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@@ -6109,12 +6109,11 @@ and the linear scan of \citet{Poletto:1999uq} may be more appropriate.
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The \LangInt{} and \LangVar{} languages only have a single kind of
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value, integers. In this chapter we add a second kind of value, the
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Booleans, to create the \LangIf{} language. The Boolean values
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-\emph{true} and \emph{false} are written \racket{\key{\#t}}\python{\key{True}}
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-and \racket{\key{\#f}}\python{\key{False}}
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+\emph{true} and \emph{false} are written \TRUE{} and \FALSE{}
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respectively in \racket{Racket}\python{Python}.
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The \LangIf{} language includes several
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-operations that involve Booleans (\key{and}, \key{not}, \racket{\key{eq?}}\python{==}, \key{<}, etc.) and the conditional \key{if} expression. With the
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-addition of \key{if}, programs can have non-trivial control flow which
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+operations that involve Booleans (\key{and}, \key{not}, \racket{\key{eq?}}\python{==}, \key{<}, etc.) and the \key{if} expression \python{and statement}.
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+With the addition of \key{if}, programs can have non-trivial control flow which
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\racket{impacts \code{explicate\_control} and liveness analysis}
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\python{impacts liveness analysis and motivates a new pass named
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\code{explicate\_control}}. Also, because
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@@ -6169,7 +6168,7 @@ checking and build a type checker for \LangIf{}
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%
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The remaining sections of this chapter discuss how our compiler passes
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change to accommodate Booleans and conditional control flow. There is
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-one new pass, named \code{shrink}, that translates some operators into
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+a new pass, named \code{shrink}, that translates some operators into
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others, thereby reducing the number of operators that need to be
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handled in later passes.
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%
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@@ -6193,30 +6192,33 @@ to handle conditional jumps.
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The concrete syntax of the \LangIf{} language is defined in
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Figure~\ref{fig:Rif-concrete-syntax} and the abstract syntax is defined
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in Figure~\ref{fig:Rif-syntax}. The \LangIf{} language includes all of
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-\LangVar{} (shown in gray), the Boolean literals \code{\#t} and
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-\code{\#f}, and the conditional \code{if} expression. We expand the
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+\LangVar{}\racket{(shown in gray)}, the Boolean literals \TRUE{} and
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+\FALSE{}, and the \code{if} expression \python{and statement}. We expand the
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operators to include
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\begin{enumerate}
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\item subtraction on integers,
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\item the logical operators \key{and}, \key{or} and \key{not},
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-\item the \key{eq?} operation for comparing two integers or two Booleans, and
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+\item the \racket{\key{eq?} operation}\python{\key{==} and \key{!=} operations}
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+ for comparing two integers or two Booleans for equality, and
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\item the \key{<}, \key{<=}, \key{>}, and \key{>=} operations for
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comparing integers.
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\end{enumerate}
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-We reorganize the abstract syntax for the primitive operations in
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-Figure~\ref{fig:Rif-syntax}, using only one grammar rule for all of
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-them. This means that the grammar no longer checks whether the arity
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-of an operators matches the number of arguments. That responsibility
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-is moved to the type checker for \LangIf{}, which we introduce in
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-Section~\ref{sec:type-check-Rif}.
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+
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+\racket{We reorganize the abstract syntax for the primitive
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+ operations in Figure~\ref{fig:Rif-syntax}, using only one grammar
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+ rule for all of them. This means that the grammar no longer checks
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+ whether the arity of an operators matches the number of
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+ arguments. That responsibility is moved to the type checker for
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+ \LangIf{}, which we introduce in Section~\ref{sec:type-check-Rif}.}
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\begin{figure}[tp]
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\centering
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\fbox{
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\begin{minipage}{0.96\textwidth}
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+{\if\edition\racketEd\color{olive}
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\[
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\begin{array}{lcl}
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- \itm{bool} &::=& \key{\#t} \MID \key{\#f} \\
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+ \itm{bool} &::=& \TRUE \MID \FALSE \\
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\itm{cmp} &::= & \key{eq?} \MID \key{<} \MID \key{<=} \MID \key{>} \MID \key{>=} \\
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\Exp &::=& \gray{ \Int \MID \CREAD{} \MID \CNEG{\Exp} \MID \CADD{\Exp}{\Exp} } \MID \CSUB{\Exp}{\Exp} \\
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&\MID& \gray{ \Var \MID \CLET{\Var}{\Exp}{\Exp} } \\
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@@ -6227,6 +6229,20 @@ Section~\ref{sec:type-check-Rif}.
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\LangIfM{} &::=& \Exp
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\end{array}
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\]
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+\fi}
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+{\if\edition\pythonEd\color{purple}
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+\[
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+\begin{array}{rcl}
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+ \itm{binop} &::= & \key{+} \MID \key{-} \MID \key{==} \MID \key{!=} \MID \key{<} \MID \key{<=} \MID \key{>} \MID \key{>=} \\
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+ \itm{uniop} &::= & \key{-} \MID \key{not} \\
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+ \Exp &::=& \Int \MID \key{input\_int}\LP\RP \MID \itm{uniop}\;\Exp \MID \Exp \; \itm{binop} \; \Exp \MID \Var{} \\
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+ &\MID& \TRUE \MID \FALSE \MID \Exp\;\key{if}\;\Exp\;\key{else}\;\Exp\\
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+ \Stmt &::=& \key{print}\LP \Exp \RP \MID \Exp \MID \Var\mathop{\key{=}}\Exp
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+ \MID \key{if}\; \Exp \;\key{:}\; \Stmt^{+} \;\key{else:}\; \Stmt^{+}\\
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+ \LangVarM{} &::=& \Stmt^{*}
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+\end{array}
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+\]
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+\fi}
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\end{minipage}
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}
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\caption{The concrete syntax of \LangIf{}, extending \LangVar{}
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@@ -6238,6 +6254,7 @@ Section~\ref{sec:type-check-Rif}.
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\centering
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\fbox{
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\begin{minipage}{0.96\textwidth}
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+{\if\edition\racketEd\color{olive}
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\[
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\begin{array}{lcl}
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\itm{bool} &::=& \code{\#t} \MID \code{\#f} \\
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@@ -6250,6 +6267,27 @@ Section~\ref{sec:type-check-Rif}.
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\LangIfM{} &::=& \PROGRAM{\code{'()}}{\Exp}
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\end{array}
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\]
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+\fi}
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+{\if\edition\pythonEd\color{purple}
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+\[
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+\begin{array}{lcl}
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+\itm{binop} &::=& \code{Add()} \MID \code{Sub()} \\
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+\itm{uniop} &::=& \code{USub()} \MID \code{Not()} \\
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+\itm{bool} &::=& \code{True} \MID \code{False} \\
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+\itm{boolop} &::=& \code{And()} \MID \code{Or()} \\
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+\itm{cmp} &::= & \code{Eq()} \MID \code{NotEq()} \MID \code{Lt()} \MID \code{LtE()} \MID \code{Gt()} \MID \code{GtE()} \\
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+\Exp &::=& \INT{\Int} \MID \READ{} \MID \VAR{\Var} \\
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+ &\MID& \BINOP{\Exp}{\itm{binop}}{\Exp}
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+ \MID \UNIOP{\itm{uniop}}{\Exp}\\
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+ &\MID& \CMP{\Exp}{\itm{cmp}}{\Exp}
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+ \MID \BOOLOP{\itm{boolop}}{\Exp}{\Exp}\\
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+ &\MID& \BOOL{\itm{bool}} \MID \IF{\Exp}{\Exp}{\Exp} \\
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+\Stmt{} &::=& \PRINT{\Exp} \MID \EXPR{\Exp} \\
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+ &\MID& \ASSIGN{\VAR{\Var}}{\Exp} \MID \IFSTMT{\Exp}{\Stmt^{*}}{\Stmt^{*}}\\
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+\LangIfM{} &::=& \PROGRAM{\code{'()}}{\Stmt^{*}}
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+\end{array}
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+\]
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+\fi}
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\end{minipage}
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}
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\caption{The abstract syntax of \LangIf{}.}
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Jeremy Siek