Created
November 6, 2014 21:37
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String extension that returns a new string with matches of a regex replaced by a transformation
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| extension String { | |
| func replace(regularExpression: NSRegularExpression, transform: (String) -> String) -> String { | |
| var output = "" | |
| var lastMatchedLocation = self.startIndex | |
| let rangeAll = NSMakeRange(0, countElements(self)); | |
| regularExpression.enumerateMatchesInString(self, options: NSMatchingOptions(0), range: rangeAll) { | |
| (result: NSTextCheckingResult!, _, _) in | |
| // Result matched range | |
| let start = advance(self.startIndex, result.range.location) | |
| let end = advance(start, result.range.length) | |
| let matchedRange = Range(start: start, end: end) | |
| // Range of the unmatched string preceding | |
| let unmatchedPrecedingRange = Range(start: lastMatchedLocation, end: start) | |
| lastMatchedLocation = end | |
| // Add the transformed string to the output | |
| let unmatchedPrecedingString = self.substringWithRange(unmatchedPrecedingRange) | |
| let matchedTransformedString = transform(self.substringWithRange(matchedRange)) | |
| output += unmatchedPrecedingString + matchedTransformedString | |
| } | |
| // Add the unmatched remaining to the output | |
| let unmatchedRemainingRange = Range(start: lastMatchedLocation, end: self.endIndex) | |
| let unmatchedRemainingString = self.substringWithRange(unmatchedRemainingRange) | |
| output += unmatchedRemainingString | |
| return output | |
| } | |
| } |
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