Edits to regex warmup

Misc/Warm-Ups/regex.tex

@@ -58,10 +58,10 @@
 	The pattern \htexttt{linea?r} will match only \texttt{linear} and \texttt{liner} \\
 	\vspace{2mm}
 
-	Patterns with brackets \htexttt{\{min, max\}} are the most flexible quantifier. \\
+	Brackets \htexttt{\{min, max\}} are the most flexible quantifier. \\
 	They specify exactly how many tokens to match: \\
 	\htexttt{ab\{2\}a} will match only \texttt{abba}. \\
-	\htexttt{ab\{1,3\}a} will match \texttt{aba}, \texttt{abba}, \texttt{abbba}. \\
+	\htexttt{ab\{1,3\}a} will match \texttt{aba}, \texttt{abba}, and \texttt{abbba}. \\
 	\htexttt{ab\{2,\}a} will match any \texttt{ab...ba} with at least two \texttt{b}s.
 
 	\vspace{5mm}
@@ -81,11 +81,8 @@
 
 
 
-	\textbf{Characters, Sets, and Groups}
-
-	Characters tell us what to match.
-
-	Usually we specify them literally, as shown above: \\
+	\textbf{Characters, Sets, and Groups} \\
+	We specify characters literally, as shown above: \\
 	\texttt{a+} means \say{one or more \texttt{a} character} \\
 
 	\vspace{2mm}
@@ -97,6 +94,8 @@
 	The first such way is the \textit{set}, denoted \htexttt{[ ]}. A set can pretend to be any character inside it. \\
 	For example, \htexttt{m[aoy]th} will match \texttt{math}, \texttt{moth}, or \texttt{myth}. \\
 	\htexttt{a[01]+b} will match \texttt{a0b}, \texttt{a111b}, \texttt{a1100110b}, and any other similar string. \\
+	You may negate a set with a \htexttt{\textasciicircum}. \\
+	\htexttt{[\textasciicircum abc]} will match any character except \texttt{a}, \texttt{b}, or \texttt{c}, including symbols and spaces.
 
 	\vspace{2mm}
 
@@ -110,16 +109,29 @@
 
 	\problem{}<regex>
 	You are now familiar with most of the tools regex has to offer. \\
-	Match the following strings:
-	\begin{enumerate}
+	Write patterns that match the following strings:
+	\begin{enumerate}[itemsep=1mm]
 		\item An ISO-8601 date, like \texttt{2022-10-29}. \\
-		Invalid dates like \texttt{2022-13-29} should also be matched. \\
+		\hint{Invalid dates like \texttt{2022-13-29} should also be matched.}
+
+		\item An email address. \\
+		\hint{Don't forget about subdomains, like \texttt{math.ucla.edu}.}
+
+		\item A UCLA room number, like \texttt{MS 5118} or \texttt{Kinsey 1220B}.
 
-		\item A hexadecimal integer of any length.
-		\item A UCLA room number, like \texttt{MS 5118} or \texttt{Kinsey 1220B}
 		\item Any ISBN-10 of the form \texttt{0-316-00395-7}. \\
-		Remember that the check digit can be an \texttt{X}. \\
-		Dashes are optional.
+		\hint{Remember that the check digit may be an \texttt{X}. Dashes are optional.}
+
+		\item A word of even length. \\
+		\hint{The set \texttt{[A-z]} contains every english letter, capitalized and lowercase. \\
+		\texttt{[a-z]} will only match lowercase letters.}
+
+		\item A word with exactly 3 vowels. \\
+		\hint{The special token \texttt{\textbackslash w} will match any word character. It is equivalent to \texttt{[A-z0-9\_]}}
+
+		\item A word that has even length and exactly 3 vowels.
+
+		\item A sentence that does not start with a capital letter.
 	\end{enumerate}
 
 
@@ -131,15 +143,6 @@
 
 
 	\problem{}
-	If you'd like to know more, check out \texttt{regexr.com}. There's an interative regex prompt that provices explanations, as well as a cheatsheet that explains every regex token there is. You can find a nice set of challenges at \texttt{http://regex.alf.nu} \\
+	If you'd like to know more, check out \texttt{regexr.com}. It offers an interative regex prompt, as well as a cheatsheet that explains every other regex token there is. You can find a nice set of challenges at \texttt{http://regex.alf.nu}. \\
 	I especially encourage you to look into this if you are interested in computer science.
-	\pagebreak
-
-	\problem{}
-	Draw a DFA for each of the following regex strings. \\
-	\begin{itemize}
-		\item Your solution to \ref{regex}, Part 2
-		\item Your solution to \ref{regex}, Part 3
-		\item Your solution to \ref{regex}, Part 4
-	\end{itemize}
 \end{document}