;">&#125;</span>
    <span style="color: #a61390;">return</span> <span style="color: #002200;">-</span><span style="color: #002200;">&#40;</span>min <span style="color: #002200;">+</span> <span style="color: #2400d9;">1</span><span style="color: #002200;">&#41;</span>;
<span style="color: #002200;">&#125;</span></pre></div></div>

<p>See the <a href="http://gist.github.com/275631/">full interface + implementation + testcase without html encoding dirt at github</a>.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.mro.name/2010/01/binary-search-nsarray/feed/</wfw:commentRss>
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		</item>
		<item>
		<title>CocoaTouch, CoreData and binary String Search</title>
		<link>http://blog.mro.name/2009/10/cocoatouch-coredata-and-binary-string-search/</link>
		<comments>http://blog.mro.name/2009/10/cocoatouch-coredata-and-binary-string-search/#comments</comments>
		<pubDate>Fri, 23 Oct 2009 18:27:59 +0000</pubDate>
		<dc:creator>mro</dc:creator>
				<category><![CDATA[Articles in english]]></category>
		<category><![CDATA[development]]></category>
		<category><![CDATA[Binary]]></category>
		<category><![CDATA[Cocoa]]></category>
		<category><![CDATA[CoreData]]></category>
		<category><![CDATA[iPhone]]></category>
		<category><![CDATA[NSPredicate]]></category>
		<category><![CDATA[Objective C]]></category>
		<category><![CDATA[Search]]></category>

		<guid isPermaLink="false">http://blog.mro.name/?p=1321</guid>
		<description><![CDATA[The query optimiser for NSPredicate queries ontop CoreData/SQLite on the iPhone is a bit rudimentary (cough) and so I had to optimise myself to get binary-search enabled quick results: +&#40;NSPredicate*&#41;findBySearchTerm:&#40;NSString*&#41;rawTerm within:&#40;BOOL&#41;within context:&#40;NSManagedObjectContext*&#41;context &#123; NSSet *tokens = &#91;MovieM indexTokens:rawTerm&#93;; if&#40;tokens == nil &#124;&#124; tokens.count &#38;lt; = 0&#41; return &#91;NSPredicate predicateWithFormat:@&#34;FALSEPREDICATE&#34;&#93;; NSMutableArray *preds = &#91;NSMutableArray arrayWithCapacity:tokens.count&#93;; &#160; [...]]]></description>
			<content:encoded><![CDATA[<p>The <a href="http://en.wikipedia.org/wiki/Query_optimizer">query optimiser</a> for <a href="http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSPredicate_Class/Reference/NSPredicate.html">NSPredicate</a> queries ontop CoreData/SQLite on the iPhone is a bit rudimentary (cough) and so I had to optimise myself to get binary-search enabled quick results:</p>
<p><span id="more-1321"></span></p>

<div class="wp_syntax"><div class="code"><pre class="objc" style="font-family:monospace;"><span style="color: #002200;">+</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSPredicate</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>findBySearchTerm<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSString</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>rawTerm within<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #a61390;">BOOL</span><span style="color: #002200;">&#41;</span>within context<span style="color: #002200;">:</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSManagedObjectContext</span><span style="color: #002200;">*</span><span style="color: #002200;">&#41;</span>context
<span style="color: #002200;">&#123;</span>
    <span style="color: #400080;">NSSet</span> <span style="color: #002200;">*</span>tokens <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span>MovieM indexTokens<span style="color: #002200;">:</span>rawTerm<span style="color: #002200;">&#93;</span>;
    <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>tokens <span style="color: #002200;">==</span> <span style="color: #a61390;">nil</span> || tokens.count <span style="color: #002200;">&amp;</span>lt; <span style="color: #002200;">=</span> <span style="color: #2400d9;">0</span><span style="color: #002200;">&#41;</span>
        <span style="color: #a61390;">return</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSPredicate</span> predicateWithFormat<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;FALSEPREDICATE&quot;</span><span style="color: #002200;">&#93;</span>;
    <span style="color: #400080;">NSMutableArray</span> <span style="color: #002200;">*</span>preds <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSMutableArray</span> arrayWithCapacity<span style="color: #002200;">:</span>tokens.count<span style="color: #002200;">&#93;</span>;
&nbsp;
    <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>within <span style="color: #002200;">==</span> <span style="color: #a61390;">NO</span> <span style="color: #002200;">&amp;</span>amp;<span style="color: #002200;">&amp;</span>amp; context <span style="color: #002200;">!=</span> <span style="color: #a61390;">nil</span><span style="color: #002200;">&#41;</span>
    <span style="color: #002200;">&#123;</span>
	<span style="color: #11740a; font-style: italic;">// As queries aren't optimised by default we do it ourselves:</span>
	<span style="color: #11740a; font-style: italic;">// 1st: find matching entries from the IndexKey table - leveraging it's index:</span>
        <span style="color: #400080;">NSFetchRequest</span> <span style="color: #002200;">*</span>fr <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #002200;">&#91;</span><span style="color: #400080;">NSFetchRequest</span> alloc<span style="color: #002200;">&#93;</span> init<span style="color: #002200;">&#93;</span>;
        fr.entity <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSEntityDescription</span> entityForName<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;IndexKey&quot;</span> inManagedObjectContext<span style="color: #002200;">:</span>context<span style="color: #002200;">&#93;</span>;
        <span style="color: #400080;">NSMutableSet</span> <span style="color: #002200;">*</span>result <span style="color: #002200;">=</span> <span style="color: #a61390;">nil</span>;
        <span style="color: #400080;">NSError</span> <span style="color: #002200;">*</span>error <span style="color: #002200;">=</span> <span style="color: #a61390;">nil</span>;
        <span style="color: #a61390;">for</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSString</span> <span style="color: #002200;">*</span>token <span style="color: #a61390;">in</span> tokens<span style="color: #002200;">&#41;</span>
        <span style="color: #002200;">&#123;</span>
	    <span style="color: #11740a; font-style: italic;">// BETWEEN uses the table-index while BEGINSWITH does not:</span>
            fr.predicate <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSPredicate</span> predicateWithFormat<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;key BETWEEN {%@, %@}&quot;</span>, token, <span style="color: #002200;">&#91;</span>MovieM upperBoundSearchString<span style="color: #002200;">:</span>token<span style="color: #002200;">&#93;</span><span style="color: #002200;">&#93;</span>;
            <span style="color: #400080;">NSArray</span> <span style="color: #002200;">*</span>keys <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span>context executeFetchRequest<span style="color: #002200;">:</span>fr error<span style="color: #002200;">:&amp;</span>amp;error<span style="color: #002200;">&#93;</span>;
            <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>error <span style="color: #002200;">!=</span> <span style="color: #a61390;">nil</span><span style="color: #002200;">&#41;</span>
                NSLog<span style="color: #002200;">&#40;</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;Oops: %@&quot;</span>, error<span style="color: #002200;">&#41;</span>;
	    <span style="color: #11740a; font-style: italic;">// turn IndexKey entries to movies (join up):</span>
            <span style="color: #400080;">NSArray</span> <span style="color: #002200;">*</span>movs <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span>keys valueForKey<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;movie&quot;</span><span style="color: #002200;">&#93;</span>;
	    <span style="color: #11740a; font-style: italic;">// aggregate the results for each token:</span>
            <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>result <span style="color: #002200;">==</span> <span style="color: #a61390;">nil</span><span style="color: #002200;">&#41;</span>
                result <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSMutableSet</span> setWithArray<span style="color: #002200;">:</span>movs<span style="color: #002200;">&#93;</span>;
            <span style="color: #a61390;">else</span>
                <span style="color: #002200;">&#91;</span>result intersectSet<span style="color: #002200;">:</span><span style="color: #002200;">&#91;</span><span style="color: #400080;">NSSet</span> setWithArray<span style="color: #002200;">:</span>movs<span style="color: #002200;">&#93;</span><span style="color: #002200;">&#93;</span>;
        <span style="color: #002200;">&#125;</span>
        <span style="color: #002200;">&#91;</span>fr release<span style="color: #002200;">&#93;</span>;
        <span style="color: #a61390;">return</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSPredicate</span> predicateWithFormat<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;SELF IN %@&quot;</span>, result<span style="color: #002200;">&#93;</span>;
    <span style="color: #002200;">&#125;</span>
&nbsp;
    <span style="color: #400080;">NSPredicate</span> <span style="color: #002200;">*</span>template <span style="color: #002200;">=</span> <span style="color: #a61390;">nil</span>;
    <span style="color: #a61390;">if</span><span style="color: #002200;">&#40;</span>within<span style="color: #002200;">&#41;</span>
        template <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSPredicate</span> predicateWithFormat<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;ANY index.key CONTAiNS $searchTerm&quot;</span><span style="color: #002200;">&#93;</span>;
    <span style="color: #a61390;">else</span>
        template <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSPredicate</span> predicateWithFormat<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;ANY index.key BEGINSWITH $searchTerm&quot;</span><span style="color: #002200;">&#93;</span>;
    <span style="color: #a61390;">for</span><span style="color: #002200;">&#40;</span><span style="color: #400080;">NSString</span> <span style="color: #002200;">*</span>token <span style="color: #a61390;">in</span> tokens<span style="color: #002200;">&#41;</span>
    <span style="color: #002200;">&#123;</span>
        <span style="color: #400080;">NSDictionary</span> <span style="color: #002200;">*</span>params <span style="color: #002200;">=</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSDictionary</span> dictionaryWithObject<span style="color: #002200;">:</span>token forKey<span style="color: #002200;">:</span><span style="color: #bf1d1a;">@</span><span style="color: #bf1d1a;">&quot;searchTerm&quot;</span><span style="color: #002200;">&#93;</span>;
        <span style="color: #002200;">&#91;</span>preds addObject<span style="color: #002200;">:</span><span style="color: #002200;">&#91;</span>template predicateWithSubstitutionVariables<span style="color: #002200;">:</span>params<span style="color: #002200;">&#93;</span><span style="color: #002200;">&#93;</span>;
    <span style="color: #002200;">&#125;</span>
    <span style="color: #a61390;">return</span> <span style="color: #002200;">&#91;</span><span style="color: #400080;">NSCompoundPredicate</span> andPredicateWithSubpredicates<span style="color: #002200;">:</span>preds<span style="color: #002200;">&#93;</span>;
<span style="color: #002200;">&#125;</span></pre></div></div>

<p>Helpers herein are</p>
<ul>
<li><code>[MovieM indexTokens:rawTerm]</code> folds diacritics and uppercase and cuts at whitespace or interpunction,</li>
<li><code>[MovieM upperBoundSearchString:token]</code> which was inspired by <a href="http://developer.apple.com/mac/library/samplecode/DerivedProperty/listing8.html">Apple Sample Code &#8220;DerivedProperty&#8221;</a>.</li>
</ul>
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