Binary file cws/cw01.pdf has changed

Binary file cws/cw02.pdf has changed

--- a/cws/cw02.tex	Fri Oct 11 19:13:00 2024 +0100
+++ b/cws/cw02.tex	Wed Oct 16 13:14:13 2024 +0100
@@ -13,12 +13,20 @@
 WHILE language. You can do the implementation in any programming
 language you like, but you need to submit the source code with which
 you answered the questions, otherwise a mark of 0\% will be
-awarded. You need to submit your written answers as pdf---see attached
-questionaire.  Code send as code. If you use Scala in your code, a
+awarded. %You need to submit your written answers as pdf---see attached
+% questionaire.  Code send as code.
+If you use Scala in your code, a
 good place to start is the file \texttt{lexer.sc} and
 \texttt{token.sc} uploaded to KEATS. The template file on Github is
-called \texttt{cw02.sc}. Your code needs to be uploaded to Github by
-the deadline.
+called \texttt{cw02.sc}. The example files are in the subdirectory
+\texttt{examples}. The main function that will be tested is
+called \texttt{tokenise}. The marks will be distributed such that
+3 marks are given for the correct \texttt{WHILE\_REGS} regular
+expression; 5 marks for the correct \texttt{inj} and \texttt{mkeps}
+definitions; and two marks when \texttt{tokenise} produces the correct
+results for the example files. 
+
+
 
 \subsection*{Disclaimer\alert}
 
@@ -140,9 +148,9 @@
 this you need to implement the functions $nullable$ and $der$
 (you can use your code from CW~1), as well as $mkeps$ and
 $inj$. These functions need to be appropriately extended for
-the extended regular expressions from Q1. Write down in the
-questionaire at the end the 
-clauses for
+the extended regular expressions from Q1. The definitions
+you need to create are:
+
 
 \begin{center}
 \begin{tabular}{@ {}l@ {\hspace{2mm}}c@ {\hspace{2mm}}l@ {}}
@@ -176,94 +184,99 @@
 
 
 Also add the record regular expression from the
-lectures to your lexer and implement a function, say
-\pcode{env}, that returns all assignments from a value (such
-that you can extract easily the tokens from a value).\medskip 
+lectures to your lexer and complete the function
+\pcode{env} so that it returns all assignments from a value (this then 
+allows you to extract easily the tokens from a value in the next
+question).\medskip 
 
 \noindent
-Finally give \textbf{all} the tokens for your regular expressions from Q1 and the
-string
+Finally make that the function \texttt{lexing\_simp} generates
+with the regular expression from Q1 for the string
 
 \begin{center}
 \code{"read n;"}
 \end{center} 
 
 \noindent
-and use your \pcode{env} function to give the token sequence.
+the following pairs:
+
+\begin{center}
+\texttt{List((k,read), (w, ), (i,n), (s,;))}
+\end{center} 
+
+
+
 
 
 \subsection*{Question 3}
 
-Extend your lexer from Q2 to also simplify regular expressions after
-each derivation step and rectify the computed values after each
-injection. Use this lexer to tokenize six WHILE programs some of which
-are given in Figures~\ref{fib} -- \ref{collatz}. You can find these programms also on
-Github under the \texttt{cw2} directory. Give the tokens of these
-programs where whitespaces and comments are
-filtered out. Make sure you can tokenise \textbf{exactly} these
-programs.\bigskip
+Make sure your lexer from Q2 also simplifies regular expressions after
+each derivation step and rectifies the computed values after each
+injection. Use this lexer to tokenise the six WHILE programs
+in the \texttt{examples} directory. Make sure that the \texttt{tokenise}
+function filters out whitespaces and comments.\bigskip
 
 
-\begin{figure}[h]
-\mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/fib.while}}
-\caption{Fibonacci program in the WHILE language.\label{fib}}
-\end{figure}
+% \begin{figure}[h]
+% \mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/fib.while}}
+% \caption{Fibonacci program in the WHILE language.\label{fib}}
+% \end{figure}
 
-\begin{figure}[h]
-\mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/loops.while}}
-\caption{The three-nested-loops program in the WHILE language. 
-(Usually used for timing measurements.)\label{loop}}
-\end{figure}
+% \begin{figure}[h]
+% \mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/loops.while}}
+% \caption{The three-nested-loops program in the WHILE language. 
+% (Usually used for timing measurements.)\label{loop}}
+% \end{figure}
 
-\begin{figure}[h]
-\mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/factors.while}}
-\caption{A program that calculates factors for numbers in the WHILE
-  language.\label{factors}}
-\end{figure}
+% \begin{figure}[h]
+% \mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/factors.while}}
+% \caption{A program that calculates factors for numbers in the WHILE
+%   language.\label{factors}}
+% \end{figure}
 
-\begin{figure}[h]
-\mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/collatz2.while}}
-\caption{A program that calculates the Collatz series for numbers
-  between 1 and 100.\label{collatz}}
-\end{figure}
+% \begin{figure}[h]
+% \mbox{\lstinputlisting[language=While,xleftmargin=10mm]{../cwtests/cw02/collatz2.while}}
+% \caption{A program that calculates the Collatz series for numbers
+%   between 1 and 100.\label{collatz}}
+% \end{figure}
 
-\clearpage
-\newpage
-\section*{Answers}
+% \clearpage
+% \newpage
+% \section*{Answers}
 
-\mbox{}
+% \mbox{}
 
-\noindent
-\textbf{Question 2:}\\ (Use mathematical notation, such as $r^+$, rather than code, such as \code{PLUS(r)})
+% \noindent
+% \textbf{Question 2:}\\ (Use mathematical notation, such as $r^+$, rather than code, such as \code{PLUS(r)})
 
-\begin{center}
-  \def\arraystretch{1.6}  
-\begin{tabular}{@ {}l@ {\hspace{2mm}}c@ {\hspace{2mm}}l@ {}}
-$mkeps([c_1,c_2,\ldots,c_n])$  & $\dn$ & \uline{\hspace{8cm}}\\
-$mkeps(r^+)$                   & $\dn$ & \uline{\hspace{8cm}}\\
-$mkeps(r^?)$                   & $\dn$ & \uline{\hspace{8cm}}\\
-$mkeps(r^{\{n\}})$             & $\dn$ & \uline{\hspace{8cm}}\bigskip\\
-$inj\, ([c_1,c_2,\ldots,c_n])\,c\,\ldots$  & $\dn$ & \uline{\hspace{8cm}}\\
-$inj\, (r^+)\,c\,\ldots$                   & $\dn$ & \uline{\hspace{8cm}}\\
-$inj\, (r^?)\,c\,\ldots$                   & $\dn$ & \uline{\hspace{8cm}}\\
-$inj\, (r^{\{n\}})\,c\,\ldots$             & $\dn$ & \uline{\hspace{8cm}}\\
-\end{tabular}
-\end{center}\bigskip
+% \begin{center}
+%   \def\arraystretch{1.6}  
+% \begin{tabular}{@ {}l@ {\hspace{2mm}}c@ {\hspace{2mm}}l@ {}}
+% $mkeps([c_1,c_2,\ldots,c_n])$  & $\dn$ & \uline{\hspace{8cm}}\\
+% $mkeps(r^+)$                   & $\dn$ & \uline{\hspace{8cm}}\\
+% $mkeps(r^?)$                   & $\dn$ & \uline{\hspace{8cm}}\\
+% $mkeps(r^{\{n\}})$             & $\dn$ & \uline{\hspace{8cm}}\bigskip\\
+% $inj\, ([c_1,c_2,\ldots,c_n])\,c\,\ldots$  & $\dn$ & \uline{\hspace{8cm}}\\
+% $inj\, (r^+)\,c\,\ldots$                   & $\dn$ & \uline{\hspace{8cm}}\\
+% $inj\, (r^?)\,c\,\ldots$                   & $\dn$ & \uline{\hspace{8cm}}\\
+% $inj\, (r^{\{n\}})\,c\,\ldots$             & $\dn$ & \uline{\hspace{8cm}}\\
+% \end{tabular}
+% \end{center}\bigskip
 
-\noindent
-Tokens for \code{"read n;"}\\
+% \noindent
+% Tokens for \code{"read n;"}\\
 
-\noindent
-\uline{\hfill}\medskip
+% \noindent
+% \uline{\hfill}\medskip
 
-\noindent
-\uline{\hfill}\medskip
+% \noindent
+% \uline{\hfill}\medskip
 
-\noindent
-\uline{\hfill}\medskip
+% \noindent
+% \uline{\hfill}\medskip
 
-\noindent
-\uline{\hfill}\medskip
+% \noindent
+% \uline{\hfill}\medskip
 
 
 \end{document}

Binary file cws/cw03.pdf has changed

--- a/cws/cw03.tex	Fri Oct 11 19:13:00 2024 +0100
+++ b/cws/cw03.tex	Wed Oct 16 13:14:13 2024 +0100
@@ -12,12 +12,22 @@
 
 \noindent This coursework is worth 10\% and is due on \cwTHREE{} at
 16:00. You are asked to implement a parser for the WHILE language and
-also an interpreter. The parser needs to use parser combinators.
-You can do the implementation in any programming
-language you like, but you need to submit the source code with which
-you answered the questions, otherwise a mark of 0\% will be
-awarded. You should use the lexer from the previous coursework for the
-parser.  Please submit your code to Github by the deadline.
+also an interpreter. The parser needs to use parser combinators.  You
+can do the implementation in any programming language you like, but
+you need to submit the source code with which you answered the
+questions, otherwise a mark of 0\% will be awarded. If you use Scala
+in your code, a good place to start is the file \texttt{comb1.sc} and
+\texttt{comb2.sc} uploaded to KEATS. Feel free to use the ``hack''
+explained during the lectures. This might make your grammar
+simpler. However, make sure you understand the code involved in the
+``hack'' because if you just do ``mix-and-match'' you will receive
+strange errors.  The main function that will be tested is called
+\texttt{eval} and \texttt{Stmts.parse\_all}. The latter expects a list
+of tokens as input and generates an AST. The former expects an AST and
+``runs'' the program. The marks will be distributed such that 6 marks
+are given for the correct grammar (and parsers); 4 marks for the correct
+\texttt{eval} function.  You should use the lexer from CW2 for the
+parser - you potentially need to make additions for CW2.  
 
 \subsection*{Disclaimer\alert}
 
@@ -29,6 +39,29 @@
 be tempted to ask Github Copilot for help or do any other
 shenanigans like this!
 
+\subsection*{Syntax Error in Template File cw03.sc\alert}
+
+Apologies, there is a small syntax error in the template file where a variable
+needs to be called \texttt{tks} instead of \texttt{tk}. The code
+in question is at the end of \texttt{cw03.sc} and should be like
+this (see lines 5, 6 and 8):
+
+\begin{lstlisting}[language=Scala,numbers=left]
+@main
+def test(file: String) = {
+  val contents = os.read(os.pwd / "examples" / file)
+  println(s"Lex $file: ")
+  val tks = tokenise(contents)
+  println(tks.mkString(","))
+  println(s"Parse $file: ")
+  val ast = Stmts.parse_all(tks).head
+  println(ast)
+  println(s"Eval $file: ")
+  println(eval(ast))
+}
+\end{lstlisting}  
+
+
 
 \subsection*{Question 1}
 
@@ -54,21 +87,13 @@
 \subsection*{Question 2}
 
 You should implement a parser for the WHILE language using parser
-combinators. Be careful that the parser takes as input a stream, or
-list, of \emph{tokens} generated by the tokenizer from the previous
+combinators. Be careful that the parser takes as input a list of
+\emph{tokens} generated by the tokenizer from the previous
 coursework. For this you might want to filter out whitespaces and
 comments. Your parser should be able to handle the WHILE programs in
-Figures~\ref{fib} -- \ref{collatz}.  In addition give the
-parse tree according to your grammar for the statement:
-
-\begin{lstlisting}[language=While,numbers=none]
-if (a < b) then skip else a := a * b + 1
-\end{lstlisting}
-
-\noindent
-The output of the parser is an abstract syntax tree (AST).
-A (possibly incomplete) datatype for ASTs of the WHILE language
-is shown in Figure~\ref{trees}.
+the \texttt{examples} directory.  The output of the parser is an
+abstract syntax tree (AST).  A (possibly incomplete) datatype for ASTs
+of the WHILE language is shown in Figure~\ref{trees}.
 
 \begin{figure}[p]
 \begin{lstlisting}[language=Scala]
@@ -133,8 +158,8 @@
 Note also that some programs contain a read-statement,
 which means you need to read and integer from the commandline
 and store the value in the corresponding variable.
-Programs you should be able to run are shown in
-Figures \ref{fib} -- \ref{collatz}. The output
+Programs you should be able to run are given in  the
+\texttt{examples} directory. The output
 of the \texttt{primes.while} should look as follows:
 
 \begin{figure}[h]
@@ -170,79 +195,6 @@
 \caption{Sample output for the file \texttt{primes.while}.\label{fib}}
 \end{figure}
 
-\noindent
-Give some time measurements for your interpreter
-and the loop program in Figure~\ref{loop}. For example
-how long does your interpreter take when \pcode{start}
-is initialised with 100, 500 and so on. How far can
-you scale this value if you are willing to wait, say
-1 Minute?
-
-\clearpage
-
-\begin{figure}[h]
-\lstinputlisting[language=while,xleftmargin=20mm]{../cwtests/cw03/fib.while}
-\caption{Fibonacci program in the WHILE language.\label{fib}}
-\end{figure}
-
-\begin{figure}[h]
-\lstinputlisting[language=while,xleftmargin=20mm]{../cwtests/cw03/loops.while}
-\caption{The three-nested-loops program in the WHILE language. 
-Usually used for timing measurements.\label{loop}}
-\end{figure}
-
-\begin{figure}[h]
-\lstinputlisting[language=while,xleftmargin=0mm]{../cwtests/cw03/primes.while}
-\caption{Prime number program.\label{primes}}
-\end{figure}
-
-
-\begin{figure}[p]
-\lstinputlisting[language=while,xleftmargin=0mm]{../cwtests/cw03/collatz2.while}
-\caption{Collatz series program.\label{collatz}}
-\end{figure}
-
-\clearpage
-\newpage
-\section*{Answers}
-
-\mbox{}  
-
-\noindent
-\textbf{Name:}\uline{\hfill}\bigskip
-
-
-
-\noindent
-\textbf{Question 1 (Grammar):}\\
-
-\mbox{}\\[9cm]
-
-\newpage
-\noindent
-\textbf{Question 2 (Parse Tree):}\\
-
-\mbox{}\\[8cm]
-
-
-\noindent
-\textbf{Question 3 (Timings):}\\
-
-\begin{center}
-  \def\arraystretch{1.5}
-  \begin{tabular}{l|l}
-    n & secs\\
-    \hline
-    100 & \\
-    500 & \\
-    700 & \\
-    1000 & \\
-    \\
-    \\
-    \\
-    \\
-   \end{tabular} 
-\end{center}  
 
 \end{document}
 

Binary file cws/cw04.pdf has changed

Binary file cws/cw05.pdf has changed

--- a/progs/matcher/cw1.sc	Fri Oct 11 19:13:00 2024 +0100
+++ b/progs/matcher/cw1.sc	Wed Oct 16 13:14:13 2024 +0100
@@ -122,6 +122,7 @@
 extension (r: Rexp) {
   def ~ (s: Rexp) = SEQ(r, s)
   def % = STAR(r)
+  def | (s: Rexp) = ALT(r, s)
 }
 
 

--- a/style.sty	Fri Oct 11 19:13:00 2024 +0100
+++ b/style.sty	Wed Oct 16 13:14:13 2024 +0100
@@ -91,11 +91,17 @@
 
 
 % CW deadlines
-\def\cwONE{16 October}
-\def\cwTWO{10 November}  
-\def\cwTHREE{27 November} 
-\def\cwFOUR{14 December}
-\def\cwFIVE{12 January}
+%\def\cwONE{16 October}
+%\def\cwTWO{10 November}  
+%\def\cwTHREE{27 November} 
+%\def\cwFOUR{14 December}
+%\def\cwFIVE{12 January}
+
+\def\cwONE{2nd January}
+\def\cwTWO{2nd January}  
+\def\cwTHREE{2nd January} 
+\def\cwFOUR{2nd January}
+\def\cwFIVE{2nd January}
 
 %%\def\cwISABELLE{11 December}