RNATranscriptionExample.m in trackler-2.2.1.20

- old
+ new
@@ -6,41 +6,20 @@
 {
     NSDictionary *dnaToRNADict = @{ @"G" : @"C",
                                     @"C" : @"G",
                                     @"T" : @"A",
                                     @"A" : @"U" };
-    
-    NSArray *dnaKeys = [dnaToRNADict allKeys];
-    NSString *dnaKeyString = [dnaKeys componentsJoinedByString:@""];
-    NSCharacterSet *invertedSet = [[NSCharacterSet characterSetWithCharactersInString:dnaKeyString] invertedSet];
-    NSRange invertedSetRange = [dnaStrand rangeOfCharacterFromSet:invertedSet];
-    if (invertedSetRange.location != NSNotFound) {
-        return nil;
+
+    NSMutableString *rnaStrand = [NSMutableString stringWithString:dnaStrand];
+
+    for (NSUInteger i = 0; i < [dnaStrand length]; i++) {
+        NSRange charRange = [dnaStrand rangeOfComposedCharacterSequenceAtIndex:i];
+        NSString *dnaNucleotide = [dnaStrand substringWithRange:charRange];
+        NSString *rnaNucleotide = dnaToRNADict[dnaNucleotide];
+        if (!rnaNucleotide) return nil;
+        [rnaStrand replaceCharactersInRange:charRange withString:rnaNucleotide];
     }
-    
-    NSMutableString *rna = [NSMutableString stringWithString:dnaStrand];
-    NSMutableDictionary *dnaToRnaRanges = [NSMutableDictionary dictionary];
-    
-    [[dnaToRNADict allKeys] enumerateObjectsUsingBlock:^(NSString *dnaKey, NSUInteger idx, BOOL * _Nonnull stop) {
-        NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:dnaKey options:0 error:NULL];
-        NSMutableArray *ranges = [NSMutableArray array];
-        
-        [regex enumerateMatchesInString:dnaStrand options:0 range:NSMakeRange(0, [dnaStrand length]) usingBlock:^(NSTextCheckingResult * _Nullable match, NSMatchingFlags flags, BOOL * _Nonnull stop) {
-            NSRange range = [match rangeAtIndex:0];
-            [ranges addObject:[NSValue valueWithRange:range]];
-        }];
-        
-        dnaToRnaRanges[dnaKey] = [ranges copy];
-    }];
-    
-    [dnaToRNADict enumerateKeysAndObjectsUsingBlock:^(NSString *dnaKey, NSString *rnaValue, BOOL * _Nonnull stop) {
-        NSArray *dnaRanges = dnaToRnaRanges[dnaKey];
-        
-        [dnaRanges enumerateObjectsUsingBlock:^(NSValue *dnaRangeValue, NSUInteger idx, BOOL * _Nonnull stop) {
-            [rna replaceOccurrencesOfString:dnaKey withString:rnaValue options:NSLiteralSearch range:[dnaRangeValue rangeValue]];
-        }];
-    }];
-    
-    return [rna copy];
+
+    return [rnaStrand copy];
 }
 
 @end