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\( % cbs-katex.sty % \newcommand{\STYLE}[2]{\htmlClass{cbs-#1}{#2}} \newcommand{\DECL}[3]{\htmlId{#1:#2}{#3}} \newcommand{\REF}[3]{\href{###1:#2}{#3}} \newcommand{\HYPER}[5]{\href{#1/#2/index.html###3:#4}{#5}} % \SHADE{MATH} can be defined to produce a shaded background to highlight % inline MATH in running text: \newcommand{\SHADE}[1]{#1} % \KEY{TEXT}, \STRING{TEXT}, \ATOM{TEXT}, \LEX{TEXT} can be used in math mode: \newcommand{\KEY}[1]{\textsf{\textit{\STYLE{Key}{#1}}}} \newcommand{\STRING}[1]{\textsf{``\texttt{#1}''}} \newcommand{\ATOM}[1]{\textsf{`\texttt{#1}'}} \newcommand{\LEX}[1]{\textsf{\STYLE{Key}{`}\texttt{#1}\STYLE{Key}{'}}} % The following commands produce ASCII characters that are treated specially by LaTeX: \newcommand{\HASH}{\char`\#} \newcommand{\DOLLAR}{\char`\$} \newcommand{\PERCENT}{\char`\%} \newcommand{\AMPERSAND}{\char`\&} \newcommand{\APOSTROPHE}{\char`\'} \newcommand{\BACKSLASH}{\char`\\} \newcommand{\CARET}{\char`\^} \newcommand{\UNDERSCORE}{\char`\_} \newcommand{\GRAVE}{\char`\`} \newcommand{\LEFTBRACE}{\char`\{} \newcommand{\RIGHTBRACE}{\char`\}} \newcommand{\TILDE}{\textasciitilde} % {\char`\~} % \NAME{name} highlights the name; % \NAMEDECL{name} declares Name.name as the target of links to name; % \NAMEREF{name} links name to the target Name.name in the current file; % \NAMEHYPER{url}{file}{name} links name to Name.name at url/file/file.pdf. % Similarly for \VAR{partvariable}, \SYN{syntaxname}, \SEM{semanticsName}, % and \SECT{sectionnumber} % The kerns in \SUB and \VAR avoid overlaps with primes: \newcommand{\SUB}[1]{_{\kern-2mu\STYLE{PartVariable}{\textsf{#1}}}} % PLAIN \newcommand{\VAR}[1]{\STYLE{PartVariable}{\textsf{\textit{#1}\kern2mu}}} \newcommand{\NAME}[1]{\STYLE{Name}{\textsf{#1}}} \newcommand{\SYN}[1]{\STYLE{SyntaxName}{\textsf{#1}}} \newcommand{\SEM}[1]{\STYLE{SemanticsName}{\textsf{#1}}} \newcommand{\SECT}[1]{\STYLE{SectionNumber}{\textsf{#1}}} % DECL \newcommand{\VARDECL}[1]{\DECL{PartVariable}{#1}{\VAR{#1}}} \newcommand{\NAMEDECL}[1]{\DECL{Name}{#1}{\NAME{#1}}} \newcommand{\SYNDECL}[1]{\DECL{SyntaxName}{#1}{\SYN{#1}}} \newcommand{\SEMDECL}[1]{\DECL{SemanticsName}{#1}{\SEM{#1}}} \newcommand{\SECTDECL}[1]{\DECL{SectionNumber}{#1}{\textsf{#1}}} % REF \newcommand{\VARREF}[1]{\REF{PartVariable}{#1}{\VAR{#1}}} \newcommand{\NAMEREF}[1]{\REF{Name}{#1}{\NAME{#1}}} \newcommand{\SYNREF}[1]{\REF{SyntaxName}{#1}{\SYN{#1}}} \newcommand{\SEMREF}[1]{\REF{SemanticsName}{#1}{\SEM{#1}}} \newcommand{\SECTREF}[1]{\REF{SectionNumber}{#1}{\SECT{#1}}} % HYPER \newcommand{\VARHYPER}[3]{\HYPER{#1}{#2}{PartVariable}{#3}{\VAR{#3}}} \newcommand{\NAMEHYPER}[3]{\HYPER{#1}{#2}{Name}{#3}{\NAME{#3}}} \newcommand{\SYNHYPER}[3]{\HYPER{#1}{#2}{SyntaxName}{#3}{\SYN{#3}}} \newcommand{\SEMHYPER}[3]{\HYPER{#1}{#2}{SemanticsName}{#3}{\SEM{#3}}} \newcommand{\SECTHYPER}[3]{\HYPER{#1}{#2}{SectionNumber}{#3}{\SECT{#3}}} % \LEFTPHRASE MATH \RIGHTPHRASE produces [[ MATH ]] with proper brackets: \newcommand{\LEFTPHRASE}{\llbracket} \newcommand{\RIGHTPHRASE}{\rrbracket} % \LEFTGROUP MATH \RIGHTGROUP produces ( MATH ) where the parentheses are % highlighted the same as keywords: \newcommand{\LEFTGROUP}{\STYLE{Key}{(}} \newcommand{\RIGHTGROUP}{\STYLE{Key}{)}} % MATH\PLUS produces a superscript + % MATH\STAR produces a superscript * % MATH\QUERY produces a superscript ? \newcommand{\PLUS}{{}^{\texttt{+}}} \newcommand{\STAR}{{}^{\texttt{*}}} \newcommand{\QUERY}{{}^{\texttt{?}}} % \RULE{& PREMISE \\ & ...}{& FORMULA ... \\ & ...} produces an inference rule % with separately aligned premises and conclusion % PREMISE % ... % ----------- % FORMULA ... % ... \newcommand{\RULE}[2] {\frac{\begin{aligned}#1\end{aligned}}{\begin{aligned}#2\end{aligned}}} % \AXIOM{& FORMULA ... \\ & ...} produces an aligned formula % % FORMULA ... % ... \newcommand{\AXIOM}[1]{\begin{aligned}#1\end{aligned}} % \TO TYPE produces => TYPE \newcommand{\TO}{\mathop{\Rightarrow}} % TERM \TRANS TERM produces TERM ---> TERM \newcommand{\TRANS}{\longrightarrow} % TERM \xrightarrow{LABEL} TERM puts the label above the long arrow % \)

Funcons-beta : Abrupting.cbs | PLAIN | PDF


Abruptly terminating

\[\begin{align*} [ \ \KEY{Funcon} \quad & \NAMEREF{stuck} \\ \KEY{Entity} \quad & \NAMEREF{abrupted} \\ \KEY{Funcon} \quad & \NAMEREF{finalise-abrupting} \\ \KEY{Funcon} \quad & \NAMEREF{abrupt} \\ \KEY{Funcon} \quad & \NAMEREF{handle-abrupt} \\ \KEY{Funcon} \quad & \NAMEREF{finally} \ ] \end{align*}\] \[\begin{align*} \KEY{Meta-variables} \quad & \VAR{T}, \VAR{T}', \VAR{T}'' <: \NAMEHYPER{../../../Values}{Value-Types}{values} \end{align*}\] \[\begin{align*} \KEY{Funcon} \quad & \NAMEDECL{stuck} : \TO \NAMEHYPER{../../../Values}{Value-Types}{empty-type} \end{align*}\]

\(\SHADE{\NAMEREF{stuck}}\) does not have any computation. It is used to represent the result of a transition that causes the computation to terminate abruptly.

\[\begin{align*} \KEY{Entity} \quad & \_ \xrightarrow{\NAMEDECL{abrupted}(\_ : \NAMEHYPER{../../../Values}{Value-Types}{values}\QUERY)} \_ \end{align*}\]

\(\SHADE{\NAMEREF{abrupted} ( \VAR{V} )}\) in a label on a tranistion indicates abrupt termination for reason \(\SHADE{\VAR{V}}\). \(\SHADE{\NAMEREF{abrupted} ( \ )}\) indicates the absence of abrupt termination.

\[\begin{align*} \KEY{Funcon} \quad & \NAMEDECL{finalise-abrupting}( \VAR{X} : \TO \VAR{T}) : \TO \VAR{T} \mid \NAMEHYPER{../../../Values/Primitive}{Null}{null-type} \\&\quad \leadsto \NAMEREF{handle-abrupt} ( \VAR{X}, \NAMEHYPER{../../../Values/Primitive}{Null}{null-value} ) \end{align*}\]

\(\SHADE{\NAMEREF{finalise-abrupting} ( \VAR{X} )}\) handles abrupt termination of \(\SHADE{\VAR{X}}\) for any reason.

\[\begin{align*} \KEY{Funcon} \quad & \NAMEDECL{abrupt}( \_ : \NAMEHYPER{../../../Values}{Value-Types}{values}) : \TO \NAMEHYPER{../../../Values}{Value-Types}{empty-type} \end{align*}\]

\(\SHADE{\NAMEREF{abrupt} ( \VAR{V} )}\) terminates abruptly for reason \(\SHADE{\VAR{V}}\).

\[\begin{align*} \KEY{Rule} \quad & \NAMEREF{abrupt} ( \VAR{V} : \NAMEHYPER{../../../Values}{Value-Types}{values} ) \xrightarrow{\NAMEREF{abrupted}( \VAR{V} )}_{} \NAMEREF{stuck} \end{align*}\] \[\begin{align*} \KEY{Funcon} \quad & \NAMEDECL{handle-abrupt}( \_ : \VAR{T}' \TO \VAR{T}, \_ : \VAR{T}'' \TO \VAR{T}) : \VAR{T}' \TO \VAR{T} \end{align*}\]

\(\SHADE{\NAMEREF{handle-abrupt} ( \VAR{X}, \VAR{Y} )}\) first evaluates \(\SHADE{\VAR{X}}\). If \(\SHADE{\VAR{X}}\) terminates normally with value \(\SHADE{\VAR{V}}\), then \(\SHADE{\VAR{V}}\) is returned and \(\SHADE{\VAR{Y}}\) is ignored. If \(\SHADE{\VAR{X}}\) terminates abruptly for reason \(\SHADE{\VAR{V}}\), then \(\SHADE{\VAR{Y}}\) is executed with \(\SHADE{\VAR{V}}\) as \(\SHADE{\NAMEHYPER{../../Normal}{Giving}{given}}\) value.

\(\SHADE{\NAMEREF{handle-abrupt} ( \VAR{X}, \VAR{Y} )}\) is associative, with \(\SHADE{\NAMEREF{abrupt} ( \NAMEHYPER{../../Normal}{Giving}{given} )}\) as left and right unit. \(\SHADE{\NAMEREF{handle-abrupt} ( \VAR{X}, \NAMEHYPER{../.}{Failing}{else} ( \VAR{Y}, \NAMEREF{abrupt} ( \NAMEHYPER{../../Normal}{Giving}{given} ) ) )}\) ensures propagation of abrupt termination for the given reason if \(\SHADE{\VAR{Y}}\) fails

\[\begin{align*} \KEY{Rule} \quad & \RULE{ & \VAR{X} \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \VAR{X}' }{ & \NAMEREF{handle-abrupt} ( \VAR{X}, \VAR{Y} ) \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \NAMEREF{handle-abrupt} ( \VAR{X}', \VAR{Y} ) } \\ \KEY{Rule} \quad & \RULE{ & \VAR{X} \xrightarrow{\NAMEREF{abrupted}( \VAR{V} : \VAR{T}'' )}_{} \VAR{X}' }{ & \NAMEREF{handle-abrupt} ( \VAR{X}, \VAR{Y} ) \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \NAMEHYPER{../../Normal}{Giving}{give} ( \VAR{V}, \VAR{Y} ) } \\ \KEY{Rule} \quad & \NAMEREF{handle-abrupt} ( \VAR{V} : \VAR{T}, \VAR{Y} ) \leadsto \VAR{V} \end{align*}\] \[\begin{align*} \KEY{Funcon} \quad & \NAMEDECL{finally}( \_ : \TO \VAR{T}, \_ : \TO \NAMEHYPER{../../../Values/Primitive}{Null}{null-type}) : \TO \VAR{T} \end{align*}\]

\(\SHADE{\NAMEREF{finally} ( \VAR{X}, \VAR{Y} )}\) first executes \(\SHADE{\VAR{X}}\). If \(\SHADE{\VAR{X}}\) terminates normally with value \(\SHADE{\VAR{V}}\), then \(\SHADE{\VAR{Y}}\) is executed before terminating normally with value \(\SHADE{\VAR{V}}\). If \(\SHADE{\VAR{X}}\) terminates abruptly for reason \(\SHADE{\VAR{V}}\), then \(\SHADE{\VAR{Y}}\) is executed before terminating abruptly with the same reason \(\SHADE{\VAR{V}}\).

\[\begin{align*} \KEY{Rule} \quad & \RULE{ & \VAR{X} \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \VAR{X}' }{ & \NAMEREF{finally} ( \VAR{X}, \VAR{Y} ) \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \NAMEREF{finally} ( \VAR{X}', \VAR{Y} ) } \\ \KEY{Rule} \quad & \RULE{ & \VAR{X} \xrightarrow{\NAMEREF{abrupted}( \VAR{V} : \NAMEHYPER{../../../Values}{Value-Types}{values} )}_{} \VAR{X}' }{ & \NAMEREF{finally} ( \VAR{X}, \VAR{Y} ) \xrightarrow{\NAMEREF{abrupted}( \ )}_{} \NAMEHYPER{../../Normal}{Flowing}{sequential} ( \VAR{Y}, \NAMEREF{abrupt} ( \VAR{V} ) ) } \\ \KEY{Rule} \quad & \NAMEREF{finally} ( \VAR{V} : \VAR{T}, \VAR{Y} ) \leadsto \NAMEHYPER{../../Normal}{Flowing}{sequential} ( \VAR{Y}, \VAR{V} ) \end{align*}\]