The double spaces only serve as a presentational quirk, too. The amount of space after the sentence ends does not determine whether or not it has ended. Most ma

The double spaces only serve as a presentational quirk, too. The amount of space after the sentence ends does not determine whether or not it has ended. Most mass-produced material no longer uses longer spaces after the end of a sentence, and websites require CSS or the use of special character entities to produce longer spaces, so it follows that most people do not require double spaces when reading as an indication that the sentence has ended. The sequence "period space space" is also not reliable for a computer to determine the end of a sentence, either, so in building a lexer you would likely remove the consecutive spaces (outside of content that is marked as pre-formatted) and use some other method of determining whether a period is being used for an abbreviation, the end of a sentence, or some other purpose. In fact, you might even throw out the period, since it is no longer a necessary part of the content (though the parser would add it back in for output in most situations).