diff -r 357c395ae838 -r e74c696821a2 handouts/ho01.tex --- a/handouts/ho01.tex Tue Aug 23 15:38:20 2016 +0200 +++ b/handouts/ho01.tex Tue Aug 23 23:12:55 2016 +0200 @@ -256,8 +256,15 @@ \url{http://stackstatus.net/post/147710624694/outage-postmortem-july-20-2016} \end{center} +\noindent I can also highly recommend a cool webtalk from an engineer +from Stack Exchange on the same subject: + +\begin{center} +\url{https://vimeo.com/112065252} +\end{center} + \noindent -It was also a problem in the Atom editor +A similar problem also occured in the Atom editor: \begin{center} \url{http://davidvgalbraith.com/how-i-fixed-atom/} @@ -564,15 +571,15 @@ regular expressions. They have been studied for the last 60 years (by smarter people than me)---surely nothing new can be found out about them. I even have the vague recollection that -I did not quite understand them during my study. If I remember +I did not quite understand them during my undergraduate study. If I remember correctly,\footnote{That was really a long time ago.} I got utterly confused about $\ONE$ (which my lecturer wrote as $\epsilon$) and the empty string.\footnote{Obviously the -lecturer must have been bad.} Since my study, I have used +lecturer must have been bad.} Since my then, I have used regular expressions for implementing lexers and parsers as I have always been interested in all kinds of programming languages and compilers, which invariably need regular -expression in some form or shape. +expressions in some form or shape. To understand my fascination \emph{nowadays} with regular expressions, you need to know that my main scientific interest @@ -603,7 +610,7 @@ proposed by Sulzmann and Lu in 2014.\footnote{\url{http://goo.gl/bz0eHp}} Hopefully we can prove that the machine code(!) -that implements this code efficiently is correct. Writing +that implements this code efficiently is correct also. Writing programs in this way does not leave any room for potential errors or bugs. How nice! @@ -625,10 +632,10 @@ To conclude: Despite my early ignorance about regular expressions, I find them now very interesting. They have a beautiful mathematical theory behind them, which can be -sometimes quite deep and which contains hidden snares. They have +sometimes quite deep and which sometimes contains hidden snares. They have practical importance (remember the shocking runtime of the regular expression matchers in Python, Ruby and Java in some -instances) and the problems in Stack Exchange and the Atom editor. +instances and the problems in Stack Exchange and the Atom editor). People who are not very familiar with the mathematical background of regular expressions get them consistently wrong. The hope is that we can do better in the