String extensions to make my life more convenient. When I remember them…

String+Hishma.swift

extension String {
    /// Replace all instances of characters in a character set.
    ///
    /// - Parameters:
    ///   - characterSet: The `CharacterSet` containing the characters to replace in the string.
    ///   - replacementString: The `String` to replace the matched characters with.
    /// - Returns: A new `String` with all characters in the character set replaced by the replacement string.
    func replacingCharacters(in characterSet: CharacterSet, with replacementString: String = "") -> String {
        return self.components(separatedBy: characterSet).joined(separator: replacementString)
    }
    
    /// Sparate a string by word boundaries.
    ///
    /// - Returns: An array of strings, representing a list of words.
    func words() -> [String] {
        return self.substrings(options: .byWords)
    }
    
    /// Sparate a string by sentences.
    ///
    /// - Returns: An array of strings, representing a list of sentences.
    func sentences() -> [String] {
        return self.substrings(options: .bySentences)
    }
    
    /// Sparate a string by paragraphs.
    ///
    /// - Returns: An array of strings, representing a list of paragraphs.
    func paragraphs() -> [String] {
        return self.substrings(options: .byParagraphs)
    }
    
    /// Sparate a string by lines.
    ///
    /// - Returns: An array of strings, representing a list of lines.
    func lines() -> [String] {
        return self.substrings(options: .byLines)
    }
    
    /// Sparate a string eumeration options.
    ///
    /// - Parameter options: Options specifying types of substrings and enumeration styles. If opts is omitted or empty, body is called a single time with the range of the string specified by range.
    /// - Returns: Array of strings, separated by the specified options.
    func substrings(options: NSString.EnumerationOptions) -> [String] {
        let range: Range<String.Index> = self.startIndex ..< self.endIndex
        var substrings = [String]()
        self.enumerateSubstrings(in: range, options: options) {substr,_,_,_ in
            guard let substring = substr, !substring.isEmpty else { return }
            substrings.append(substring)
        }
        return substrings
    }
}

extension String: Error {}

/// Returns the string as the error description
extension String: LocalizedError {
    public var errorDescription: String? { return self }
}

extension String {
    /// Prepend a string to a string, you know, like amend but on the other end.
    public mutating func prepend(_ other: String) {
        self = other + self
    }
}

extension String {
    public mutating func prepend(_ other: String) {
        self = other + self
    }
}