1 \documentclass{article}

     2 \documentclass{article}

     2 \usepackage{../style}

     3 \usepackage{../style}

     3 \usepackage{../langs}

     4 \usepackage{../langs}

     4 \usepackage{../grammar}

     5 \usepackage{../grammar}

     5 \usepackage{../graphics}

     6 \usepackage{../graphics}

   240 \end{lstlisting}

   241 \end{lstlisting}

   241 

   242 

   242 \noindent 

   243 \noindent 

   243 where $n_x$ is the index for the variable $x$.

   244 where $n_x$ is the index for the variable $x$.

   244 

   245 

   246 

   247 

   247 \begin{lstlisting}[mathescape,language={},numbers=none]

   248 \begin{lstlisting}[mathescape,language={},numbers=none]

   248 if $b$ then $cs_1$ else $cs_2$

   249 if $b$ then $cs_1$ else $cs_2$

   249 \end{lstlisting}

   250 \end{lstlisting}

   250 

   251 

   379 else-branch and then for the if-branch. However in the case

   380 else-branch and then for the if-branch. However in the case

   380 of while-loops this way of generating code still seems

   381 of while-loops this way of generating code still seems

   381 the most convenient.

   382 the most convenient.

   382 

   383 

   383 We are now ready to give the compile function for 

   384 We are now ready to give the compile function for 

   385 pair consisting of the code and an environment:

   386 pair consisting of the code and an environment:

   386 

   387 

   387 \begin{center}

   388 \begin{center}

   388 \begin{tabular}{lcl}

   389 \begin{tabular}{lcl}

   389 $\textit{compile}(\pcode{if}\;b\;\pcode{then}\; cs_1\;\pcode{else}\; cs_2, E)$ & $\dn$\\ 

   390 $\textit{compile}(\pcode{if}\;b\;\pcode{then}\; cs_1\;\pcode{else}\; cs_2, E)$ & $\dn$\\ 

   640 simple While-programs. In a real compiler, we would of course

   641 simple While-programs. In a real compiler, we would of course

   641 need to work harder and find out appropriate values for the

   642 need to work harder and find out appropriate values for the

   642 stack and local variables.

   643 stack and local variables.

   643 

   644 

   644 To sum up, in Figure~\ref{test} is the complete code generated

   645 To sum up, in Figure~\ref{test} is the complete code generated

   646 

   647 

   647 \begin{lstlisting}[mathescape,language=While]

   648 \begin{lstlisting}[mathescape,language=While]

   648 x := 1 + 2;

   649 x := 1 + 2;

   649 write x

   650 write x

   650 \end{lstlisting}

   651 \end{lstlisting}