LevenshteinDistanceSearch.m

#import <Foundation/Foundation.h>

#import "JXTrie.h"

#define DICTIONARY	@"/usr/share/dict/words"
#define TARGET	@"goober"
#define MAX_COST	1

// Apparently, recreating the trie from the raw word list is faster than archiving/unarchiving using NSKeyedArchiver.

int main (int argc, const char * argv[]) {
	
	@autoreleasepool {
		
		NSString *target;
		NSUInteger maxCost;
		NSString *dictionary;
		
		NSTimeInterval start;
		NSTimeInterval duration;
		
		if ([NSProcessInfo processInfo].arguments.count < 3) {
			fprintf(stderr, "usage: %s [<search string> <maximum distance>] [<dictionary path>]\n",
					[NSProcessInfo processInfo].processName.UTF8String);
			target = TARGET;
			maxCost = MAX_COST;
		}
		else {
			target = [NSProcessInfo processInfo].arguments[1];
			maxCost = [NSProcessInfo processInfo].arguments[2].integerValue;
		}
		
		if ([NSProcessInfo processInfo].arguments.count > 3) {
			dictionary = [NSProcessInfo processInfo].arguments[3];
		}
		else {
			dictionary = DICTIONARY;
		}
		
		// Read dictionary file into a trie
		JXTrie *trie;
		
		start = [NSDate timeIntervalSinceReferenceDate];
		
		NSString *wordListText = [NSString stringWithContentsOfFile:dictionary encoding:NSUTF8StringEncoding error:NULL];
		
		trie = [JXTrie trieWithWordListString:wordListText];
		
		duration = [NSDate timeIntervalSinceReferenceDate] - start;
		
		//NSLog(@"\n\n%@", trie);
		NSLog(@"Read %lu words into %lu nodes. ", (unsigned long)trie.count, (unsigned long)trie.nodeCount);
		NSLog(@"Creating the trie for \"%@\" took %.4f s. ", dictionary, (double)duration);
		
		
		NSArray *results = nil;
		
		start = [NSDate timeIntervalSinceReferenceDate];
		results = [trie search:target maximumDistance:maxCost sortingResults:YES];
		duration = [NSDate timeIntervalSinceReferenceDate] - start;
		
		NSLog(@"\n%@", results);
		
		NSLog(@"Search for \"%@\" took %.4f s. ", target, (double)duration);
		
	}
	
	return 0;
}