1. A Canticle for Diff3

    A brief and not necessarily totally accurate history of diff3

    Diff3 is one of the most amazing, historic pieces of software in use today. It is an amazingly simple idea which changed the way we think about software. And even most of the people who use it don't really ...

    read more
  2. Fibonacci Regex Perversity

    Repeated Substitutions

    Consider these two regex substitutions:

    s/fi?b/i/
    s/fii(i*)b/f$1bfi$1b/
    

    (For those unfamiliar with Perlish regexes: that first one says “replace the string fb or fib with the string i”. The second one says “replace a string fiiXb with fXbfiXb, where X ...

    read more