Get all 100 point values from unix dictionary

//: Playground - noun: a place where people can play
import Cocoa

// Generate the appropriate integer value for each character using
// a the ascii value from the return unicodeScalars.
// UInt8 (Unsigned 8 bit Integer)
// a | A = 1
// z | Z = 26
// all others will be 0
extension Character {
  var letterValue: Int {
    // We only want to give a value to the characters a-z and A-Z.
    guard let scaler = self.unicodeScalars.first else { return 0 }
    let value = Int(UInt8(ascii: scaler))

    // unicodeScalars ascii values
    // a = 97
    // z = 122
    // A = 65
    // Z = 90
    let uppercaseOffset = 64
    let lowercaseOffset = 96

    // Uppercase letters
    if (value >= 65) && (value <= 90) {
      return value - uppercaseOffset
    }
    
    // lowercase letters
    if (value >= 97) && (value <= 122) {
      return value - lowercaseOffset
    }

    // character was outside of the a-z | A-Z characger set and it has no value.
    return 0
  }
}

extension  String {
  // return the value for a string, assuming it is a word.
  var wordValue: Int {
    return self.map { $0.letterValue }
               .reduce(0, +)
  }
  
  // break a string into words by spliting on a space character.
  var words: [String] {
    // TODO: handle complex words with spaces i.e.: names like Mc Donald
    return self.components(separatedBy:" ")
  }

  // break a string into lines of string by spliting on a new line character.
  var lines: [String] {
    // TODO: handle other line endings
    return self.components(separatedBy:"\n")
  }

}

do {
  let dictionary = try String(contentsOfFile: "/usr/share/dict/web2")
  let wordsWithValue100 = dictionary.lines.filter { $0.wordValue == 100 }
  print("Dictionary has " + String(wordsWithValue100.count) + " words that equal 100.") // Dictionary has 2302 words that equal 100.

} catch {
  print("Failed to read the dictionary")
}

Dictionary has 2302 words that equal 100