WIP: Use FZF backend instead

NSString+Score.h

@@ -0,0 +1,30 @@
+//
+//  NSString+Score.h
+//
+//  Created by Nicholas Bruning on 5/12/11.
+//  Copyright (c) 2011 Involved Pty Ltd. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+enum{
+    NSStringScoreOptionNone                         = 1 << 0,
+    NSStringScoreOptionFavorSmallerWords            = 1 << 1,
+    NSStringScoreOptionReducedLongStringPenalty     = 1 << 2
+};
+
+typedef NSUInteger NSStringScoreOption;
+
+@interface NSString (Score)
+
+- (CGFloat) scoreAgainst:(NSString *)otherString;
+- (CGFloat) scoreAgainst:(NSString *)otherString fuzziness:(NSNumber *)fuzziness;
+- (CGFloat) scoreAgainst:(NSString *)otherString fuzziness:(NSNumber *)fuzziness options:(NSStringScoreOption)options;
+
+- (CGFloat) scoreAgainst:(NSString *)anotherString fuzziness:(NSNumber *)fuzziness options:(NSStringScoreOption)options
+     invalidCharacterSet:(NSCharacterSet *)invalidCharacterSet decomposedString:(NSString *)string;
+
+- (NSString *)decomposedStringWithInvalidCharacterSet:(NSCharacterSet *)invalidCharacterSet;
+- (NSCharacterSet *)invalidCharacterSet;
+
+@end

NSString+Score.m

@@ -0,0 +1,164 @@
+//
+//  NSString+Score.m
+//
+//  Created by Nicholas Bruning on 5/12/11.
+//  Copyright (c) 2011 Involved Pty Ltd. All rights reserved.
+//
+
+//score reference: http://jsfiddle.net/JrLVD/
+
+#import "NSString+Score.h"
+
+@implementation NSString (Score)
+
+- (CGFloat) scoreAgainst:(NSString *)otherString{
+    return [self scoreAgainst:otherString fuzziness:nil];
+}
+
+- (CGFloat) scoreAgainst:(NSString *)otherString fuzziness:(NSNumber *)fuzziness{
+    return [self scoreAgainst:otherString fuzziness:fuzziness options:NSStringScoreOptionNone];
+}
+
+- (CGFloat) scoreAgainst:(NSString *)anotherString fuzziness:(NSNumber *)fuzziness options:(NSStringScoreOption)options {
+    NSCharacterSet *invalidCharacterSet = [self invalidCharacterSet];
+    NSString *string = [self decomposedStringWithInvalidCharacterSet:invalidCharacterSet];
+    return [self scoreAgainst:anotherString fuzziness:fuzziness options:options invalidCharacterSet:invalidCharacterSet decomposedString:string];
+}
+
+- (NSCharacterSet *)invalidCharacterSet {
+    NSMutableCharacterSet *workingInvalidCharacterSet = [NSMutableCharacterSet lowercaseLetterCharacterSet];
+    [workingInvalidCharacterSet formUnionWithCharacterSet:[NSCharacterSet uppercaseLetterCharacterSet]];
+    [workingInvalidCharacterSet addCharactersInString:@" "];
+    NSCharacterSet *invalidCharacterSet = [workingInvalidCharacterSet invertedSet];
+    return invalidCharacterSet;
+}
+
+- (NSString *)decomposedStringWithInvalidCharacterSet:(NSCharacterSet *)invalidCharacterSet {
+    NSString *string = [[[self decomposedStringWithCanonicalMapping] componentsSeparatedByCharactersInSet:invalidCharacterSet] componentsJoinedByString:@""];
+    return string;
+}
+
+- (CGFloat) scoreAgainst:(NSString *)anotherString fuzziness:(NSNumber *)fuzziness options:(NSStringScoreOption)options
+     invalidCharacterSet:(NSCharacterSet *)invalidCharacterSet decomposedString:(NSString *)string {
+    NSString *otherString = [[[anotherString decomposedStringWithCanonicalMapping] componentsSeparatedByCharactersInSet:invalidCharacterSet] componentsJoinedByString:@""];
+
+    // If the string is equal to the abbreviation, perfect match.
+    if([string isEqualToString:otherString]) return (CGFloat) 1.0f;
+
+    //if it's not a perfect match and is empty return 0
+    if([otherString length] == 0) return (CGFloat) 0.0f;
+
+    CGFloat totalCharacterScore = 0;
+    NSUInteger otherStringLength = [otherString length];
+    NSUInteger stringLength = [string length];
+    BOOL startOfStringBonus = NO;
+    CGFloat otherStringScore;
+    CGFloat fuzzies = 1;
+    CGFloat finalScore;
+
+    NSString *otherUpper = [otherString uppercaseString];
+    NSString *otherLower = [otherString lowercaseString];
+
+    CGFloat fuzzinessFloat = fuzziness.floatValue;
+
+    unichar space = [@" " characterAtIndex:0];
+
+    // Walk through abbreviation and add up scores.
+    for(uint index = 0; index < otherStringLength; index++){
+        CGFloat characterScore = 0.1;
+        NSInteger indexInString = NSNotFound;
+        NSRange rangeChrLowercase;
+        NSRange rangeChrUppercase;
+
+        NSRange r  =NSMakeRange(index, 1);
+
+        unichar chr = [otherString characterAtIndex:index];
+
+        NSString *upperChr = [otherUpper substringWithRange:r];
+        NSString *lowerChr = [otherLower substringWithRange:r];
+
+        //make these next few lines leverage NSNotfound, methinks.
+        rangeChrLowercase = [string rangeOfString:lowerChr];
+        rangeChrUppercase = [string rangeOfString:upperChr];
+
+        if(rangeChrLowercase.location == NSNotFound && rangeChrUppercase.location == NSNotFound){
+            if(fuzziness){
+                fuzzies += 1 - fuzzinessFloat;
+            } else {
+                return 0; // this is an error!
+            }
+
+        } else if (rangeChrLowercase.location != NSNotFound && rangeChrUppercase.location != NSNotFound){
+            indexInString = MIN(rangeChrLowercase.location, rangeChrUppercase.location);
+
+        } else if(rangeChrLowercase.location != NSNotFound || rangeChrUppercase.location != NSNotFound){
+            indexInString = rangeChrLowercase.location != NSNotFound ? rangeChrLowercase.location : rangeChrUppercase.location;
+
+        } else {
+            indexInString = MIN(rangeChrLowercase.location, rangeChrUppercase.location);
+
+        }
+
+        // Set base score for matching chr
+
+        // Same case bonus.
+        if(indexInString != NSNotFound && [string characterAtIndex:indexInString] == chr){
+            characterScore += 0.1;
+        }
+
+        // Consecutive letter & start-of-string bonus
+        if(indexInString == 0){
+            // Increase the score when matching first character of the remainder of the string
+            characterScore += 0.6;
+            if(index == 0){
+                // If match is the first character of the string
+                // & the first character of abbreviation, add a
+                // start-of-string match bonus.
+                startOfStringBonus = YES;
+            }
+        } else if(indexInString != NSNotFound) {
+            // Acronym Bonus
+            // Weighing Logic: Typing the first character of an acronym is as if you
+            // preceded it with two perfect character matches.
+
+            if([string characterAtIndex:indexInString - 1] == space) {
+                characterScore += 0.8;
+            }
+        }
+
+        // Left trim the already matched part of the string
+        // (forces sequential matching).
+        if(indexInString != NSNotFound){
+            string = [string substringFromIndex:indexInString + 1];
+        }
+
+        totalCharacterScore += characterScore;
+    }
+
+    if(NSStringScoreOptionFavorSmallerWords == (options & NSStringScoreOptionFavorSmallerWords)){
+        // Weigh smaller words higher
+        return totalCharacterScore / stringLength;
+    } 
+
+    otherStringScore = totalCharacterScore / otherStringLength;
+
+    if(NSStringScoreOptionReducedLongStringPenalty == (options & NSStringScoreOptionReducedLongStringPenalty)){
+        // Reduce the penalty for longer words
+        CGFloat percentageOfMatchedString = otherStringLength / stringLength;
+        CGFloat wordScore = otherStringScore * percentageOfMatchedString;
+        finalScore = (wordScore + otherStringScore) / 2;
+
+    } else {
+        finalScore = ((otherStringScore * ((CGFloat)(otherStringLength) / (CGFloat)(stringLength))) + otherStringScore) / 2;
+    }
+
+    finalScore = finalScore / fuzzies;
+
+    if(startOfStringBonus && finalScore + 0.15 < 1){
+        finalScore += 0.15;
+    }
+
+    return finalScore;
+}
+
+@end